Twilio (TWLO) 10-Q 9 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2016	Jul. 31, 2016
Entity Registrant Name	TWILIO INC
Entity Central Index Key	1,447,669
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Common Class A
Entity Common Stock, Shares Outstanding		11,677,315
Common Class B
Entity Common Stock, Shares Outstanding		72,892,409

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 261,386	$ 108,835
Accounts receivable, net	22,981	19,094
Prepaid expenses and other current assets	16,799	8,546
Total current assets	301,166	136,475
Restricted cash	8,611	1,170
Property and equipment, net	20,544	14,058
Intangible assets, net	2,604	2,292
Goodwill	3,165	3,165
Other long term assets	461	356
Total assets	336,551	157,516
Current liabilities:
Accounts payable	8,720	2,299
Accrued expenses and other current liabilities	42,140	31,998
Deferred revenue	8,707	6,146
Total current liabilities	59,567	40,443
Other long-term liabilities	9,751	448
Total liabilities	69,318	40,891
Commitments and contingencies (Note 11)
Stockholders' equity:
Convertible preferred stock		239,911
Class A and Class B common stock	85	17
Additional paid in capital	430,016	22,103
Accumulated deficit	(162,868)	(145,406)
Total stockholders' equity	267,233	116,625
Total liabilities and stockholders' equity	$ 336,551	$ 157,516

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Consolidated Statements of Operations
Revenue	$ 64,510	$ 37,954	$ 123,850	$ 71,319
Cost of revenue	28,203	16,827	55,030	32,372
Gross profit	36,307	21,127	68,820	38,947
Operating expenses:
Research and development	17,369	9,388	32,233	17,868
Sales and marketing	18,156	14,164	31,578	24,033
General and administrative	11,635	7,035	22,228	15,300
Total operating expenses	47,160	30,587	86,039	57,201
Loss from operations	(10,853)	(9,460)	(17,219)	(18,254)
Other expenses, net	(28)	(83)	(46)	(30)
Loss before (provision) benefit for income taxes	(10,881)	(9,543)	(17,265)	(18,284)
(Provision) benefit for income taxes	(113)	(33)	(197)	48
Net loss attributable to common stockholders	$ (10,994)	$ (9,576)	$ (17,462)	$ (18,236)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.45)	$ (0.52)	$ (0.84)	$ (1.01)
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted	24,261,903	18,388,844	20,872,550	18,070,932

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (17,462)	$ (18,236)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,285	1,633
Stock based compensation	8,001	3,567
Provision for doubtful accounts	847	368
Tax benefit related to acquisition		(108)
Tax benefit related to stock-based compensation	12
Write-off of internally developed software	146	87
Changes in operating assets and liabilities:
Accounts receivable	(4,733)	(4,969)
Prepaid expenses and other current assets	(10,212)	(1,815)
Other long term assets	(108)	(86)
Accounts payable	4,648	(78)
Accrued expenses and other current liabilities	8,823	6,660
Deferred revenue	2,561	1,040
Other long term liabilities	9,305	(119)
Net cash provided by (used in) operating activities	5,113	(12,056)
CASH FLOWS FROM INVESTING ACTIVITIES:
Increase in restricted cash	(7,439)
Capitalized software development costs	(5,390)	(3,775)
Purchases of property and equipment	(1,945)	(686)
Purchases of intangible assets	(310)	(113)
Acquisition, net of cash acquired		(1,761)
Net cash used in investing activities	(15,084)	(6,335)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from initial public offering, net of underwriting discounts	160,426
Payments of costs related to initial public offering	(2,099)
Net proceeds from issuance of convertible preferred stock		105,869
Proceeds from exercises of stock options	4,276	1,730
Value of equity awards withheld for tax liabilities	(79)
Repurchases of stock	(2)	(14)
Net cash provided by financing activities	162,522	107,585
NET INCREASE IN CASH AND CASH EQUIVALENTS	152,551	89,194
CASH AND CASH EQUIVALENTS--Beginning of period	108,835	32,627
CASH AND CASH EQUIVALENTS--End of period	261,386	121,821
Cash paid for income taxes	96	15
NON CASH INVESTING AND FINANCING ACTIVITIES
Purchases of property, equipment and intangible assets, accrued but not paid	2,049	50
Stock based compensation capitalized in software development costs	688	372
Vesting of early exercised options	177	121
Series E convertible preferred stock issuance costs accrued but not paid		400
Series T convertible preferred stock issued as part of purchase price in the Authy acquisition		$ 3,087
Costs related to the initial public offering, accrued but not paid	$ 1,930

