Engagesmart (ESMT) 424B7 Prospectus with selling stockholder info

Filed pursuant to Rule 424(b)(7)
Registration No. 333-333-270090

PROSPECTUS SUPPLEMENT

(to Prospectus dated February 28, 2023)

8,000,000 Shares

Common Stock

The selling stockholders identified in this prospectus supplement are offering 8,000,000 shares of our common stock. We are not selling any shares of common stock in this offering and will not receive any of the proceeds from the shares of common stock sold by the selling stockholders.

Our common stock is listed on the New York Stock Exchange (“NYSE”) under the symbol “ESMT.” On February 28, 2023, the last reported sale price of shares of our common stock on the NYSE was $ 21.04 per share.

We are an “emerging growth company” as defined under the U.S. federal securities laws and, as such, are subject to reduced public company disclosure standards. See “Prospectus Supplement Summary—Implications of Being an Emerging Growth Company.”

	Per Share		Total
Public offering price	$	19.0000	$	152,000,000
Underwriting discounts and commissions(1)(2)	$	0.8075	$	6,399,438
Proceeds to selling stockholders, before expenses	$	18.1925	$	145,600,563

(1) See “Underwriting” beginning on page S-18 of this prospectus supplement for a description of the compensation payable to the underwriters.

(2) No underwriting discounts or commissions will be paid with respect to the 75,000 shares of our common stock sold by Cassandra Hudson, our Chief Financial Officer.

Certain of the selling stockholders have granted the underwriters an option for a period of 30 days to purchase up to 1,200,000 additional shares of our common stock.

Investing in our common stock involves a high degree of risk. See the section entitled “Risk Factors” beginning on page S-5 of this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

The underwriters expect to deliver the shares to purchasers on or about March 3, 2023.

Goldman Sachs & Co. LLC J.P. Morgan BofA Securities Citigroup

Deutsche Bank Securities Raymond James Truist Securities William Blair

KeyBanc Capital Markets Needham & Company Penserra Securities LLC Roberts & Ryan R. Seelaus & Co., LLC

The date of this prospectus supplement is February 28, 2023

TABLE OF CONTENTS

	Page
PROSPECTUS SUPPLEMENT
ABOUT THIS PROSPECTUS SUPPLEMENT		S-1
PROSPECTUS SUPPLEMENT SUMMARY		S-2
THE OFFERING		S-4
RISK FACTORS		S-5
FORWARD-LOOKING STATEMENTS		S-8
USE OF PROCEEDS		S-10
DIVIDEND POLICY		S-11
SELLING STOCKHOLDERS		S-12
MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS		S-14
UNDERWRITING		S-18
LEGAL MATTERS		S-24
EXPERTS		S-24
WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE		S-24

	Page
PROSPECTUS
ABOUT THIS PROSPECTUS		1
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS		2
WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE		3
PROSPECTUS SUMMARY		4
RISK FACTORS		5
USE OF PROCEEDS		6
DESCRIPTION OF CAPITAL STOCK		7
DESCRIPTION OF DEBT SECURITIES		14
DESCRIPTION OF OTHER SECURITIES		22
GLOBAL SECURITIES		23
SELLING SECURITYHOLDERS		27
PLAN OF DISTRIBUTION		28
LEGAL MATTERS		29
EXPERTS		29

ABOUT THIS PROSPECTUS SUPPLEMENT

On February 28, 2023, we filed with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-3 (File No. 333-270090) utilizing a shelf registration process relating to certain securities, including the securities described in this prospectus supplement, which registration statement became effective automatically upon filing.

This document contains two parts. The first part is this prospectus supplement, which describes the specific terms of this offering and also supplements and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part is the accompanying prospectus, which provides more general information, some of which may not apply to this offering. If the information contained in this prospectus supplement differs or varies from the information contained in the accompanying prospectus, you should rely on the information set forth in this prospectus supplement.

We, the selling stockholders and the underwriters have not authorized anyone to provide you with information or to make any representation other than the information and representations contained or incorporated by reference in this prospectus supplement and the accompanying prospectus and the documents incorporated by reference herein and therein, along with the information contained in any permitted free writing prospectuses we have authorized for use in connection with this offering. We, the selling stockholders and the underwriters take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you.

The selling stockholders and the underwriters are offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted. For investors outside the United States we, the selling stockholders and the underwriters have not done anything that would permit this offering or possession or distribution of this prospectus supplement, the accompanying prospectus and in any free writing prospectus that we have authorized for use in connection with this offering in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus supplement, the accompanying prospectus and any free writing prospectus that we have authorized for use in connection with this offering must inform themselves about, and observe any restrictions relating to, the offering of the shares of common stock and the distribution of this prospectus supplement, the accompanying prospectus and any free writing prospectus that we have authorized for use in connection with this offering outside the United States.

The information contained in this prospectus supplement and the accompanying prospectus is accurate only as of the date of this prospectus supplement or the date of the accompanying prospectus, as applicable, and the information in the documents incorporated by reference in this prospectus supplement and the accompanying prospectus is accurate only as of the date of those respective documents, regardless of the time of delivery of this prospectus supplement and the accompanying prospectus or of any sale of our common stock. Our business, financial condition, results of operations and prospects may have changed since those dates. It is important for you to read and consider all information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus in making your investment decision. You should read this prospectus supplement, the accompanying prospectus and any free writing prospectus that we have authorized for use in connection with this offering, as well as the documents incorporated by reference herein and therein and the additional information described under “Where You Can Find More Information; Incorporation by Reference” in this prospectus supplement and in the accompanying prospectus, before investing in our common stock.

Unless otherwise indicated or the context otherwise requires, references in this prospectus supplement and the accompanying prospectus to “EngageSmart,” “we,” “us,” “our,” “our company,” “Company,” and “our business” refer to EngageSmart, Inc.

S-1

PROSPECTUS SUPPLEMENT SUMMARY

This summary is not complete and does not contain all of the information that you should consider in making your investment decision. Before investing in our common stock, you should carefully read the entire prospectus supplement and the prospectus and the documents incorporated by reference in this prospectus supplement carefully, including “Risk Factors,” “Management’s Discussion and Analysis of Our Financial Condition and Results of Operations” and our financial statements and related notes incorporated by reference in this prospectus supplement.

Overview

We are a leading provider of vertically tailored customer engagement software and integrated payments solutions. At EngageSmart, our mission is to simplify customer and client engagement to allow our customers to focus resources on initiatives that improve their businesses and better serve their communities. We offer single instance, multi-tenant, true Software-as-a-Service (“SaaS”) vertical solutions that are designed to simplify our customers’ engagement with their clients by driving digital adoption and self-service. As of December 31, 2022, EngageSmart serves approximately 99,300 customers in the SMB Solutions segment and approximately 3,300 customers in the Enterprise Solutions segment across several core verticals: Health & Wellness, Government, Utilities, Financial Services, Healthcare and Giving. Our SaaS solutions are purpose-built for each of our verticals and they simplify and automate mission-critical workflows such as scheduling, client onboarding, client communication, paperless billing, and electronic payment processing. Our solutions transform our customers’ digital engagement and empower them to manage, improve, and grow their businesses.

Company Information

We were initially formed as Hancock Parent, LLC, a Delaware limited liability company, on December 7, 2018. On January 24, 2020, Hancock Parent, LLC changed its name to EngageSmart, LLC. Prior to the closing of our initial public offering on September 27, 2021, EngageSmart, LLC converted into a Delaware corporation pursuant to a statutory conversion and changed its name to EngageSmart, Inc. Our offices are located at 30 Braintree Hill Office Park, Suite 101, Braintree, Massachusetts 02184. Our telephone number is (781) 848-3733. Our corporate website address is www.engagesmart.com. Information contained on, or accessible through, our website shall not be deemed incorporated into and is not a part of this prospectus supplement. We have included our website in this prospectus supplement solely as an inactive textual reference.

This prospectus supplement includes our trademarks, service marks, and trade names, including but not limited to EngageSmart, InvoiceCloud, SimplePractice, HealthPay24 and DonorDrive, and our logo, which are protected under applicable intellectual property laws. This prospectus supplement also contains trademarks, service marks, and trade names of other companies, which are the property of their respective owners. We do not intend our use or display of other parties’ trademarks, service marks, or trade names to imply, and such use or display should not be construed to imply, a relationship with, or endorsement or sponsorship of us by, these other parties. Solely for convenience, trademarks, service marks, and trade names referred to in this prospectus supplement may appear without the ^®, ^™, or SM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent permitted under applicable law, our rights or the right of the applicable licensor to these trademarks, service marks, and trade names.

S-2

Implications of Being an Emerging Growth Company

We qualify as an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, as amended. As an “emerging growth company,” we may take advantage of reduced reporting requirements that are otherwise not applicable to public companies. These provisions include, but are not limited to:

• not being required to comply with the auditor attestation requirements of the Sarbanes-Oxley Act of 2002, as amended;

• reduced disclosure obligations regarding executive compensation in our periodic reports, proxy statements, and registration statements; and

• exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved.

We may take advantage of these provisions until the earliest of: (i) the last day of the first fiscal year in which our annual gross revenues are $1.235 billion or more; (ii) the date on which we have, during the previous three-year period, issued more than $1.0 billion in non-convertible debt securities; (iii) the date on which we are deemed to be a “large accelerated filer,” which will occur as of the end of any fiscal year in which we have an aggregate market value of our common stock held by non-affiliates of $700 million or more as of the last business day of our most recently completed second fiscal quarter; and (iv) December 31, 2026.

S-3

THE OFFERING

Common stock offered by the selling stockholders 8,000,000 shares.

Common stock outstanding after this offering 166,081,011 shares.

Underwriters’ option to purchase additional shares Certain of the selling stockholders have granted the underwriters a 30-day option to purchase up to an additional 1,200,000 shares of our common stock at the public offering price, less the underwriting discounts and commissions.

Use of proceeds The selling stockholders will receive all of the net proceeds from the sale of shares of common stock by them in this offering. See “Use of Proceeds.”

Risk factors See “Risk Factors” beginning on page S-5.

NYSE symbol “ESMT”

The number of shares of common stock that will be outstanding after this offering is based on 166,081,011 shares of common stock outstanding as of December 31, 2022 and excludes:

• 4,723,325 shares of our common stock issuable upon the exercise of stock options outstanding as of December 31, 2022, at a weighted average exercise price of $4.65 per share;

• 2,336,745 shares of our common stock issuable upon the vesting and settlement of restricted stock units (the “RSUs”) outstanding as of December 31, 2022;

• 897,382 shares of our common stock issuable upon the vesting and settlement of RSUs granted subsequent to December 31, 2022 (310,033 of which were granted to Robert P. Bennett, our Chief Executive Officer and a director, 112,739 of which were granted to Cassandra Hudson, our Chief Financial Officer, and 124,011 of which were granted to our other executive officers);

• 11,456,835 shares of our common stock reserved for future issuance under our 2021 Incentive Award Plan (the “2021 Plan”) as of December 31, 2022 (which number of shares excludes the shares subject to the RSUs referenced above that were granted subsequent to December 31, 2022), as well as any future increases in the number of shares of our common stock reserved for issuance under the 2021 Plan; and

• 2,155,456 shares of our common stock reserved for future issuance under our 2021 Employee Stock Purchase Plan (the “ESPP”) as of December 31, 2022, as well as any future increases in the number of shares of our common stock reserved for issuance under the ESPP.

Unless otherwise indicated, all information in this prospectus supplement assumes or gives effect to:

• no exercise of the outstanding options or settlement of the outstanding RSUs referred to above; and

• no exercise of the underwriters’ option to purchase additional shares from the selling stockholders.

S-4

RISK FACTORS

Investing in our common stock involves a high degree of risk. You should carefully consider the risks and uncertainties described in this prospectus supplement and the accompanying prospectus before deciding to purchase our common stock. In addition, you should carefully consider, among other things, the section titled “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2022, which is incorporated herein by reference, as well as any amendment or update thereto reflected in our subsequent filings with the SEC. You should consider carefully the risk factors discussed therein and below, and all other information contained in or incorporated by reference in this prospectus supplement, before making an investment decision. The occurrence of any such risks may adversely impact our business, financial condition and operating results. As a result, the trading price of our common stock could decline and you could lose part or all of your investment.

Risks Related to the Offering

Our stock price may fluctuate significantly and purchasers of our common stock could incur substantial losses.

The market price of our common stock could vary significantly as a result of a number of factors, some of which are beyond our control. In the event of a drop in the market price of our common stock, you could lose a substantial part or all of your investment in our common stock. The following factors could affect our stock price:

• our operating and financial performance and prospects;

• quarterly variations in the rate of growth (if any) of our financial indicators, such as net income per share, net income and revenues;

• the public reaction to our press releases, our other public announcements and our filings with the SEC;

• strategic actions by our competitors;

• changes in operating performance and the stock market valuations of other companies;

• overall conditions in our industry and the markets in which we operate;

• announcements related to litigation;

• our failure to meet revenue or earnings estimates made by research analysts or other investors;

• changes in revenue or earnings estimates, or changes in recommendations or withdrawal of research coverage, by equity research analysts;

• speculation in the press or investment community;

• issuance of new or updated research or reports by securities analysts;

• sales of our common stock by us or our stockholders, or the perception that such sales may occur;

• changes in accounting principles, policies, guidance, interpretations, or standards;

• additions or departures of key management personnel;

• actions by our stockholders;

• general market conditions;

• economic, legal and regulatory factors unrelated to our performance;

• announcement by us or our competitors of significant acquisitions, strategic partnerships, joint ventures or capital commitments;

S-5

• security breaches impacting us or other similar companies;

• expiration of contractual lock-up agreements with our executive officers, directors and stockholders; and

• material weaknesses in our internal control over financial reporting.