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2016
Organization and Description of Business
Organization and Description of Business	1. Organization and Description of Business Twilio Inc. (the “Company”) was incorporated in the state of Delaware on March 13, 2008. The Company provides a Cloud Communications Platform that enables developers to build, scale and operate communications within software applications through the cloud as a pay-as-you-go service. The Company’s product offerings fit four basic categories: Programmable Voice, Programmable Messaging, Programmable Video and recently introduced Programmable Wireless. The Company also provides use case products, such as a two-factor authentication solution. The Company’s headquarters are located in San Francisco, California and the Company has subsidiaries in the United Kingdom, Estonia, Ireland, Colombia, Germany, Hong Kong, Singapore and Bermuda. Initial Public Offering In June 2016, the Company completed an initial public offering (“IPO”) in which the Company sold 11,500,000 shares of its newly authorized Class A common stock, which included 1,500,000 shares sold pursuant to the exercise by the underwriters of an option to purchase additional shares, at the public offering price of $15.00 per share. The Company received net proceeds of $155.7 million, after deducting underwriting discounts and commissions and offering expenses paid and payable by the Company, from sales of its shares in the IPO. Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock and all shares of convertible preferred stock then outstanding were converted into 54,508,441 shares of common stock on a one-to-one basis, and then reclassified as shares of Class B common stock. See Note 12 for further discussion of Class A and B common stock. As of June 30, 2016, 11,647,711 shares of the Company’s Class A common stock and 72,878,382 shares of the Company’s Class B common stock were outstanding.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2016
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies (a) Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the final prospectus filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended, on June 23, 2016 (the “Prospectus”). The condensed consolidated balance sheet as of December 31, 2015, included herein, was derived from the audited financial statements as of that date, but does not include all disclosures including certain notes required by U.S. GAAP on an annual reporting basis. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year 2016 or any future period. (b) Principles of Consolidation The condensed consolidated financial statements include the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated. (c) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates are used for, but not limited to, revenue allowances and returns; valuation of the Company’s stock and stock-based awards; recoverability of long-lived and intangible assets; capitalization and useful life of the Company’s capitalized internal-use software; fair value of acquired intangible assets and goodwill; accruals and contingencies. Estimates are based on historical experience and on various assumptions that the Company believes are reasonable under current circumstances. However, future events are subject to change and best estimates and judgments may require further adjustments; therefore, actual results could differ materially from those estimates. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation. (d) Concentration of Credit Risk Financial instruments that potentially expose the Company to a concentration of credit risk consist primarily of cash, cash equivalents, restricted cash and accounts receivable. The Company maintains cash, cash equivalents and restricted cash with financial institutions that management believes are financially sound and have minimal credit risk exposure. The Company sells its services to a wide variety of customers. If the financial condition or results of operations of any one of the large customers deteriorate substantially, operating results could be adversely affected. To reduce credit risk, management performs ongoing credit evaluations of the financial condition of significant customers. The Company does not require collateral from its credit customers and maintains reserves for estimated credit losses on customer accounts when considered necessary. Actual credit losses may differ from the Company’s estimates. As of June 30, 2016 there was one customer organization that represented approximately 12% of the Company’s gross accounts receivable. As of December 31, 2015, two customer organizations represented approximately 11% each of the Company’s gross accounts receivable. In the three months ended June 30, 2016 , one customer organization represented 13% of the Company’s total revenue and in the three months ended June 30, 2015 a different customer organization represented 17% of the Company’s total revenue. In the six months ended June 30, 2016, two customer organizations represented 12% each of the Company’s total revenue, and in the six month ended June 30, 2015 one customer organization represented 18% of the Company’s total revenue. (e) Significant Accounting Policies There have been no changes to our significant accounting policies described in the Prospectus. (f) Recently Issued Accounting Guidance, Not Yet Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Updates (“ASU”) No. 2016-13, “Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments” , which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. The Company is evaluating the impact of this guidance on its condensed consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, “ Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting”. This standard is intended to simplify several areas of accounting for share-based compensation arrangements, including the income tax impact, classification on the statement of cash flows and forfeitures. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. The Company is evaluating the impact of this guidance on its condensed consolidated financial statements and related disclosures. In February, 2016 the FASB issued ASU No. 2016-02, “ Leases” . The standard will affect all entities that lease assets and will require lessees to recognize a lease liability and a right-of-use asset for all leases (except for short-term leases that have a duration of less than one year) as of the date on which the lessor makes the underlying asset available to the lessee. For lessors, accounting for leases is substantially the same as in prior periods. For public companies, the new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. For leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, lessees and lessors must apply a modified retrospective transition approach. While the Company expects the adoption of this standard to result in an increase to the reported assets and liabilities, the Company has not yet determined the full impact that the adoption of this standard will have on its condensed consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, “ Revenue from Contracts with Customers ”. This new guidance will replace most existing U.S. GAAP guidance on this topic. The new revenue recognition standard provides a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB issued ASU 2015-14 which deferred, by one year, the effective date for the new revenue reporting standard for entities reporting under U.S. GAAP. In accordance with the deferral, this guidance will be effective for the Company beginning January 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is permitted beginning January 1, 2017. In March 2016, the FASB issued ASU 2016-08, “ Revenue from Contracts with Customers, Principal versus Agent Considerations (Reporting Revenue Gross versus Net)” clarifying the implementation guidance on principal versus agent considerations. Specifically, an entity is required to determine whether the nature of a promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for the good or service to be provided to the customer by the other party (that is, the entity is an agent). The determination influences the timing and amount of revenue recognition. In April 2016, the FASB issued ASU 2016-10, “Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing” , clarifying the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improve the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity’s promise to grant a license provides a customer with either a right to use the entity’s intellectual property (which is satisfied at a point in time) or a right to access the entity’s intellectual property (which is satisfied over time). In May 2016, the FASB issued ASU 2016-12 “Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients” , which amends the guidance on transition, collectability, noncash consideration and the presentation of sales and other similar taxes. ASU 2016-12 clarifies that, for a contract to be considered completed at transition, all (or substantially all) of the revenue must have been recognized under legacy GAAP. In addition, ASU 2016-12 clarifies how an entity should evaluate the collectability threshold and when an entity can recognize nonrefundable consideration received as revenue if an arrangement does not meet the standard’s contract criteria. The effective date and transition requirements for ASU 2016-08, ASU 2016-10 and ASU 2016-12 are the same as the effective date and transition requirements for ASU 2014-09. The Company is evaluating the impact that these ASUs will have on its condensed consolidated financial statements and related disclosures and has not yet selected a transition method.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
Fair Value Measurements
Fair Value Measurements	3. Fair Value Measurements The following tables provide the assets measured at fair value on a recurring basis as of June 30, 2016 and December 31, 2015 (in thousands): Total Carrying As of June 30, 2016 Value Level 1 Level 2 Level 3 Total Financial Assets: Money market funds (included in cash and cash equivalents) $ $ $ — $ — $ Total financial assets $ $ $ — $ — $ Total Carrying As of December 31, 2015 Value Level 1 Level 2 Level 3 Total Financial Assets: Money market funds (included in cash and cash equivalents) $ $ $ — $ — $ Total financial assets $ $ $ — $ — $ The fair value of the Company’s Level 1 financial instruments, approximate their carrying amount due to their short term nature. There were no realized or unrealized losses for the three and six months ended June 30, 2016 and 2015. There were no other-than-temporary impairments for these instruments as of June 30, 2016 and December 31, 2015.