The stock markets in general have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. These broad market fluctuations may adversely affect the trading price of our common stock. Securities class action litigation has often been instituted against companies following periods of volatility in the overall market and in the market price of a company’s securities. Such litigation, if instituted against us, could result in very substantial costs, divert our management’s attention and resources and harm our business, financial condition, and results of operations.

None of the proceeds from the sale of shares of our common stock by the selling stockholders in this offering will be available to us to fund our operations.

We will not receive any proceeds from the sale of shares of our common stock by the selling stockholders in this offering. The selling stockholders will receive all proceeds from the sale of such shares. Consequently, none of the proceeds from such sale by the selling stockholders will be available to us to fund our operations, capital expenditures, compensation plans or acquisition opportunities. See “Use of Proceeds.”

General Atlantic (IC), L.P. (“General Atlantic”) has significant influence over EngageSmart, including control over decisions that require the approval of stockholders, which could limit your ability to influence the outcome of matters submitted to stockholders for a vote.

As of December 31, 2022, General Atlantic owned approximately 59% of the outstanding shares of our common stock. As long as General Atlantic owns or controls a majority of our outstanding voting power, General Atlantic will have the ability to exercise substantial control over all corporate actions requiring stockholder approval, irrespective of how our other stockholders may vote, including:

• the election and removal of directors and the size of our board of directors;

• any amendment of our articles of incorporation or bylaws; or

• the approval of mergers and other significant corporate transactions, including a sale of substantially all of our assets.

Moreover, ownership of our shares by General Atlantic may also adversely affect the trading price for our common stock to the extent investors perceive disadvantages in owning shares of a company with a controlling stockholder. For example, the concentration of ownership held by General Atlantic could delay, defer, or prevent a change in control of our company or impede a merger, takeover, or other business combination which may otherwise be favorable for us. In addition, directors appointed by General Atlantic currently comprise a majority of the members of our board of directors. General Atlantic is also in the business of making investments in companies and may, from time to time, acquire interests in businesses that directly or indirectly compete with our business, as well as businesses that are significant existing or potential customers. Some of the companies in which General Atlantic invests may compete with us. General Atlantic may acquire or seek to acquire assets complementary to our business that we seek to acquire and, as a result, those acquisition opportunities may not be available to us or may be more expensive for us to pursue, and as a result, the interests of General Atlantic may not coincide with the interests of our other stockholders. So long as General Atlantic continues to directly or indirectly own a significant amount of our equity, even if such amount is less than 50%, General Atlantic will continue to be able to substantially influence or effectively control our ability to enter into corporate transactions.

S-6

A portion of our total outstanding shares are restricted from immediate resale but may be sold into the market in the near future. This could cause the market price of our common stock to drop significantly, even if our business is doing well.

Sales of a substantial number of shares of our common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock. Following the consummation of this offering, we, our executive officers and directors, and the selling stockholders will be subject to a 75-day lock-up period provided under lock-up agreements executed in connection with this offering. See “Underwriting.” All of these shares will, however, be able to be resold after the expiration of the lock-up period, as well as pursuant to customary exceptions thereto or upon the waiver of the lock-up agreement by the representatives. General Atlantic, Summit Partners, and Robert P. Bennett, our Chief Executive Officer and a director, have certain rights to require us to register the sale of common stock held by such stockholders, including in connection with underwritten offerings, subject to the terms of the registration rights agreement. Sales of significant amounts of stock in the public market or the perception that such sales may occur, could adversely affect prevailing market prices of our common stock or make it more difficult for you to sell your shares of common stock at a time and price that you deem appropriate. The market price of our common stock could decline if the holders of currently restricted shares sell them or are perceived by the market as intending to sell them.

S-7

FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus, and the documents we have filed with the SEC that are incorporated by reference in this prospectus supplement and the accompanying prospectus contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the”Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements other than statements of historical facts contained or incorporated by reference in this prospectus supplement may be forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “targets,” “projects,” “contemplates,” “believes,” “estimates,” “forecasts,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. Forward-looking statements contained or incorporated by reference in this prospectus supplement include, but are not limited to statements regarding our future results of operations and financial position, industry and business trends, equity compensation, business strategy, plans, market growth and our objectives for future operations, including related to digital adoption of our software solutions, customer acquisition strategies, investment in new products and enhancement of existing products, expansion into new verticals and the pursuit of select acquisitions and/or dispositions.

The forward-looking statements included or incorporated by reference in this prospectus supplement are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. Forward-looking statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to:

• risks related to our ability to sustain our rapid growth;

• our ability to manage our infrastructure to support future growth;

• risks related to the effectiveness of our risk management efforts to prevent fraudulent activities;

• risks related to our ability to attract new customers or convert trial customers into paying customers;

• risks related to our ability to introduce new features or services successfully and to make enhancements to our solutions;

• risks related to any decline in our customer renewals or failure to convince our customers to broaden their use of solutions and related services;

• risks related to anticipated increases to our operating expenses and our ability to sustain profitability;

• our ability to adapt and respond effectively to rapidly changing technology, evolving industry standards and regulations, and changing business needs, requirements, or preferences;

• risks related to real or perceived errors, failures, or bugs in our solutions;

• our ability to face intense competition and to maintain or expand market share within our industry;

• our ability to establish, grow and maintain strategic partnerships;

• our ability to meet the expectations of securities analysts or investors with respect to our operating results;

• our ability to integrate acquired businesses and technologies successfully or achieve the expected benefits of such acquisitions;

• risks related to general economic conditions (including inflation), both domestically and internationally, as well as economic conditions specifically affecting industries in which our customers operate; and

• the other important factors discussed in “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022, which is incorporated by reference herein.

S-8

The forward-looking statements in this prospectus supplement are based upon information available to us as of the date hereof, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

You should read this prospectus supplement and the documents incorporated by reference and filed with the SEC with the understanding that our actual future results, performance and achievements may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements. These forward-looking statements speak only as of the date hereof. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained in this prospectus supplement, whether as a result of any new information, future events or otherwise.

S-9

USE OF PROCEEDS

The selling stockholders will receive all of the net proceeds from the sale of shares of common stock by them in this offering. We are not selling any shares of common stock in this offering, and we will not receive any of the proceeds from any sale of shares in this offering by the selling stockholders.

S-10

DIVIDEND POLICY

We have never declared or paid, and do not anticipate declaring or paying, any cash dividends on our common stock. Any future determination as to the declaration and payment of dividends, will be at the discretion of our board of directors and will depend on then existing conditions, including our financial condition, operating results, contractual restrictions, capital requirements, business prospects, and other factors that our board of directors may deem relevant.

S-11

SELLING STOCKHOLDERS

The following table and footnotes set forth information with respect to the beneficial ownership of our common stock by the selling stockholders as of December 31, 2022, subject to certain assumptions set forth in the footnotes and as adjusted to reflect the sale of shares of common stock by the selling stockholders as set forth on the cover page of this prospectus supplement. Percentage of beneficial ownership before this offering is based on 166,081,011 shares of common stock outstanding as of December 31, 2022. Beneficial ownership is based on information furnished by the selling stockholders. Beneficial ownership and percentage ownership are determined in accordance with the rules of the SEC.

When we refer to the “selling stockholders” in this prospectus supplement, we include any pledgees, donees, assignees, transferees, successors and others who may hold any of the selling stockholder’s interest.

	Shares Beneficially Owned Prior to this Offering					Shares Being Offered				Shares Beneficially Owned After this Offering (assuming no exercise of option)				Shares Beneficially Owned After this Offering (assuming full exercise of option)
Name of Selling Stockholder	Number		Percentage			Number (assuming no exercise of option)		Number (assuming full exercise of option)		Number		Percentage		Number		Percentage
Entities affiliated with General Atlantic (1)		97,209,436		58.5	%		6,025,515		6,937,896		91,183,921		54.9%		90,271,540		54.4%
Entities affiliated with Summit Partners (2)		26,926,752		16.2	%		1,669,052		1,921,779		25,257,700		15.2%		25,004,973		15.1%
Robert P. Bennett (3)		3,717,574		2.2	%		230,433		265,325		3,487,141		2.1%		3,452,249		2.1%
Cassandra Hudson (4)		436,473			*		75,000		75,000		361,473		*		361,473		*

* Represents beneficial ownership of less than 1.0%

(1) Consists of 97,209,436 shares of common stock held by General Atlantic (IC), L.P. (“GA IC”). Each of General Atlantic Partners 100, L.P. (“GAP 100”), General Atlantic Partners (Bermuda) EU, L.P. (“GAP Bermuda EU”), GAP Coinvestments III, LLC (“GAPCO III”), GAP Coinvestments IV, LLC (“GAPCO IV”), GAP Coinvestments V, LLC (“GAPCO V”) and GAP Coinvestments CDA, L.P. (“GAPCO CDA”, and collectively with GAP 100, GAP Bermuda EU, GAPCO IV, GAPCO V and GAPCO III, the “GA Funds”) share beneficial ownership of the shares held by GA IC. The general partner of GA IC is General Atlantic (SPV) GP, LLC (“GA SPV”). The general partner of GAP 100 is ultimately controlled by General Atlantic, L.P. (“GA LP”), which is controlled by the Management Committee of GASC MGP, LLC (the “Management Committee”). The general partner of GAP Bermuda EU is ultimately controlled by GAP (Bermuda) L.P. (“GAP Bermuda”), which is also controlled by the Management Committee. GA LP is the managing member of GAPCO III, GAPCO IV and GAPCO V, the general partner of GAPCO CDA and is the sole member of GA SPV. There are nine members of the Management Committee. GA IC, GA LP, GASC MGP, LLC, GAP Bermuda, GA SPV and the GA Funds (collectively, the “GA Group”) are a “group” within the meaning of Rule 13d-5 of the Securities Exchange Act of 1934, as amended. The address of the foregoing General Atlantic entities, other than GAP Bermuda EU and GAP Bermuda, is c/o General Atlantic Service Company, L.P., 55 East 52nd Street, 33rd Floor, New York, NY 10055. The address of GAP Bermuda EU and GAP Bermuda is Clarendon House, 2 Church Street, Hamilton HM 11, Bermuda. Each of the members of the Management Committee disclaims ownership of the shares except to the extent that he has a pecuniary interest therein.

(2) Based solely on information reported on a Schedule 13G jointly filed on February 4, 2022 by Summit Partners L.P., Summit Partners Growth Equity Fund VIII-A, L.P., Summit Partners Growth Equity Fund VIII-B, L.P., Summit Partners Entrepreneur Advisors Fund I, L.P., Summit Investors I, LLC, Summit Investors I (UK), L.P., Scott Collins and Peter Y. Chung. Summit Partners, L.P. is the managing member of Summit Partners GE VIII, LLC, which is the general partner of Summit Partners GE VIII, L.P., which is the general partner of each of Summit Partners Growth Equity Fund VIII-A, L.P. and Summit Partners Growth Equity Fund VIII-B, L.P. Summit Master Company, LLC is the (A) sole managing member of Summit Partners Entrepreneur Advisors GP, LLC, which is the general partner of Summit Partners

Entrepreneur Advisors Fund I, L.P., and (B) the managing member of Summit Investors Management, LLC, which is the manager of Summit Investors I, LLC and the general partner of Summit Investors I (UK), L.P. Summit Master Company, LLC, as the sole managing member of Summit Partners Entrepreneur Advisors GP, LLC and the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to

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Summit Partners, L.P. Investment decisions for Summit Partners, L.P. are made by its two-person Investment Committee, which is currently composed of Scott Collins and Peter Y. Chung. Summit Partners L.P., Scott Collins and Peter Y. Chung each have shared voting and dispositive power over 26,926,752 shares of our common stock. Summit Partners Growth Equity Fund VIII-A, L.P. has shared voting and dispositive power over 19,327,768 shares of our common stock. Summit Partners Growth Equity Fund VIII-B, L.P. has shared voting and dispositive power over 7,060,848 shares of our common stock. Summit Partners Entrepreneur Advisors Fund I, L.P. has shared voting and dispositive power over 128,222 shares of our common stock. Summit Investors I, LLC has shared voting and dispositive power over 370,024 shares of our common stock. Summit Investors I (UK), L.P. has shared voting and dispositive power over 39,890 shares of our common stock. The business address for each of the foregoing entities and individuals is 222 Berkeley Street, 18th Floor, Boston, Massachusetts 02116.