Property and Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 2016
Property and Equipment
Property and Equipment	4. Property and Equipment Property and equipment consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Capitalized software development costs $ $ Office equipment Furniture and fixtures Software Leasehold improvements Total property and equipment Less: accumulated depreciation and amortization ) ) Total property and equipment, net $ $ Depreciation and amortization expense was $1.6 million and $3.0 million for the three and six months ended June 30, 2016, respectively, and $0.8 million and $1.4 million for the three and six months ended June 30, 2015, respectively. The Company capitalized $3.3 million and $6.1 million of software development costs in the three and six months ended June 30, 2016, respectively, of which $0.4 million and $0.7 million, respectively, was stock-based compensation expense. The Company capitalized $2.4 million and $4.1 million of software development costs in the three and six months ended June 30, 2015, respectively, of which $0.2 million and $0.4 million, respectively, was stock-based compensation expense.

Acquisition of Authy, Inc.

Acquisition of Authy, Inc.	6 Months Ended
	Jun. 30, 2016
Acquisition of Authy, Inc.
Acquisition of Authy, Inc.	5. Acquisition of Authy, Inc. On February 23, 2015, the Company completed its acquisition of Authy, Inc. (“Authy”), a Delaware corporation with operations in Bogota, Colombia and San Francisco, California. Authy had developed a two-factor authentication online security solution. The Company’s purchase price of $6.1 million for all of the outstanding shares of capital stock of Authy consisted of $3.0 million in cash and $3.1 million representing the fair value of 389,733 shares of the Company’s Series T convertible preferred stock, of which 180,000 shares are held in escrow. This escrow is effective until the first anniversary of the closing date, and has continued beyond that date as a result of certain circumstances. As of June 30, 2016 the Company has not released any shares out of the escrow. Additionally, the Company issued 507,885 shares of its Series T convertible preferred stock, which converted into shares of Class B common stock immediately prior to the closing or the IPO, to a former shareholder of Authy that have a fair value of $4.0 million and are subject to graded vesting over a period of 3.6 years, as amended. Of the 507,885 shares, 127,054 shares are subject to additional performance conditions and can be relinquished, if the performance conditions are not met. As of June 30, 2016, 70,251 shares have vested. The acquisition has been accounted for as a business combination and, accordingly, the total purchase price is allocated to the identifiable tangible and intangible assets acquired and the liabilities assumed based on their respective fair values on the acquisition date. The cost of shares subject to vesting and performance conditions is accounted for as a post-acquisition compensation expense and recorded as research and development expense on a straight-line basis as the shares vests and conditions are satisfied. Authy’s results of operations have been included in the condensed consolidated financial statements of the Company from the date of acquisition. This transaction is intended to qualify as a tax-free reorganization under Section 368(a) of the IRS Code. The fair value of the Series T convertible preferred stock was determined by the board of directors of the Company with input from a third-party valuation consultant. The following table presents the purchase price allocation recorded in the Company’s condensed consolidated balance sheet on the acquisition date (in thousands): Total Net tangible assets (3) $ Goodwill (1)(3) Intangible assets (2) Total purchase price $ The Company acquired a net deferred tax liability of $0.1 million in this business combination. (1) Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible assets acquired and liabilities assumed. The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology platform, existing customer base and the future development initiatives of the assembled workforce. None of the goodwill is deductible for tax purposes. (2) Identifiable finite-lived intangible assets were comprised of the following: Total Estimated life (in years) Developed technology $ Customer relationships Trade name Total intangible assets acquired $ (3) As part of net tangible assets, the Company acquired $66,000 in accounts receivable subject to dispute resolution with a customer. The matter was resolved later in 2015 and $52,000 was deemed uncollectible immediately prior to the date of acquisition. The Company’s adjustment of its initial purchase price allocation resulted in an increase to goodwill and decrease to net tangible assets of $52,000. After the adjustment, the purchase price allocation related to this acquisition became final. Goodwill balance as of June 30, 2016 was as follows: Total Balance as of December 31, 2014 $ — Goodwill recorded in connection with Authy acquisition Subsequent adjustment to purchase price allocation Balance as of December 31, 2015 Adjustment to goodwill — Balance as of June 30, 2016 $ The estimated fair value of the intangible assets acquired was determined by the Company, and the Company considered or relied in part upon a valuation report of a third-party expert. The Company used an income approach to measure the fair values of the developed technology and trade names based on the relief-from-royalty method. The Company used an income approach to measure the fair value of the customer relationships based on the multi-period excess earnings method, whereby the fair value is estimated based upon the present value of cash flows that the applicable asset is expected to generate. The Company incurred costs related to this acquisition of $1.5 million, of which $0.3 million and $1.2 million were incurred during the years ended December 31, 2014 and 2015, respectively. All acquisition related costs were expensed as incurred and were recorded in general and administrative expenses in the respective periods. Pro forma results of operations for this acquisition have not been presented as the financial impact to the Company’s condensed consolidated financial statements is inconsequential.

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2016
Intangible Assets
Intangible Assets	6. I ntangible Assets Intangible assets consisted of the following (in thousands): As of June 30, 2016 Gross Accumulated Amortization Net Amortizable intangible assets: Developed technology $ $ ) $ Customer relationships ) Trade name ) Patent ) Total amortizable intangible assets ) Non-amortizable intangible assets: Trademark — Total $ ) $ As of December 31, 2015 Gross Accumulated Amortization Net Amortizable intangible assets: Developed technology $ $ ) $ Customer relationships ) Trade name ) Patent ) Total $ $ ) $ Amortization expense was $0.1 million and $0.3 million for the three and six months ended June 30, 2016, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2015, respectively. Total estimated future amortization expense was as follows (in thousands): Total Years ending December 31: 2016 (remaining six months) $ 2017 2018 2019 2020 Thereafter Total $

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	6 Months Ended
	Jun. 30, 2016
Accrued Expenses and Other Liabilities
Accrued Expenses and Other Liabilities	7. Accrued Expenses and Other Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Accrued payroll and related $ $ Accrued bonus and commission Accrued cost of revenue Sales and other taxes payable Accrued other expense Total accrued expenses and other current liabilities $ $ Other long-term liabilities consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Deferred rent $ $ Accrued other expense Total accrued expenses and other current liabilities $ $

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	6 Months Ended
	Jun. 30, 2016
Supplemental Balance Sheet Information
Supplemental Balance Sheet Information	8. Supplemental Balance Sheet Information (a) Allowance for doubtful accounts (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Balance, beginning of period $ $ $ $ Additions Write-offs ) ) ) ) Balance, end of period $ $ $ $ (b) Sales credit reserve (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Balance, beginning of period $ $ $ $ Additions Deductions against reserve ) ) ) ) Balance, end of period $ $ $ $

Revenue by Geographic Area

Revenue by Geographic Area	6 Months Ended
	Jun. 30, 2016
Revenue by Geographic Area
Revenue by Geographic Area	9. Revenue by Geographic Area Revenue by geographic area is based on the IP address at the time of registration. The following table sets forth revenue by geographic area (dollars in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Revenue by geographic area: United States $ $ $ $ International Total $ $ $ $ Percentage of revenue by geographic area: United States % % % % International % % % % Long-lived assets outside the United States were insignificant.