(3) Consists of (i) 976,192 shares of common stock held by Mr. Bennett, (ii) 150,000 shares of common stock held jointly by Mr. Bennett and Martha Bennett, Mr. Bennett’s spouse, (iii) 1,458,000 shares of common stock held by The Bennett Family 2020 Trust, of which John Burgess and Martha Bennett serve as trustees, (iv) 980,978 shares of common stock held by The Robert P. Bennett 2020 Grantor Retained Annuity Trust, of which Mr. Bennett serves as the sole trustee, (v) 150,000 shares of common stock underlying options held by Mr. Bennett that are currently exercisable or would be exercisable within 60 days of December 31, 2022, and (vi) 2,404 shares of common stock issuable upon the vesting and settlement within 60 days of December 31, 2022 of RSUs held by Mr. Bennett. Martha Bennett may be deemed to share voting and dispositive power with respect to the shares held by The Bennett Family 2020 Trust and the shares jointly held with Mr. Bennett.

(4) Consists of (i) 10,996 shares of common stock held by Ms. Hudson, (ii) 421,872 shares of common stock underlying options held by Ms. Hudson that are currently exercisable or would be exercisable within 60 days of December 31, 2022, and (iii) 3,605 shares of common stock issuable upon the vesting and settlement within 60 days of December 31, 2022 of RSUs held by Ms. Hudson.

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MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS

The following discussion is a summary of the material U.S. federal income tax consequences for Non-U.S. Holders (as defined below) of the purchase, ownership, and disposition of our common stock issued pursuant to this offering. This discussion does not purport to be a complete analysis of all potential tax effects relating thereto. The effects of other U.S. federal tax laws, such as estate and gift tax laws, and any applicable state, local, or non-U.S. tax laws are not discussed. This discussion is based on the U.S. Internal Revenue Code of 1986, as amended, (the “Code”), Treasury Regulations promulgated thereunder, judicial decisions, and published rulings and administrative pronouncements of the U.S. Internal Revenue Service (the “IRS”) in each case in effect as of the date hereof. These authorities may change or be subject to differing interpretations. Any such change or differing interpretation may be applied retroactively in a manner that could adversely affect a Non-U.S. Holder of our common stock. We have not requested and will not seek any ruling from the IRS regarding the matters discussed below. There can be no assurance the IRS or a court will not take a contrary position to that discussed below regarding the tax consequences of the purchase, ownership, and disposition of our common stock.

This discussion is limited to Non-U.S. Holders that hold our common stock as a “capital asset” within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion does not address all U.S. federal income tax consequences relevant to a Non-U.S. Holder’s particular circumstances, including the impact of the Medicare contribution tax on net investment income and the alternative minimum tax. In addition, it does not address consequences relevant to Non-U.S. Holders subject to special rules under the U.S. federal income tax laws, including, without limitation:

• U.S. expatriates and former citizens or long-term residents of the United States;

• persons holding our common stock as part of a hedge, straddle, or other risk reduction strategy or as part of a conversion transaction or other integrated investment;

• banks, insurance companies, and other financial institutions, regulated investment companies, or real estate investment trusts;

• brokers or dealers in securities or currencies;

• traders in securities or other persons that elect to use a mark-to-market method of accounting for their holdings in our stock;

• controlled foreign corporations (as defined in Section 957 of the Code), passive foreign investment companies (as defined in Section 1297 of the Code), and corporations that accumulate earnings to avoid U.S. federal income tax;

• partnerships or other entities or arrangements treated as partnerships for U.S. federal income tax purposes and other pass-through entities (and investors in such entities);

• tax-exempt organizations or governmental organizations;

• persons deemed to sell our common stock under the constructive sale provisions of the Code;

• persons who hold or receive our common stock pursuant to the exercise of any employee stock option or otherwise as compensation;

• pension plans or tax-exempt retirement plans;

• persons that own, or are deemed to own, more than five percent of our capital stock;

• “qualified foreign pension funds” as defined in Section 897(l)(2) of the Code and entities all of the interests of which are held by qualified foreign pension funds; and

• persons subject to special tax accounting rules as a result of any item of gross income with respect to the common stock being taken into account in an applicable financial statement (as defined in Section 451(b) of the Code).

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If an entity treated as a partnership for U.S. federal income tax purposes holds our common stock, the tax treatment of a partner in the partnership will depend on the status of the partner, the activities of the partnership, and certain determinations made at the partner level. Accordingly, partnerships holding our common stock and the partners in such partnerships should consult their tax advisors regarding the U.S. federal income tax consequences to them.

THIS DISCUSSION IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT TAX ADVICE. INVESTORS SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE APPLICATION OF THE U.S. FEDERAL INCOME TAX LAWS TO THEIR PARTICULAR SITUATIONS AS WELL AS ANY TAX CONSEQUENCES OF THE PURCHASE, OWNERSHIP, AND DISPOSITION OF OUR COMMON STOCK ARISING UNDER THE U.S. FEDERAL ESTATE OR GIFT TAX LAWS OR UNDER THE LAWS OF ANY STATE, LOCAL, OR NON-U.S. TAXING JURISDICTION OR UNDER ANY APPLICABLE INCOME TAX TREATY.

Definition of Non-U.S. Holder

For purposes of this discussion, a “Non-U.S. Holder” is any beneficial owner of our common stock that is neither a “United States Person” nor an entity treated as a partnership for U.S. federal income tax purposes. A United States Person is any person that, for U.S. federal income tax purposes, is or is treated as any of the following:

• an individual who is a citizen or resident of the United States;

• a corporation created or organized under the laws of the United States, any state thereof or the District of Columbia;

• an estate, the income of which is subject to U.S. federal income tax regardless of its source; or

• a trust that (1) is subject to the primary supervision of a U.S. court and which has one or more “United States persons” (as defined in Section 7701(a)(30) of the Code) that have the authority to control all substantial decisions of the trust, or (2) has a valid election in effect to be treated as a United States person under the applicable Treasury Regulations.

Distributions

As described in the section entitled “Dividend Policy,” we do not anticipate declaring or paying dividends to holders of our common stock in the foreseeable future. However, if we do make distributions of cash or property on our common stock, such distributions will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. Amounts not treated as dividends for U.S. federal income tax purposes will constitute a return of capital and first be applied against and reduce a Non-U.S. Holder’s adjusted tax basis in its common stock, but not below zero. Any excess will be treated as capital gain and will be treated as described below under “—Sale or other taxable disposition.”

Subject to the discussion below on effectively connected income, dividends paid to a Non-U.S. Holder of our common stock will be subject to U.S. federal withholding tax at a rate of 30% of the gross amount of the dividends (or such lower rate provided for by an applicable income tax treaty, provided the Non-U.S. Holder timely furnishes a valid IRS Form W-8BEN or W-8BEN-E (or other applicable documentation) certifying qualification for the lower treaty rate). A Non-U.S. Holder that does not timely furnish the required documentation, but that qualifies for a reduced treaty rate, may be able to obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS. Non-U.S. Holders should consult their tax advisors regarding their entitlement to benefits under any applicable income tax treaty.

If dividends paid to a Non-U.S. Holder are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, the Non-U.S. Holder

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maintains a permanent establishment in the United States to which such dividends are attributable), the Non-U.S. Holder generally will be exempt from the U.S. federal withholding tax described above. To claim the exemption, the Non-U.S. Holder must timely furnish to the applicable withholding agent a valid IRS Form W-8ECI, certifying that the dividends are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States.

Any such effectively connected dividends will be subject to U.S. federal income tax on a net income basis at the regular graduated rates. A Non-U.S. Holder that is a corporation also may be subject to a branch profits tax at a rate of 30% (or such lower rate provided for by an applicable income tax treaty) on such effectively connected dividends, as adjusted for certain items. Non-U.S. Holders should consult their tax advisors regarding any applicable tax treaties that may provide for different rules.

Sale or Other Taxable Disposition

Subject to the discussion below on information reporting, backup withholding and foreign accounts, a Non-U.S. Holder will generally not be subject to U.S. federal income tax on any gain realized upon the sale or other taxable disposition of our common stock unless:

• the gain is effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, the Non-U.S. Holder maintains a permanent establishment in the United States to which such gain is attributable);

• the Non-U.S. Holder is a nonresident alien individual present in the United States for a period or periods aggregating 183 days or more during the taxable year of the disposition and certain other requirements are met; or

• our common stock constitutes a U.S. real property interest (a “USRPI”) by reason of our status as a U.S. real property holding corporation, or a USRPHC, for U.S. federal income tax purposes.

Gain described in the first bullet point above generally will be subject to U.S. federal income tax on a net income basis at the rates applicable to United States persons. A Non-U.S. Holder that is a corporation also may be subject to a branch profits tax at a rate of 30% (or such lower rate provided for by an applicable income tax treaty) on such effectively connected gain, as adjusted for certain items.

A Non-U.S. Holder described in the second bullet point above will be subject to U.S. federal income tax at a rate of 30% (or such lower rate provided for by an applicable income tax treaty) on gain realized upon the sale or other taxable disposition of our common stock, which may be offset by U.S. source capital losses of the Non-U.S. Holder (even though the individual is not considered a resident of the United States), provided the Non-U.S. Holder has timely filed U.S. federal income tax returns with respect to such losses.

With respect to the third bullet point above, we believe we currently are not, and do not anticipate becoming, a USRPHC. Because the determination of whether we are a USRPHC depends, however, on the fair market value of our USRPIs relative to the fair market value of our non-U.S. real property interests and our other business assets, there can be no assurance we currently are not a USRPHC or will not become one in the future. Even if we are or were to become a USRPHC, gain arising from the sale or other taxable disposition by a Non-U.S. Holder of our common stock will not be subject to U.S. federal income tax if our common stock is “regularly traded,” as defined by applicable Treasury Regulations, on an established securities market, and such Non-U.S. Holder owned, actually and constructively, 5% or less of our common stock throughout the shorter of the five-year period ending on the date of the sale or other taxable disposition or the Non-U.S. Holder’s holding period.

Non-U.S. Holders should consult their tax advisors regarding potentially applicable income tax treaties that may provide for different rules.

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Information Reporting and Backup Withholding

Payments of dividends on our common stock, if any, will not be subject to backup withholding, provided the applicable withholding agent does not have actual knowledge or reason to know the holder is a United States person and the holder either certifies its non-U.S. status, such as by timely furnishing a valid IRS Form W-8BEN, W-8BEN-E or W-8ECI, or otherwise establishes an exemption. However, information returns are required to be filed with the IRS in connection with any distributions on our common stock paid to the Non-U.S. Holder, regardless of whether such distributions constitute dividends or whether any tax was actually withheld. In addition, proceeds of the sale or other taxable disposition of our common stock within the United States or conducted through certain U.S.-related brokers generally will not be subject to backup withholding or information reporting, if the applicable withholding agent receives the certification described above and does not have actual knowledge or reason to know that such holder is a United States person, or the holder otherwise establishes an exemption. Proceeds of a disposition of our common stock conducted through a non-U.S. office of a non-U.S. broker generally will not be subject to backup withholding or information reporting.

Copies of information returns that are filed with the IRS may also be made available under the provisions of an applicable treaty or agreement to the tax authorities of the country in which the Non-U.S. Holder resides or is established.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a Non-U.S. Holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

Additional Withholding Tax on Payments Made to Foreign Accounts

Withholding taxes may be imposed under Sections 1471 to 1474 of the Code (such Sections commonly referred to as the Foreign Account Tax Compliance Act (“FATCA”)), on certain types of payments made to non-U.S. financial institutions and certain other non-U.S. entities. Specifically, a 30% withholding tax may be imposed on dividends on, or (subject to the proposed Treasury Regulations discussed below) gross proceeds from the sale or other disposition of, our common stock paid to a “foreign financial institution” or a “non-financial foreign entity” (each as defined in the Code), unless (1) the foreign financial institution undertakes certain diligence and reporting obligations, (2) the non-financial foreign entity either certifies it does not have any “substantial United States owners” (as defined in the Code) or furnishes identifying information regarding each substantial United States owner, or (3) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in (1) above, it must enter into an agreement with the U.S. Department of the Treasury requiring, among other things, that it undertake to identify accounts held by certain “specified United States persons” or “United States-owned foreign entities” (each as defined in the Code), annually report certain information about such accounts, and withhold 30% on certain payments to non-compliant foreign financial institutions and certain other account holders. Foreign financial institutions located in jurisdictions that have an intergovernmental agreement with the United States governing FATCA may be subject to different rules.

Under the applicable Treasury Regulations and administrative guidance, withholding under FATCA generally applies to payments of dividends on our common stock. The U.S. Department of the Treasury has issued proposed Treasury Regulations providing that the withholding provisions under FATCA do not apply with respect to the gross proceeds from a sale or other disposition of our common stock. In its preamble to such proposed regulations, the U.S. Department of the Treasury stated that taxpayers generally may rely on these proposed Treasury Regulations until final Treasury Regulations are issued.

Prospective investors should consult their tax advisors regarding the potential application of withholding under FATCA to their investment in our common stock.

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UNDERWRITING

We, the selling stockholders and the underwriters named below have entered into an underwriting agreement with respect to the shares of our common stock being offered pursuant to this prospectus supplement. Subject to certain conditions, each underwriter has severally agreed to purchase the number of shares of our common stock indicated in the following table. Goldman Sachs & Co. LLC and J.P. Morgan Securities LLC are representatives of the underwriters.

Underwriters	Number of Shares
Goldman Sachs & Co. LLC		2,196,080
J.P. Morgan Securities LLC		2,039,214
BofA Securities, Inc.		1,129,411
Citigroup Global Markets Inc.		752,941
Deutsche Bank Securities Inc.		414,118
Raymond James & Associates, Inc.		320,000
Truist Securities, Inc.		320,000
William Blair & Company, L.L.C.		320,000
KeyBanc Capital Markets Inc.		225,882
Needham & Company, LLC		225,882
Penserra Securities LLC		18,824
Roberts & Ryan Investments, Inc.		18,824
R. Seelaus & Co., LLC		18,824
Total		8,000,000

The underwriters are committed to take and pay for all of the shares of our common stock being offered, if any are taken, other than the shares of our common stock covered by the option described below unless and until this option is exercised.

The underwriters have an option to buy up to an additional 1,200,000 shares of our common stock from certain of the selling stockholders. They may exercise that option for 30 days. If any shares of our common stock are purchased pursuant to this option, the underwriters will severally purchase shares of our common stock in approximately the same proportion as set forth in the table above.

The following table shows the per share and total underwriting discounts and commissions to be paid to the underwriters by certain of the selling stockholders. Such amounts are shown assuming both no exercise and full exercise of the underwriters’ option to purchase 1,200,000 additional shares of our common stock. No underwriting discounts or commissions will be paid with respect to the 75,000 shares of our common stock sold by Ms. Hudson.

Paid by the Selling Stockholders

	No Exercise		Full Exercise
Per share	$	0.8075	$	0.8075
Total	$	6,399,438	$	7,368,438

The shares of our common stock sold by the underwriters to the public will initially be offered at the initial public offering price set forth on the cover of this prospectus. Any shares of our common stock sold by the underwriters to securities dealers may be sold at a discount of up to $0.4845 per share from the initial public offering price. After the initial offering of the shares of our common stock, the representatives may change the offering price and the other selling terms. The offering of the shares of our common stock by the underwriters is subject to receipt and acceptance and subject to the underwriters’ right to reject any order in whole or in part.

We, our executive officers and directors, and the selling stockholders have agreed with the underwriters, subject to certain exceptions, not to dispose of or hedge any of their shares of our common stock or securities convertible into

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or exchangeable for shares of our common stock during the period from the date of this prospectus supplement continuing to and including the date 75 days after the date of this prospectus supplement, except with the prior written consent of the representatives. This agreement does not apply to any existing employee benefit plans. Except for customary lock-up exceptions, including an exception allowing one of our officers and directors to make sales under preexisting 10b5-1 plans and an exception permitting one of our directors to make limited sales to raise funds for the payment of tax and remittance payments due as a result of the vesting or settlement of restricted stock units; there are no existing agreements between the underwriters and any of our stockholders who have executed a lock-up agreement providing consent to the sale of shares prior to the expiration of the lock-up period.

In connection with the offering, the underwriters may purchase and sell shares of our common stock in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in the offering, and a short position represents the amount of such sales that have not been covered by subsequent purchases. A “covered short position” is a short position that is not greater than the amount of additional shares for which the underwriters’ option described above may be exercised. The underwriters may cover any covered short position by either exercising their option to purchase additional shares or purchasing shares in the open market. In determining the source of shares to cover the covered short position, the underwriters will consider, among other things, the price of the shares available for purchase in the open market as compared to the price at which they may purchase additional shares pursuant to the option described above. “Naked” short sales are any short sales that create a short position greater than the amount of additional shares for which the option described above may be exercised. The underwriters must cover any such naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the common stock in the open market after pricing that could adversely affect investors who purchase in the offering. Stabilizing transactions consist of various bids for or purchases of common stock made by the underwriters in the open market prior to the completion of the offering.

The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representative has repurchased shares sold by or for the account of such underwriter in stabilizing or short covering transactions.

Purchases to cover a short position and stabilizing transactions, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market price of the company’s stock, and together with the imposition of the penalty bid, may stabilize, maintain or otherwise affect the market price of the common stock. As a result, the price of the common stock may be higher than the price that otherwise might exist in the open market. The underwriters are not required to engage in these activities and may end any of these activities at any time. These transactions may be effected on the NYSE, in the over-the-counter market or otherwise.

We have agreed to pay expenses incurred by the selling stockholders in connection with this offering, other than the underwriting discounts and commissions. The expenses of this offering that are payable by us will be approximately $1.3 million, which includes an amount not to exceed $40,000 that we have agreed to reimburse the underwriters for certain expenses incurred by them in connection with this offering.

We and the selling stockholders have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act.

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include sales and trading, commercial and investment banking, advisory, investment management, investment research, principal investment, hedging, market making, brokerage and other financial and non-financial activities and services. Certain of the underwriters and their respective affiliates have provided, and may in the future provide, a variety of these services to us and to persons and entities with relationships with us, for which they received or will receive customary fees and expenses.

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In the ordinary course of their various business activities, the underwriters and their respective affiliates, officers, directors and employees may purchase, sell or hold a broad array of investments and actively trade securities, derivatives, loans, commodities, currencies, credit default swaps and other financial instruments for their own account and for the accounts of their customers, and such investment and trading activities may involve or relate to our assets, securities and/or instruments (directly, as collateral securing other obligations or otherwise) and/or persons and entities with relationships with us. The underwriters and their respective affiliates may also communicate independent investment recommendations, market color or trading ideas and/or publish or express independent research views in respect of such assets, securities or instruments and may at any time hold, or recommend to clients that they should acquire, long and/or short positions in such assets, securities and instruments.

European Economic Area

In relation to each Member State of the European Economic Area (each a “Relevant Member State”), no shares of our common stock have been offered or will be offered pursuant to the offering to the public in that Relevant Member State prior to the publication of a prospectus in relation to the shares of our common stock which has been approved by the competent authority in that Relevant Member State or, where appropriate, approved in another Relevant Member State and notified to the competent authority in that Relevant Member State, all in accordance with the Prospectus Regulation, except that the shares of our common stock may be offered to the public in that Relevant Member State at any time under the following exemptions under the Prospectus Regulation:

a) to any legal entity which is a qualified investor as defined under Article 2 of the Prospectus Regulation;

b) to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the Prospectus Regulation), subject to obtaining the prior consent of the representative for any such offer; or

c) in any other circumstances falling within Article 1(4) of the Prospectus Regulation,

provided that no such offer of shares of our common stock shall require us, the selling stockholders or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation.

For the purposes of this provision, the expression an “offer to the public” in relation to the shares of our common stock in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and any shares of our common stock to be offered so as to enable an investor to decide to purchase any shares of our common stock, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129.

Each person in a Relevant Member State who receives any communication in respect of, or who acquires any shares of our common stock under, the Offering contemplated hereby will be deemed to have represented, warranted and agreed to and with each of the underwriters and their affiliates, us and the selling stockholders that:

a) it is a qualified investor within the meaning of the Prospectus Regulation; and

b) in the case of any shares of our common stock acquired by it as a financial intermediary, as that term is used in Article 5 of the Prospectus Regulation, (i) the shares of our common stock acquired by it in the Offering have not been acquired on a non-discretionary basis on behalf of, nor have they been acquired with a view to their offer or resale to, persons in any Relevant Member State other than qualified investors, as that term is defined in the Prospectus Regulation, or have been acquired in other circumstances falling within the points (a) to (d) of Article 1(4) of the Prospectus Regulation and the prior consent of the representative has been given to the offer or resale; or (ii) where the shares of our

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common stock have been acquired by it on behalf of persons in any Relevant Member State other than qualified investors, the offer of those shares of our common stock to it is not treated under the Prospectus Regulation as having been made to such persons.

We, the selling stockholders, the underwriters and their affiliates, and others will rely upon the truth and accuracy of the foregoing representation, acknowledgement and agreement. Notwithstanding the above, a person who is not a qualified investor and who has notified the representative of such fact in writing may, with the prior consent of the representative, be permitted to acquire shares of common stock in the offering.

United Kingdom

This prospectus and any other material in relation to the common shares described herein is only being distributed to, and is only directed at, and any investment or investment activity to which this prospectus relates is available only to, and will be engaged in only with persons who are (i) persons having professional experience in matters relating to investments who fall within the definition of investment professionals in Article 19(5) of the FPO; or (ii) high net worth entities falling within Article 49(2)(a) to (d) of the FPO; (iii) outside the UK; or (iv) persons to whom an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the FSMA) in connection with the issue or sale of any shares of our common stock may otherwise lawfully be communicated or caused to be communicated, (all such persons together being referred to as “Relevant Persons”). The shares of our common stock are only available in the UK to, and any invitation, offer or agreement to purchase or otherwise acquire the shares of our common stock will be engaged in only with, the Relevant Persons. This prospectus and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other person in the UK. Any person in the UK that is not a Relevant Person should not act or rely on this prospectus or any of its contents.

No shares of our common stock have been offered or will be offered pursuant to the offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the shares of our common stock which has been approved by the Financial Conduct Authority, except that the shares of our common stock may be offered to the public in the United Kingdom at any time:

a) to any legal entity which is a qualified investor as defined under Article 2 of the UK Prospectus Regulation;

b) to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the UK Prospectus Regulation), subject to obtaining the prior consent of the representative for any such offer; or

c) in any other circumstances falling within Section 86 of the FSMA.

Provided that no such offer of the shares of our common stock shall require us, the selling stockholders and/or any underwriters or any of their affiliates to publish a prospectus pursuant to Section 85 of the FSMA or supplement a prospectus pursuant to Article 23 of the UK Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to the shares of our common stock in the United Kingdom means the communication in any form and by any means of sufficient information on the terms of the offer and any shares of our common stock to be offered so as to enable an investor to decide to purchase or subscribe for any shares of our common stock, and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

Each person in the UK who acquires any shares of our common stock in the offering or to whom any offer is made will be deemed to have represented, acknowledged and agreed to and with us, the selling stockholders, the underwriters and their affiliates that it meets the criteria outlined in this section.

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Canada

Shares of our common stock may be sold in Canada only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions, and Ongoing Registrant Obligations. Any resale of the shares of our common stock must be made in accordance with an exemption form, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

Hong Kong

Shares of our common stock may not be offered or sold in Hong Kong by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies (Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32 of the Laws of Hong Kong) (“Companies (Winding Up and Miscellaneous Provisions) Ordinance”) or which do not constitute an invitation to the public within the meaning of the Securities and Futures Ordinance (Cap. 571 of the Laws of Hong Kong) (“Securities and Futures Ordinance”), or (ii) to “professional investors” as defined in the Securities and Futures Ordinance and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance, and no advertisement, invitation or document relating to the shares of our common stock may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to shares of our common stock which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” in Hong Kong as defined in the Securities and Futures Ordinance and any rules made thereunder.

Singapore

This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares of our common stock may not be circulated or distributed, nor may the shares of our common stock be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor (as defined under Section 4A of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”)) under Section 274 of the SFA, (ii) to a relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to conditions set forth in the SFA.

Where the shares of our common stock are subscribed or purchased under Section 275 of the SFA by a relevant person which is a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole

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business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor, the securities (as defined in Section 239(1) of the SFA) of that corporation shall not be transferable for 6 months after that corporation has acquired the shares of our common stock under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer in that corporation’s securities pursuant to Section 275(1A) of the SFA, (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore (“Regulation 32”).

Where the shares of our common stock are subscribed or purchased under Section 275 of the SFA by a relevant person which is a trust (where the trustee is not an accredited investor (as defined in Section 4A of the SFA)) whose sole purpose is to hold investments and each beneficiary of the trust is an accredited investor, the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferable for 6 months after that trust has acquired the shares of our common stock under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer that is made on terms that such rights or interest are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction (whether such amount is to be paid for in cash or by exchange of securities or other assets), (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32.

Japan

The shares of our common stock have not been and will not be registered under the Financial Instruments and Exchange Act of Japan (Act No. 25 of 1948, as amended), or the FIEA. The shares of our common stock may not be offered or sold, directly or indirectly, in Japan or to or for the benefit of any resident of Japan (including any person resident in Japan or any corporation or other entity organized under the laws of Japan) or to others for reoffering or resale, directly or indirectly, in Japan or to or for the benefit of any resident of Japan, except pursuant to an exemption from the registration requirements of the FIEA and otherwise in compliance with any relevant laws and regulations of Japan.

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LEGAL MATTERS

The validity of the shares of common stock offered hereby will be passed upon for us by Latham & Watkins LLP. Fenwick & West LLP is acting as counsel for the underwriters in connection with this offering. Each of Paul, Weiss, Rifkind, Wharton & Garrison LLP, Kirkland & Ellis LLP, Maples and Calder (Cayman) LLP and Whalen LLP, respectively, is acting as counsel for certain of the selling stockholders in connection with this offering.

EXPERTS

The financial statements of EngageSmart, Inc. and subsidiaries incorporated by reference in this Prospectus Supplement, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report. Such financial statements are incorporated by reference in reliance upon the report of such firm, given upon their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at www.sec.gov. We maintain a website at www.engagesmart.com. These website addresses, and the website addresses included in any documents incorporated by reference herein, are not intended to function as hyperlinks, and the information contained on such websites and on the SEC’s website is not incorporated by reference in this prospectus supplement and the accompanying prospectus and you should not consider it a part of this prospectus supplement and the accompanying prospectus.

This prospectus supplement and the accompanying prospectus incorporate important business and financial information about us that is not included in or delivered with this prospectus supplement and the accompanying prospectus. The information incorporated by reference is considered to be part of this prospectus supplement and the accompanying prospectus, except for any information superseded by information in this prospectus supplement and the accompanying prospectus. This prospectus supplement and the accompanying prospectus incorporate by reference the documents set forth below that have previously been filed with the SEC:

• Our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 23, 2023.

• The description of our common stock included in Exhibit 4.2 to our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 23, 2023, as well as any additional amendments or reports filed with the SEC for the purpose of updating such description.

We also incorporate by reference all documents that we subsequently file with the SEC after the filing of this prospectus supplement pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act and prior to the sale of all securities registered hereunder or termination of the registration statement. Nothing in this prospectus supplement shall be deemed to incorporate information furnished but not filed with the SEC.

You may request a free copy of any of the documents incorporated by reference in this prospectus by writing or telephoning us at the following address:

ENGAGESMART, INC.

30 BRAINTREE HILL OFFICE PARK, SUITE 101

BRAINTREE, MASSACHUSETTS 02184

Attention: Chief Legal Counsel

(781) 848-3733

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We will not, however, send exhibits to those documents, unless the exhibits are specifically incorporated by reference in those documents.

We make available free of charge on our website our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports, as soon as reasonably practicable after we electronically file or furnish such materials to the SEC. You may obtain a free copy of these reports on the Investor Relations section of our website, www.engagesmart.com.

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PROSPECTUS

ENGAGESMART, INC.

Common Stock

Preferred Stock

Debt Securities

Warrants

Purchase Contracts

Units

Common Stock

Offered by the Selling Securityholders

We may offer and sell the securities identified above, and the selling securityholders may offer and sell shares of common stock, in each case from time to time in one or more offerings. This prospectus provides you with a general description of the securities. We will not receive any proceeds from the sale of our common stock by the selling securityholders.

Each time we or any of the selling securityholders offer and sell securities, we or such selling securityholders will provide a supplement to this prospectus that contains specific information about the offering and, if applicable, the selling securityholders, as well as the amounts, prices and terms of the securities. The supplement may also add, update or change information contained in this prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement, together with the documents we incorporate by reference, before you invest in any of our securities.

We may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, dealers and agents, or directly to purchasers, or through a combination of these methods. In addition, the selling securityholders may offer and sell shares of our common stock from time to time, together or separately. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of Distribution” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities.

INVESTING IN OUR SECURITIES INVOLVES RISKS. SEE THE “RISK FACTORS” ON PAGE 5 OF THIS PROSPECTUS, INCLUDING THE RISK FACTORS IN THE DOCUMENTS INCORPORATED BY REFERENCE IN THIS PROSPECTUS, AND ANY SIMILAR SECTION CONTAINED IN THE APPLICABLE PROSPECTUS SUPPLEMENT CONCERNING FACTORS YOU SHOULD CONSIDER BEFORE INVESTING IN OUR SECURITIES.

Our common stock is listed on the New York Stock Exchange (the “NYSE”) under the symbol “ESMT.” On February 27, 2023, the last reported sale price of our common stock on the NYSE was $21.13 per share.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is February 28, 2023.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS	1
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS	2
WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE	3
PROSPECTUS SUMMARY	4
RISK FACTORS	5
USE OF PROCEEDS	6
DESCRIPTION OF CAPITAL STOCK	7
DESCRIPTION OF DEBT SECURITIES	14
DESCRIPTION OF OTHER SECURITIES	22
GLOBAL SECURITIES	23
SELLING SECURITYHOLDERS	27
PLAN OF DISTRIBUTION	28
LEGAL MATTERS	29
EXPERTS	29

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the U.S. Securities and Exchange Commission (the “SEC”) as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”), using a “shelf” registration process. By using a shelf registration statement, we may sell securities from time to time and in one or more offerings and the selling securityholders to be named in a supplement to this prospectus may, from time to time, sell shares of common stock from time to time in one or more offerings as described in this prospectus. Each time that we or the selling securityholders offer and sell securities, we or the selling securityholders will provide a prospectus supplement to this prospectus that contains specific information about the securities being offered and sold and the specific terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement or free writing prospectus may also add, update or change information contained in this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement or free writing prospectus, you should rely on the prospectus supplement or free writing prospectus, as applicable. Before purchasing any securities, you should carefully read both this prospectus and the applicable prospectus supplement (and any applicable free writing prospectuses), together with the additional information described under the heading “Where You Can Find More Information; Incorporation by Reference.”

Neither we, nor any agent, underwriter or dealer, or the selling securityholders, have authorized anyone to provide you with any information or to make any representations other than those contained in this prospectus, any applicable prospectus supplement or any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We, any agent, underwriter or dealer, and the selling securityholders take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We and the selling securityholders will not make an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus and the applicable prospectus supplement to this prospectus is accurate only as of the date on its respective cover, that the information appearing in any applicable free writing prospectus is accurate only as of the date of that free writing prospectus, and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates. This prospectus incorporates by reference, and any prospectus supplement or free writing prospectus may contain and incorporate by reference, market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. In addition, the market and industry data and forecasts that may be included or incorporated by reference in this prospectus, any prospectus supplement or any applicable free writing prospectus may involve estimates, assumptions and other risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” contained in this prospectus, the applicable prospectus supplement and any applicable free writing prospectus, and under similar headings in other documents that are incorporated by reference into this prospectus. Accordingly, investors should not place undue reliance on this information.

In connection with our initial public offering, EngageSmart, LLC converted into a Delaware corporation pursuant to a statutory conversion, and changed its name to EngageSmart, Inc. (the “Corporate Conversion”). When we refer to “EngageSmart,” “we,” “us,” “our,” “our company,” “Company,” and “our business” in this prospectus, we mean, prior to the Corporate Conversion, EngageSmart, LLC, and after the Corporate Conversion, EngageSmart, Inc., unless otherwise specified. When we refer to “you,” we mean the potential holders of the applicable series of securities.

1

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus contains forward-looking statements. We intend such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements other than statements of historical facts contained in this prospectus may be forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “targets,” “projects,” “contemplates,” “believes,” “estimates,” “forecasts,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. Forward-looking statements contained, or incorporated by reference, in this prospectus include, but are not limited to statements regarding our future results of operations and financial position, industry and business trends, equity compensation, business strategy, plans, market growth and our objectives for future operations, including related to digital adoption of our software solutions, customer acquisition strategies, investment in new products and enhancement of existing products, expansion into new verticals and the pursuit of select acquisitions and/or dispositions.

The forward-looking statements in this prospectus are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. Forward-looking statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to: risks related to our ability to sustain our rapid growth; our ability to manage our infrastructure to support future growth; risks related to the effectiveness of our risk management efforts to prevent fraudulent activities; risks related to our ability to attract new customers or convert trial customers into paying customers; risks related to our ability to introduce new features or services successfully and to make enhancements to our solutions; risks related to our customers renewing their contracts for our solutions with us and expanding their use of our solutions; risks related to any decline in our customer renewals or failure to convince our customers to broaden their use of solutions and related services; risks related to the net losses we have incurred on an annual basis, and anticipated increases in our operating expenses; our ability to adapt and respond effectively to rapidly changing technology, evolving industry standards and regulations, and changing business needs, requirements, or preferences; risks related to real or perceived errors, failures, or bugs in our solutions; our ability to face intense competition and to maintain or expand market share within our industry; our ability to establish, grow and maintain strategic partnerships; as well as the other important factors discussed in our most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K. The forward-looking statements in this prospectus are based upon information available to us as of the date of this prospectus, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

You should read this prospectus and the documents that we reference and have filed as exhibits to this prospectus with the understanding that our actual future results, performance and achievements may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements. These forward-looking statements speak only as of the date of this prospectus. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained in this prospectus, whether as a result of any new information, future events or otherwise.

2

WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE

Available Information

We file reports, proxy statements and other information with the SEC. The SEC maintains a web site that contains reports, proxy and information statements and other information about issuers, such as us, who file electronically with the SEC. The address of that website is http://www.sec.gov.

Our web site address is www.engagesmart.com. The information on our web site, however, is not, and should not be deemed to be, a part of this prospectus.

This prospectus and any prospectus supplement are part of a registration statement that we filed with the SEC and do not contain all of the information in the registration statement. The full registration statement may be obtained from the SEC or us, as provided below. Forms of the indenture and other documents establishing the terms of the offered securities are or may be filed as exhibits to the registration statement or documents incorporated by reference in the registration statement. Statements in this prospectus or any prospectus supplement about these documents are summaries and each statement is qualified in all respects by reference to the document to which it refers. You should refer to the actual documents for a more complete description of the relevant matters. You may access a copy of the registration statement through the SEC’s website, as provided above.

Incorporation by Reference

The SEC’s rules allow us to “incorporate by reference” information into this prospectus, which means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus, and subsequent information that we file with the SEC will automatically update and supersede that information. Any statement contained in this prospectus or a previously filed document incorporated by reference will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or a subsequently filed document incorporated by reference modifies or replaces that statement.

This prospectus and any accompanying prospectus supplement incorporate by reference the documents set forth below that have previously been filed with the SEC:

• Our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 23, 2023.

• The description of our common stock incorporated by reference in our registration statement on Form 8-A (File No. 001-40835), dated September 23, 2021, filed with the SEC on September  23, 2021, as updated in Exhibit 4.2 to our Annual Report for the year ended December 31, 2022, as well as any additional amendments or reports filed with the SEC for the purpose of updating such description.

All reports and other documents we subsequently file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act in this prospectus, until all offerings under the registration statement of which this prospectus is a part are completed or terminated but excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference into this prospectus and deemed to be part of this prospectus from the date of the filing of such reports and documents.

You may request a free copy of any of the documents incorporated by reference in this prospectus by writing or telephoning us at the following address:

ENGAGESMART, INC.

30 BRAINTREE HILL OFFICE PARK, SUITE 101

BRAINTREE, MASSACHUSETTS 02184

(781) 848-3733

Exhibits to the filings will not be sent, however, unless those exhibits have specifically been incorporated by reference in this prospectus or any accompanying prospectus supplement.

3

PROSPECTUS SUMMARY

This summary highlights selected information that is presented in greater detail elsewhere, or incorporated by reference, in this prospectus. It does not contain all of the information that may be important to you and your investment decision. Before investing in our securities, you should carefully read this entire prospectus, including the matters set forth under the section of this prospectus captioned “Risk Factors” and the financial statements and related notes and other information that we incorporate by reference herein, including our Annual Report on Form 10- K.

Overview

We are a leading provider of vertically tailored customer engagement software and integrated payments solutions. At EngageSmart, our mission is to simplify customer and client engagement to allow our customers to focus resources on initiatives that improve their businesses and better serve their communities. We offer single instance, multi-tenant, true Software-as-a-Service vertical solutions that are designed to simplify our customers’ engagement with their clients by driving digital adoption and self-service.

Corporate Information

We were initially formed as Hancock Parent, LLC, a Delaware limited liability company, on December 7, 2018. On January 24, 2020, Hancock Parent, LLC changed its name to EngageSmart, LLC. Prior to the closing of our initial public offering on September 27, 2021, EngageSmart, LLC converted into a Delaware corporation pursuant to a statutory conversion and changed its name to EngageSmart, Inc.

Our principal executive offices are located at 30 Braintree Hill Office Park, Suite 101, Braintree, Massachusetts 02184, and our telephone number is (781) 848-3733. Our corporate website address is www.engagesmart.com. Information contained on, or accessible through, our website shall not be deemed incorporated into and is not a part of this prospectus or the registration statement of which it forms a part. We have included our website in this prospectus solely as an inactive textual reference.

4

RISK FACTORS

Investment in any securities offered pursuant to this prospectus and the applicable prospectus supplement involves risks. Before deciding whether to invest in our securities, you should carefully consider the risk factors incorporated by reference to our most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K, and all other information contained or incorporated by reference into this prospectus, as updated by our subsequent filings under the Exchange Act, and the risk factors and other information contained in the applicable prospectus supplement and any applicable free writing prospectus. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our securities to decline, resulting in a loss of all or part of your investment. Please also carefully read the section entitled “Special Note Regarding Forward-Looking Statements” included in this prospectus, in our most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K.

5

USE OF PROCEEDS

We intend to use the net proceeds from the sale of the securities as set forth in the applicable prospectus supplement. We will not receive any of the proceeds from the sale of common stock being offered by any of the selling securityholders.

6

DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock is not complete and may not contain all the information you should consider before investing in our capital stock. This description is summarized from, and qualified in its entirety by reference to, our amended and restated certificate of incorporation (the “Amended Charter”) and bylaws (“Bylaws”), which have been publicly filed with the SEC. See “Where You Can Find More Information; Incorporation by Reference.”

Our authorized capital stock consists of 650,000,000 shares of common stock, par value $0.001 per share, and 10,000,000 shares of preferred stock, par value $0.001 per share.

Common Stock

Dividend Rights

Holders of shares of our common stock are entitled to receive dividends when, as and if declared by our board of directors out of funds legally available therefor, subject to any statutory or contractual restrictions on the payment of dividends and to any restrictions on the payment of dividends imposed by the terms of any outstanding stock. Under Delaware law, we can only pay dividends either out of “surplus” or out of the current or the immediately preceding year’s net profits. Surplus is defined as the excess, if any, at any given time, of the total assets of a corporation over its total liabilities and statutory capital. The value of a corporation’s assets can be measured in a number of ways and may not necessarily equal their book value.

Applicable insurance laws restrict the ability of our insurance subsidiaries to declare stockholder dividends and require insurance companies to maintain specified levels of statutory capital and surplus. Insurance regulators have broad powers to prevent reduction of statutory surplus to inadequate levels, and there is no assurance that dividends of the maximum amounts calculated under any applicable formula would be permitted. State insurance regulatory authorities that have jurisdiction over the payment of dividends by our insurance subsidiaries may in the future adopt statutory provisions more restrictive than those currently in effect.

We currently intend to retain any future earnings and do not expect to pay any dividends in the foreseeable future.

Voting Rights

Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders. The holders of our common stock vote together as a single class, unless otherwise required by law. The holders of our common stock do not have cumulative voting rights in the election of directors.

Our Amended Charter provides for a classified board of directors consisting of three classes of approximately equal size, each serving staggered three-year terms. If the number of directors is changed, any increase or decrease shall be apportioned among the classes by the board of directors so as to maintain the number of directors in each class as nearly equal as possible, and any additional director of any class elected to fill a vacancy resulting from an increase in such class shall hold office for a term that shall coincide with the remaining term of that class. In no case will a decrease in the number of directors shorten the term of any incumbent director.

No Preemptive or Similar Rights

Holders of our common stock do not have preemptive, subscription, redemption, or conversion rights. There are no redemption or sinking fund provisions applicable to our common stock. The rights, preferences and privileges of the holders of our common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of our preferred stock that we may designate in the future.

7

Right to Receive Liquidation Distributions

In the event of our liquidation, dissolution, or winding-up, the assets legally available for distribution to our stockholders would be distributable ratably among the holders of our common stock and any participating preferred stock outstanding at that time, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights of and the payment of liquidation preferences, if any, on any outstanding shares of preferred stock.

Fully Paid and Non-Assessable

All shares of our common stock outstanding are fully paid and non-assessable.

Preferred Stock

Under our Amended Charter, our board of directors is authorized to direct us to issue shares of preferred stock in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges, and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges, and liquidation preferences, of each series of preferred stock, including, without limitation:

• the designation of the series;

• the number of shares of the series, which our board of directors may, except where otherwise provided in the preferred stock designation, increase (but not above the total number of authorized shares of the class) or decrease (but not below the number of shares then outstanding);

• whether dividends, if any, will be cumulative or non-cumulative and the dividend rate of the series;

• the dates at which dividends, if any, will be payable;

• the redemption or repurchase rights and price or prices, if any, for shares of the series;

• the terms and amounts of any sinking fund provided for the purchase or redemption of shares of the series;

• the amounts payable on shares of the series in the event of any voluntary or involuntary liquidation, dissolution, or winding-up of our affairs;

• whether the shares of the series will be convertible into shares of any other class or series, or any other security, of us or any other entity, and, if so, the specification of the other class or series or other security, the conversion price or prices, or rate or rates, any rate adjustments, the date or dates as of which the shares will be convertible and all other terms and conditions upon which the conversion may be made;

• restrictions on the issuance of shares of the same series or of any other class or series; and

• the voting rights, if any, of the holders of the series.

We could issue a series of preferred stock that could, depending on the terms of the series, impede or discourage an acquisition attempt or other transaction that some, or a majority, of the holders of our common stock might believe to be in their best interests or in which the holders of our common stock might receive a premium over the market price of the shares of our common stock. Additionally, the issuance of preferred stock may adversely affect the rights of holders of our common stock by restricting dividends on our common stock, diluting the voting power of our common stock or subordinating the liquidation rights of our common stock. As a result of these or other factors, the issuance of preferred stock could have an adverse impact on the market price of our common stock. We have no current plan for the issuance of any shares of preferred stock.

8

Anti-Takeover Effects of Delaware Law

The Delaware General Corporation Law (“DGCL”) and our Amended Charter and Bylaws contain provisions that may delay, defer or discourage another party from acquiring control of us. We expect that these provisions, which are summarized below, will discourage coercive takeover practices or inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors, which we believe may result in an improvement of the terms of any such acquisition in favor of our stockholders. However, they also give our board of directors the power to discourage acquisitions that some stockholders may favor.

Classified Board of Directors

Our Amended Charter provides that our board of directors be classified into three classes of directors, each of which will hold office for a three-year term. In addition, directors may only be removed from the board of directors for cause. The existence of a classified board could delay a potential acquirer from obtaining majority control of our board of directors, and the prospect of that delay might deter a potential acquirer.

Authorized but Unissued Shares

The authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval, subject to any limitations imposed by the listing standards of the NYSE. These additional shares may be used for a variety of corporate finance transactions, acquisitions and employee benefit plans. The existence of authorized but unissued and unreserved common stock and preferred stock could make more difficult or discourage an attempt to obtain control of us by means of a proxy contest, tender offer, merger or otherwise.

Advance Notice Requirements for Stockholder Proposals and Director Nominations

Our Bylaws provide for advance-notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of our board of directors or a committee of our board of directors, and provided, however, that at any time prior to the first date General Atlantic, L.P. (“General Atlantic”) and its affiliated companies cease to beneficially own in aggregate at least 40% of the shares entitled to vote of the Company (the “Stockholder Consent Trigger Date”), such advance notice procedure will not apply to General Atlantic. Stockholders at an annual meeting will only be able to consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of our board of directors or by a stockholder who was a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has given our secretary timely written notice, in proper form, of the stockholder’s intention to bring that business before the meeting. Although the Bylaws do not give our board of directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, the Bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed or may discourage or deter a potential acquirer from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of the Company. These provisions do not apply to nominations by General Atlantic or Summit Partners pursuant to the stockholders agreement, which is filed with the SEC.

Stockholder Action by Written Consent; Special Meetings of Stockholders

Our Amended Charter precludes stockholder action by written consent at any time from and after the Stockholder Consent Trigger Date. Our Amended Charter and Bylaws also provide that, except as required by law, special meetings of our stockholders may be called at any time only by or at the direction of our board of directors or the chairman of our board of directors provided, however, at any time prior to the Stockholder Consent Trigger Date, special meetings of our stockholders shall also be called by our board of directors or the

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chairman of our board of directors at the request of General Atlantic. Our Bylaws prohibit the conduct of any business at a special meeting other than as specified in the notice for such meeting. These provisions may have the effect of deferring, delaying or discouraging hostile takeovers, or changes in control or management of the Company.

No Cumulative Voting

The DGCL provides that stockholders are not entitled to cumulate votes in the election of directors unless a corporation’s certificate of incorporation provides otherwise. Our Amended Charter does not provide for cumulative voting.

Amendment of Amended Charter or Bylaws

Our Amended Charter requires the approval of, prior to the Stockholder Consent Trigger Date, at least a majority of the voting power of all outstanding shares entitled to vote, and on or after the Stockholder Consent Trigger Date, at least 66 2/3% of the shares entitled to vote at an election of directors to adopt, amend or repeal certain provisions of our Amended Charter, including anti-takeover provisions related to our classified board of directors, voting in the election of directors, rights to fill board vacancies, the ability of our board of directors to alter our Bylaws without stockholder approval, the inability of stockholders to act by written consent, the exclusive right of the board of directors to call special meetings of stockholders, and choice of forum, and the required stockholder vote to amend the foregoing provisions of our Amended Charter.

The foregoing provisions of our Amended Charter and Bylaws could discourage potential acquisition proposals and could delay or prevent a change in control. These provisions are intended to enhance the likelihood of continuity and stability in the composition of our board of directors and in the policies formulated by our board of directors and to discourage certain types of transactions that may involve an actual or threatened change of control. These provisions are designed to reduce our vulnerability to an unsolicited acquisition proposal. The provisions also are intended to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and, as a consequence, they also may inhibit fluctuations in the market price of our shares of common stock that could result from actual or rumored takeover attempts. Such provisions also may have the effect of preventing changes in our management or delaying or preventing a transaction that might benefit you or other minority stockholders.

Issuance of Undesignated Preferred Stock

Our board of directors has the authority, without further action by our stockholders, to issue up to 10,000,000 shares of undesignated preferred stock with rights and preferences, including voting rights, designated from time to time by our board of directors. The existence of authorized but unissued shares of preferred stock enables our board of directors to render more difficult or to discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest or other means.

Business Combinations

We are not subject to the provisions of Section 203 of the DGCL. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that the person becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions: (1) before the stockholder became an interested

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stockholder, the board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder; (2) upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances; or (3) at or after the time the stockholder became an interested stockholder, the business combination was approved by the board of directors and authorized at an annual or special meeting of the stockholders by the affirmative vote of at least two-thirds of the outstanding voting stock which is not owned by the interested stockholder.

A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its certificate of incorporation or bylaws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares.

We have opted out of Section 203, our Amended Charter contains similar provisions providing that we may not engage in certain “business combinations” with any “interested stockholder” for a three-year period following the time that the stockholder became an interested stockholder, unless:

• prior to such time, our board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

• upon consummation of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of our voting stock outstanding at the time the transaction commenced, excluding certain shares; or

• at or subsequent to that time, the business combination is approved by our board of directors and by the affirmative vote of holders of at least 66 2/3% of our outstanding voting stock that is not owned by the interested stockholder.

Under certain circumstances, this provision will make it more difficult for a person who would be an “interested stockholder” to effect various business combinations with the Company for a three-year period. This provision may encourage companies interested in acquiring the Company to negotiate in advance with our board of directors because the stockholder approval requirement would be avoided if our board of directors approves either the business combination or the transaction which results in the stockholder becoming an interested stockholder. These provisions also may have the effect of preventing changes in our board of directors and may make it more difficult to accomplish transactions which stockholders may otherwise deem to be in their best interests.

Our Amended Charter provides that General Atlantic, and any of their direct or indirect transferees and any group as to which such persons are a party, do not constitute “interested stockholders” for purposes of this provision.

Exclusive Venue

Our Amended Charter requires, to the fullest extent permitted by law, that (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers, employees or stockholders to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the DGCL or of our Amended Charter or our Bylaws or as to which the DGCL confers jurisdiction on the Court of Chancery of the State of Delaware, or (iv) any action asserting a claim governed by the internal affairs doctrine will have to be brought only in the Court of Chancery in the State of Delaware; provided that, the exclusive forum provision will not apply to suits brought to enforce any liability or duty created by the Securities Act, the Exchange Act, or to any claim for which there is exclusive or concurrent federal and state jurisdiction. Our Amended Charter also provides that unless we consent in writing to the

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selection of an alternative forum, the U.S. federal district courts shall be the exclusive forum for the resolution of any claims arising under the Securities Act. Any person or entity purchasing or otherwise acquiring any interest in our securities shall be deemed to have notice of and consented to this provision. Although we believe this provision benefits us by providing increased consistency in the application of Delaware law in the types of lawsuits to which it applies, the provision may have the effect of discouraging lawsuits against our directors and officers.

Limitations on Liability and Indemnification of Officers and Directors

The DGCL authorizes corporations to limit or eliminate the personal liability of directors to corporations and their stockholders for monetary damages for breaches of directors’ fiduciary duties, subject to certain exceptions. Our Amended Charter includes a provision that eliminates the personal liability of directors for monetary damages to the corporation or its stockholders for any breach of fiduciary duty as a director, except to the extent such exemption from liability or limitation thereof is not permitted under the DGCL. The effect of these provisions is to eliminate the rights of us and our stockholders, through stockholders’ derivative suits on our behalf, to recover monetary damages from a director for breach of fiduciary duty as a director, including breaches resulting from grossly negligent behavior. However, exculpation does not apply to any breaches of the director’s duty of loyalty, any acts or omissions not in good faith or that involve intentional misconduct or knowing violation of law, any authorization of dividends or stock redemptions or repurchases paid or made in violation of the DGCL, or for any transaction from which the director derived an improper personal benefit.

Our Bylaws generally provide that we must indemnify and advance expenses to our directors and officers to the fullest extent authorized by the DGCL. We are also expressly authorized to carry directors’ and officers’ liability insurance providing indemnification for our directors, officers, and certain employees for some liabilities. We believe that these indemnification and advancement provisions and insurance are useful to attract and retain qualified directors and executive officers.

The limitation of liability, indemnification, and advancement provisions in our Amended Charter and Bylaws may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duty. These provisions also may have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit us and our stockholders. In addition, your investment may be adversely affected to the extent we pay the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions.

Indemnification Agreements

We have entered into indemnification agreements with each of our directors and executive officers. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors or executive officers, we have been informed that in the opinion of the SEC such indemnification is against public policy and is therefore unenforceable.

Dissenters’ Right of Appraisal and Payment

Under the DGCL, with certain exceptions, our stockholders will have appraisal rights in connection with a merger or consolidation of EngageSmart, Inc. Pursuant to the DGCL, stockholders who properly request and perfect appraisal rights in connection with such merger or consolidation will have the right to receive payment of the fair value of their shares as determined by the Court of Chancery in the State of Delaware.

Stockholders’ Derivative Actions

Under the DGCL, any of our stockholders may bring an action in our name to procure a judgment in our favor, also known as a derivative action, provided that the stockholder bringing the action is a holder of our

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shares at the time of the transaction to which the action relates or such stockholder’s shares thereafter devolved by operation of law and such suit is brought in the Court of Chancery in the State of Delaware. See “—Exclusive Venue” above.

Listing

Our common stock is listed on the NYSE under the symbol “ESMT.”

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

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DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplement or free writing prospectus, summarizes certain general terms and provisions of the debt securities that we may offer under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the supplement to what extent the general terms and provisions described in this prospectus apply to a particular series of debt securities.

We may issue debt securities either separately, or together with, or upon the conversion or exercise of or in exchange for, other securities described in this prospectus. Debt securities may be our senior, senior subordinated or subordinated obligations and, unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations and may be issued in one or more series.

The debt securities will be issued under an indenture between us and a trustee named in a prospectus supplement. We have summarized select portions of the indenture below. The summary is not complete. The form of the indenture has been filed as an exhibit to the registration statement and you should read the indenture for provisions that may be important to you. In the summary below, we have included references to the section numbers of the indenture so that you can easily locate these provisions. Capitalized terms used in the summary and not defined herein have the meanings specified in the indenture.

As used in this section only, “EngageSmart,” “we,” “our” or “us” refer to EngageSmart, Inc. excluding our subsidiaries, unless expressly stated or the context otherwise requires.

General

The terms of each series of debt securities will be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in a resolution of our board of directors, in an officer’s certificate or by a supplemental indenture. (Section 2.2) The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series (including any pricing supplement or term sheet).

We can issue an unlimited amount of debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium, or at a discount. (Section 2.1) We will set forth in a prospectus supplement (including any pricing supplement or term sheet) relating to any series of debt securities being offered, the aggregate principal amount and the following terms of the debt securities, if applicable:

• the title and ranking of the debt securities (including the terms of any subordination provisions);

• the price or prices (expressed as a percentage of the principal amount) at which we will sell the debt securities;

• any limit on the aggregate principal amount of the debt securities;

• the date or dates on which the principal of the securities of the series is payable;

• the rate or rates (which may be fixed or variable) per annum or the method used to determine the rate or rates (including any commodity, commodity index, stock exchange index or financial index) at which the debt securities will bear interest, the date or dates from which interest will accrue, the date or dates on which interest will commence and be payable and any regular record date for the interest payable on any interest payment date;

• the place or places where principal of, and interest, if any, on the debt securities will be payable (and the method of such payment), where the securities of such series may be surrendered for registration of transfer or exchange, and where notices and demands to us in respect of the debt securities may be delivered;

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• the period or periods within which, the price or prices at which and the terms and conditions upon which we may redeem the debt securities;

• any obligation we have to redeem or purchase the debt securities pursuant to any sinking fund or analogous provisions or at the option of a holder of debt securities and the period or periods within which, the price or prices at which and in the terms and conditions upon which securities of the series shall be redeemed or purchased, in whole or in part, pursuant to such obligation;

• the dates on which and the price or prices at which we will repurchase debt securities at the option of the holders of debt securities and other detailed terms and provisions of these repurchase obligations;

• the denominations in which the debt securities will be issued, if other than denominations of $1,000 and any integral multiple thereof;

• whether the debt securities will be issued in the form of certificated debt securities or global debt securities;

• the portion of principal amount of the debt securities payable upon declaration of acceleration of the maturity date, if other than the principal amount;

• the currency of denomination of the debt securities, which may be United States Dollars or any foreign currency, and if such currency of denomination is a composite currency, the agency or organization, if any, responsible for overseeing such composite currency;

• the designation of the currency, currencies or currency units in which payment of principal of, premium and interest on the debt securities will be made;

• if payments of principal of, premium or interest on the debt securities will be made in one or more currencies or currency units other than that or those in which the debt securities are denominated, the manner in which the exchange rate with respect to these payments will be determined;

• the manner in which the amounts of payment of principal of, premium, if any, or interest on the debt securities will be determined, if these amounts may be determined by reference to an index based on a currency or currencies or by reference to a commodity, commodity index, stock exchange index or financial index;

• any provisions relating to any security provided for the debt securities;

• any addition to, deletion of or change in the Events of Default described in this prospectus or in the indenture with respect to the debt securities and any change in the acceleration provisions described in this prospectus or in the indenture with respect to the debt securities;

• any addition to, deletion of or change in the covenants described in this prospectus or in the indenture with respect to the debt securities;

• any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents with respect to the debt securities;

• the provisions, if any, relating to conversion or exchange of any debt securities of such series, including if applicable, the conversion or exchange price and period, provisions as to whether conversion or exchange will be mandatory, the events requiring an adjustment of the conversion or exchange price and provisions affecting conversion or exchange;

• any other terms of the debt securities, which may supplement, modify or delete any provision of the indenture as it applies to that series, including any terms that may be required under applicable law or regulations or advisable in connection with the marketing of the securities; and

• whether any of our direct or indirect subsidiaries will guarantee the debt securities of that series, including the terms of subordination, if any, of such guarantees. (Section 2.2)

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We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the material federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company (the “Depositary”), or a nominee of the Depositary (we will refer to any debt security represented by a global debt security as a “book-entry debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a “certificated debt security”) as set forth in the applicable prospectus supplement. Except as set forth under the heading “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. (Section 2.4) No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange. (Section 2.7)

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the Depositary, and registered in the name of the Depositary or a nominee of the Depositary. Please see “Global Securities.”

Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities. (Article IV)

No Protection in the Event of a Change of Control

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions which may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) which could adversely affect holders of debt securities.

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Consolidation, Merger and Sale of Assets

We may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to any person (a “successor person”) unless:

we are the surviving entity or the successor person (if other than EngageSmart) is a corporation, partnership, trust or other entity organized and validly existing under the laws Delaware and expressly assumes our obligations on the debt securities and under the indenture; and

immediately after giving effect to the transaction, no Default or Event of Default, shall have occurred and be continuing.

Notwithstanding the above, any of our subsidiaries may consolidate with, merge into or transfer all or part of its properties to us. (Section 5.1)

Events of Default

“Event of Default” means with respect to any series of debt securities, any of the following:

• default in the payment of any interest upon any debt security of that series when it becomes due and payable, and continuance of such default for a period of 30 days (unless the entire amount of the payment is deposited by us with the trustee or with a paying agent prior to the expiration of the 30-day period);

• default in the payment of principal of any security of that series at its maturity;

• default in the performance or breach of any other covenant or warranty by us in the indenture (other than a covenant or warranty that has been included in the indenture solely for the benefit of a series of debt securities other than that series), which default continues uncured for a period of 60 days after we receive written notice from the trustee or EngageSmart and the trustee receive written notice from the holders of not less than 25% in principal amount of the outstanding debt securities of that series as provided in the indenture;

• certain voluntary or involuntary events of bankruptcy, insolvency or reorganization of EngageSmart;

• any other Event of Default provided with respect to debt securities of that series that is described in the applicable prospectus supplement. (Section 6.1)

No Event of Default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an Event of Default with respect to any other series of debt securities. (Section 6.1) The occurrence of certain Events of Default or an acceleration under the indenture may constitute an event of default under certain indebtedness of ours or our subsidiaries outstanding from time to time.

We will provide the trustee written notice of any Default or Event of Default within 30 days of becoming aware of the occurrence of such Default or Event of Default, which notice will describe in reasonable detail the status of such Default or Event of Default and what action we are taking or propose to take in respect thereof. (Section 6.1)

If an Event of Default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal of (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an Event of Default resulting from certain events of

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bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if all Events of Default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. (Section 6.2) We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an Event of Default.

The indenture provides that the trustee may refuse to perform any duty or exercise any of its rights or powers under the indenture unless the trustee receives indemnity satisfactory to it against any cost, liability or expense which might be incurred by it in performing such duty or exercising such right or power. (Section 7.1(e)) Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series. (Section 6.12)

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

• that holder has previously given to the trustee written notice of a continuing Event of Default with respect to debt securities of that series; and

• the holders of not less than 25% in principal amount of the outstanding debt securities of that series have made written request, and offered indemnity or security satisfactory to the trustee, to the trustee to institute the proceeding as trustee, and the trustee has not received from the holders of not less than a majority in principal amount of the outstanding debt securities of that series a direction inconsistent with that request and has failed to institute the proceeding within 60 days. (Section 6.7)

Notwithstanding any other provision in the indenture, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, premium and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment. (Section 6.8)

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. (Section 4.3) If a Default or Event of Default occurs and is continuing with respect to the securities of any series and if it is known to a responsible officer of the trustee, the trustee shall mail to each securityholder of the securities of that series notice of a Default or Event of Default within 90 days after it occurs or, if later, after a responsible officer of the trustee has knowledge of such Default or Event of Default. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any Default or Event of Default (except in payment on any debt securities of that series) with respect to debt securities of that series if the trustee determines in good faith that withholding notice is in the interest of the holders of those debt securities. (Section 7.5)

Modification and Waiver

We and the trustee may modify, amend or supplement the indenture or the debt securities of any series without the consent of any holder of any debt security:

• to cure any ambiguity, defect or inconsistency;

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• to comply with covenants in the indenture described above under the heading “Consolidation, Merger and Sale of Assets”;

• to provide for uncertificated securities in addition to or in place of certificated securities;

• to add guarantees with respect to debt securities of any series or secure debt securities of any series;

• to surrender any of our rights or powers under the indenture;

• to add covenants or events of default for the benefit of the holders of debt securities of any series;

• to comply with the applicable procedures of the applicable depositary;

• to make any change that does not adversely affect the rights of any holder of debt securities;

• to provide for the issuance of and establish the form and terms and conditions of debt securities of any series as permitted by the indenture;

• to effect the appointment of a successor trustee with respect to the debt securities of any series and to add to or change any of the provisions of the indenture to provide for or facilitate administration by more than one trustee; or

• to comply with requirements of the SEC in order to effect or maintain the qualification of the indenture under the Trust Indenture Act. (Section 9.1)

We may also modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We may not make any modification or amendment without the consent of the holders of each affected debt security then outstanding if that amendment will:

• reduce the amount of debt securities whose holders must consent to an amendment, supplement or waiver;

• reduce the rate of or extend the time for payment of interest (including default interest) on any debt security;

• reduce the principal of or premium on or change the fixed maturity of any debt security or reduce the amount of, or postpone the date fixed for, the payment of any sinking fund or analogous obligation with respect to any series of debt securities;

• reduce the principal amount of discount securities payable upon acceleration of maturity;

• waive a default in the payment of the principal of, premium or interest on any debt security (except a rescission of acceleration of the debt securities of any series by the holders of at least a majority in aggregate principal amount of the then outstanding debt securities of that series and a waiver of the payment default that resulted from such acceleration);

• make the principal of or premium or interest on any debt security payable in currency other than that stated in the debt security;

• make any change to certain provisions of the indenture relating to, among other things, the right of holders of debt securities to receive payment of the principal of, premium and interest on those debt securities and to institute suit for the enforcement of any such payment and to waivers or amendments; or

• waive a redemption payment with respect to any debt security. (Section 9.3)

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. (Section 9.2) The holders of a majority in principal amount of

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the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration. (Section 6.13)

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (subject to certain exceptions). We will be so discharged upon the irrevocable deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. Dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money or U.S. government obligations in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable United States federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred. (Section 8.3)

Defeasance of Certain Covenants. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

• we may omit to comply with the covenant described under the heading “Consolidation, Merger and Sale of Assets” and certain other covenants set forth in the indenture, as well as any additional covenants which may be set forth in the applicable prospectus supplement; and

• any omission to comply with those covenants will not constitute a Default or an Event of Default with respect to the debt securities of that series (“covenant defeasance”).

The conditions include:

• depositing with the trustee money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. Dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal of, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities; and

• delivering to the trustee an opinion of counsel to the effect that the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit and related covenant defeasance and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit and related covenant defeasance had not occurred. (Section 8.4)

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No Personal Liability of Directors, Officers, Employees or Securityholders

None of our past, present or future directors, officers, employees or securityholders, as such, will have any liability for any of our obligations under the debt securities or the indenture or for any claim based on, or in respect or by reason of, such obligations or their creation. By accepting a debt security, each holder waives and releases all such liability. This waiver and release is part of the consideration for the issue of the debt securities. However, this waiver and release may not be effective to waive liabilities under U.S. federal securities laws, and it is the view of the SEC that such a waiver is against public policy.

Governing Law

The indenture and the debt securities, including any claim or controversy arising out of or relating to the indenture or the securities, will be governed by the laws of the State of New York.

The indenture will provide that we, the trustee and the holders of the debt securities (by their acceptance of the debt securities) irrevocably waive, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to the indenture, the debt securities or the transactions contemplated thereby.

The indenture will provide that any legal suit, action or proceeding arising out of or based upon the indenture or the transactions contemplated thereby may be instituted in the federal courts of the United States of America located in the City of New York or the courts of the State of New York in each case located in the City of New York, and we, the trustee and the holder of the debt securities (by their acceptance of the debt securities) irrevocably submit to the non-exclusive jurisdiction of such courts in any such suit, action or proceeding. The indenture will further provide that service of any process, summons, notice or document by mail (to the extent allowed under any applicable statute or rule of court) to such party’s address set forth in the indenture will be effective service of process for any suit, action or other proceeding brought in any such court. The indenture will further provide that we, the trustee and the holders of the debt securities (by their acceptance of the debt securities) irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the courts specified above and irrevocably and unconditionally waive and agree not to plead or claim any such suit, action or other proceeding has been brought in an inconvenient forum. (Section 10.10)

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DESCRIPTION OF OTHER SECURITIES

We will set forth in the applicable prospectus supplement a description of any warrants, purchase contracts or units issued by us that may be offered and sold pursuant to this prospectus.

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GLOBAL SECURITIES

Book-Entry, Delivery and Form

Unless we indicate differently in any applicable prospectus supplement or free writing prospectus, the securities initially will be issued in book-entry form and represented by one or more global notes or global securities, or, collectively, global securities. The global securities will be deposited with, or on behalf of, The Depository Trust Company, New York, New York, as depositary (“DTC”), and registered in the name of Cede & Co., the nominee of DTC. Unless and until it is exchanged for individual certificates evidencing securities under the limited circumstances described below, a global security may not be transferred except as a whole by the depositary to its nominee or by the nominee to the depositary, or by the depositary or its nominee to a successor depositary or to a nominee of the successor depositary.

DTC has advised us that it is:

• a limited-purpose trust company organized under the New York Banking Law;

• a “banking organization” within the meaning of the New York Banking Law;

• a member of the Federal Reserve System;

• a “clearing corporation” within the meaning of the New York Uniform Commercial Code; and

• a “clearing agency” registered pursuant to the provisions of Section 17A of the Exchange Act.

DTC holds securities that its participants deposit with DTC. DTC also facilitates the settlement among its participants of securities transactions, such as transfers and pledges, in deposited securities through electronic computerized book-entry changes in participants’ accounts, thereby eliminating the need for physical movement of securities certificates. “Direct participants” in DTC include securities brokers and dealers, including underwriters, banks, trust companies, clearing corporations and other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation (“DTCC”). DTCC is the holding company for DTC, National Securities Clearing Corporation and Fixed Income Clearing Corporation, all of which are registered clearing agencies. DTCC is owned by the users of its regulated subsidiaries. Access to the DTC system is also available to others, which we sometimes refer to as indirect participants, that clear through or maintain a custodial relationship with a direct participant, either directly or indirectly. The rules applicable to DTC and its participants are on file with the SEC.

Purchases of securities under the DTC system must be made by or through direct participants, which will receive a credit for the securities on DTC’s records. The ownership interest of the actual purchaser of a security, which we sometimes refer to as a beneficial owner, is in turn recorded on the direct and indirect participants’ records. Beneficial owners of securities will not receive written confirmation from DTC of their purchases. However, beneficial owners are expected to receive written confirmations providing details of their transactions, as well as periodic statements of their holdings, from the direct or indirect participants through which they purchased securities. Transfers of ownership interests in global securities are to be accomplished by entries made on the books of participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in the global securities, except under the limited circumstances described below.

To facilitate subsequent transfers, all global securities deposited by direct participants with DTC will be registered in the name of DTC’s partnership nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC. The deposit of securities with DTC and their registration in the name of Cede & Co. or such other nominee will not change the beneficial ownership of the securities. DTC has no knowledge of the actual beneficial owners of the securities. DTC’s records reflect only the identity of the direct participants to whose accounts the securities are credited, which may or may not be the beneficial owners. The participants are responsible for keeping account of their holdings on behalf of their customers.

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So long as the securities are in book-entry form, you will receive payments and may transfer securities only through the facilities of the depositary and its direct and indirect participants. We will maintain an office or agency in the location specified in the prospectus supplement for the applicable securities, where notices and demands in respect of the securities and the indenture may be delivered to us and where certificated securities may be surrendered for payment, registration of transfer or exchange.

Conveyance of notices and other communications by DTC to direct participants, by direct participants to indirect participants and by direct participants and indirect participants to beneficial owners will be governed by arrangements among them, subject to any legal requirements in effect from time to time.

Redemption notices will be sent to DTC. If less than all of the securities of a particular series are being redeemed, DTC’s practice is to determine by lot the amount of the interest of each direct participant in the securities of such series to be redeemed.

Neither DTC nor Cede & Co. (or such other DTC nominee) will consent or vote with respect to the securities. Under its usual procedures, DTC will mail an omnibus proxy to us as soon as possible after the record date. The omnibus proxy assigns the consenting or voting rights of Cede & Co. to those direct participants to whose accounts the securities of such series are credited on the record date, identified in a listing attached to the omnibus proxy.

So long as securities are in book-entry form, we will make payments on those securities to the depositary or its nominee, as the registered owner of such securities, by wire transfer of immediately available funds. If securities are issued in definitive certificated form under the limited circumstances described below and unless if otherwise provided in the description of the applicable securities herein or in the applicable prospectus supplement, we will have the option of making payments by check mailed to the addresses of the persons entitled to payment or by wire transfer to bank accounts in the United States designated in writing to the applicable trustee or other designated party at least 15 days before the applicable payment date by the persons entitled to payment, unless a shorter period is satisfactory to the applicable trustee or other designated party.

Redemption proceeds, distributions and dividend payments on the securities will be made to Cede & Co., or such other nominee as may be requested by an authorized representative of DTC. DTC’s practice is to credit direct participants’ accounts upon DTC’s receipt of funds and corresponding detail information from us on the payment date in accordance with their respective holdings shown on DTC records. Payments by participants to beneficial owners will be governed by standing instructions and customary practices, as is the case with securities held for the account of customers in bearer form or registered in “street name.” Those payments will be the responsibility of participants and not of DTC or us, subject to any statutory or regulatory requirements in effect from time to time. Payment of redemption proceeds, distributions and dividend payments to Cede & Co., or such other nominee as may be requested by an authorized representative of DTC, is our responsibility, disbursement of payments to direct participants is the responsibility of DTC, and disbursement of payments to the beneficial owners is the responsibility of direct and indirect participants.

Except under the limited circumstances described below, purchasers of securities will not be entitled to have securities registered in their names and will not receive physical delivery of securities. Accordingly, each beneficial owner must rely on the procedures of DTC and its participants to exercise any rights under the securities and the indenture.

The laws of some jurisdictions may require that some purchasers of securities take physical delivery of securities in definitive form. Those laws may impair the ability to transfer or pledge beneficial interests in securities.

DTC may discontinue providing its services as securities depositary with respect to the securities at any time by giving reasonable notice to us. Under such circumstances, in the event that a successor depositary is not obtained, securities certificates are required to be printed and delivered.

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As noted above, beneficial owners of a particular series of securities generally will not receive certificates representing their ownership interests in those securities. However, if:

• DTC notifies us that it is unwilling or unable to continue as a depositary for the global security or securities representing such series of securities or if DTC ceases to be a clearing agency registered under the Exchange Act at a time when it is required to be registered and a successor depositary is not appointed within 90 days of the notification to us or of our becoming aware of DTC’s ceasing to be so registered, as the case may be;

• we determine, in our sole discretion, not to have such securities represented by one or more global securities; or

• an Event of Default has occurred and is continuing with respect to such series of securities,

we will prepare and deliver certificates for such securities in exchange for beneficial interests in the global securities. Any beneficial interest in a global security that is exchangeable under the circumstances described in the preceding sentence will be exchangeable for securities in definitive certificated form registered in the names that the depositary directs. It is expected that these directions will be based upon directions received by the depositary from its participants with respect to ownership of beneficial interests in the global securities.

Euroclear and Clearstream

If so provided in the applicable prospectus supplement, you may hold interests in a global security through Clearstream Banking S.A., which we refer to as “Clearstream,” or Euroclear Bank S.A./N.V., as operator of the Euroclear System, which we refer to as “Euroclear,” either directly if you are a participant in Clearstream or Euroclear or indirectly through organizations which are participants in Clearstream or Euroclear. Clearstream and Euroclear will hold interests on behalf of their respective participants through customers’ securities accounts in the names of Clearstream and Euroclear, respectively, on the books of their respective U.S. depositaries, which in turn will hold such interests in customers’ securities accounts in such depositaries’ names on DTC’s books.

Clearstream and Euroclear are securities clearance systems in Europe. Clearstream and Euroclear hold securities for their respective participating organizations and facilitate the clearance and settlement of securities transactions between those participants through electronic book-entry changes in their accounts, thereby eliminating the need for physical movement of certificates.

Payments, deliveries, transfers, exchanges, notices and other matters relating to beneficial interests in global securities owned through Euroclear or Clearstream must comply with the rules and procedures of those systems. Transactions between participants in Euroclear or Clearstream, on one hand, and other participants in DTC, on the other hand, are also subject to DTC’s rules and procedures.

Investors will be able to make and receive through Euroclear and Clearstream payments, deliveries, transfers and other transactions involving any beneficial interests in global securities held through those systems only on days when those systems are open for business. Those systems may not be open for business on days when banks, brokers and other institutions are open for business in the United States.

Cross-market transfers between participants in DTC, on the one hand, and participants in Euroclear or Clearstream, on the other hand, will be effected through DTC in accordance with the DTC’s rules on behalf of Euroclear or Clearstream, as the case may be, by their respective U.S. depositaries; however, such cross-market transactions will require delivery of instructions to Euroclear or Clearstream, as the case may be, by the counterparty in such system in accordance with the rules and procedures and within the established deadlines (European time) of such system. Euroclear or Clearstream, as the case may be, will, if the transaction meets its settlement requirements, deliver instructions to its U.S. depositary to take action to effect final settlement on its behalf by delivering or receiving interests in the global securities through DTC, and making or receiving payment in accordance with normal procedures for same-day fund settlement. Participants in Euroclear or Clearstream may not deliver instructions directly to their respective U.S. depositaries.

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Due to time zone differences, the securities accounts of a participant in Euroclear or Clearstream purchasing an interest in a global security from a direct participant in DTC will be credited, and any such crediting will be reported to the relevant participant in Euroclear or Clearstream, during the securities settlement processing day (which must be a business day for Euroclear or Clearstream) immediately following the settlement date of DTC. Cash received in Euroclear or Clearstream as a result of sales of interests in a global security by or through a participant in Euroclear or Clearstream to a direct participant in DTC will be received with value on the settlement date of DTC but will be available in the relevant Euroclear or Clearstream cash account only as of the business day for Euroclear or Clearstream following DTC’s settlement date.

Other

The information in this section of this prospectus concerning DTC, Clearstream, Euroclear and their respective book-entry systems has been obtained from sources that we believe to be reliable, but we do not take responsibility for this information. This information has been provided solely as a matter of convenience. The rules and procedures of DTC, Clearstream and Euroclear are solely within the control of those organizations and could change at any time. Neither we nor the trustee nor any agent of ours or of the trustee has any control over those entities and none of us takes any responsibility for their activities. You are urged to contact DTC, Clearstream and Euroclear or their respective participants directly to discuss those matters. In addition, although we expect that DTC, Clearstream and Euroclear will perform the foregoing procedures, none of them is under any obligation to perform or continue to perform such procedures and such procedures may be discontinued at any time. Neither we nor any agent of ours will have any responsibility for the performance or nonperformance by DTC, Clearstream and Euroclear or their respective participants of these or any other rules or procedures governing their respective operations.

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SELLING SECURITYHOLDERS

Information about selling securityholders, where applicable, will be set forth in a prospectus supplement, in a post-effective amendment or in filings we make with the SEC under the Exchange Act that are incorporated by reference.

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PLAN OF DISTRIBUTION

We or any of the selling securityholders may sell the offered securities from time to time:

• through underwriters or dealers;

• through agents;

• directly to one or more purchasers; or

• through a combination of any of these methods of sale.

We will identify the specific plan of distribution, including any underwriters, dealers, agents or direct purchasers and their compensation in the applicable prospectus supplement.

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LEGAL MATTERS

Latham & Watkins LLP will pass upon certain legal matters relating to the issuance and sale of the securities offered hereby on behalf of EngageSmart, Inc. Additional legal matters may be passed upon for us, the selling securityholders or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The financial statements of EngageSmart, Inc. and subsidiaries incorporated by reference in this Prospectus, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report. Such financial statements are incorporated by reference in reliance upon the report of such firm, given their authority as experts in accounting and auditing.

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8,000,000 Shares

Common Stock

Prospectus Supplement

Goldman Sachs & Co. LLC

J.P. Morgan

BofA Securities

Citigroup

Deutsche Bank Securities

Raymond James

Truist Securities

William Blair

KeyBanc Capital Markets

Needham & Company

Penserra Securities LLC

Roberts & Ryan

R. Seelaus & Co., LLC

February 28, 2023