Credit Facility

Credit Facility	6 Months Ended
	Jun. 30, 2016
Credit Facility
Credit Facility	10. Credit Facility Effective January 2015, the Company entered into a $15.0 million revolving credit agreement. Under this agreement, amounts available to be borrowed are based on the Company’s prior month’s monthly recurring revenue. Advances on the line of credit bear interest payable monthly at Wall Street Journal prime rate plus 1%. Borrowings are secured by substantially all of the Company’s assets, with limited exceptions. If there are borrowings under the credit line, there are certain restrictive covenants with which the Company must comply. The credit facility expires in March 2017. As of June 30, 2016 and December 31, 2015, the total amount available to the Company to be borrowed was $15.0 million and the Company had no outstanding balance on this credit facility in either period presented.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies
Commitments and Contingencies	11. Commitments and Contingencies (a) Lease Commitments The Company entered into various non-cancelable operating lease agreements for its facilities over the next five years. Certain operating leases contain provisions under which monthly rent escalates over time. When lease agreements contain escalating rent clauses or free rent periods, the Company recognizes rent expense on a straight-line basis over the term of the lease. The Company’s San Francisco, California facility lease agreement, entered into in January 2016, included a tenant improvement allowance which provided for the landlord to pay for tenant improvements on behalf of the Company for up to $8.3 million. This amount was recorded on the lease inception date into other current assets and current and long-term liabilities in the accompanying condensed consolidated balances sheet. Based on the terms of this landlord incentive and involvement of the Company in the construction process, the leasehold improvements purchased under the landlord incentive were determined to be property of the Company. Rent expense was $2.0 million and $3.0 million, respectively, for the three and six months ended June 30, 2016, and $1.0 million and $1.9 million, respectively, for the three and six months ended June 30, 2015. Additionally, the Company has contractual commitments with its cloud infrastructure provider, network service providers and other vendors that are non-cancellable and expire within one to four years. Future minimum lease payments under non-cancelable operating leases were as follows (in thousands): Year Ending December 31: Total (1) 2016 (remaining six months) $ 2017 2018 2019 2020 Thereafter Total minimum lease payments $ (1) The future minimum lease payments do not reflect the $8.3 million tenant improvement allowance. Future minimum payments under other existing noncancellable purchase obligations were as follows (in thousands). Year Ending December 31: Total 2016 (remaining six months) $ 2017 2018 2019 Total payments $ (b) Legal Matters On April 30, 2015, Telesign Corporation, or Telesign, filed a lawsuit against the Company in the United States District Court, Central District of California (“Telesign I”). Telesign alleges that the Company is infringing three U.S. patents that it holds: U.S. Patent No. 8,462,920, U.S. Patent No. 8,687,038 and U.S. Patent No. 7,945,034. The patent infringement allegations in the lawsuit relate to the Company’s Programmable Authentication products, its two-factor authentication use case and an API tool to find information about a phone number. The Company has petitioned the U.S. Patent and Trademark Office for inter partes review of the patents at issue. On March 9, 2016, the District Court stayed the court case pending the resolution of those proceedings. On June 28, 2016, the Patent and Trademark Office instituted the inter partes review of the '034 patent. Subsequently, on July 8, 2016, the Patent and Trademark Office denied the Company’s petition for inter partes review of the '920 and '038 patents. On July 20, 2016, Telesign applied to the court to lift the stay on Telesign I. The Company has opposed the request. On March 28, 2016, Telesign filed a second lawsuit against the Company in the United States District Court, Central District of California (“Telesign II”), alleging infringement of U.S. Patent No. 9,300,792 held by Telesign. The ‘792 patent is in the same patent family as the ‘920 and ‘038 patents asserted in Telesign I, and the infringement allegations in Telesign II relate to the Company’s Programmable Authentication products and its two-factor authentication use case. On May 23, 2016, the Company moved to dismiss the complaint in Telesign II. On August 3, 2016, the United States District Court, Central District of California, issued an order granting Twilio’s motion to dismiss Telesign’s complaint with leave to amend. Telesign may file an amended complaint by September 2, 2016. With respect to each of the patents asserted in Telesign I and Telesign II, the complaints seek, among other things, to enjoin the Company from allegedly infringing the patents, along with damages for lost profits. On February 18, 2016, a putative class action complaint was filed in the Alameda County Superior Court in California, entitled Angela Flowers v. Twilio Inc. The complaint alleges that the Company’s products permit the interception, recording and disclosure of communications at a customer’s request and in violation of the California Invasion of Privacy Act. The complaint seeks injunctive relief as well as monetary damages. On May 27, 2016, the Company filed a demurrer to the complaint. On August 2, the court issued an order denying the demurrer. Following the denial of the demurrer, the plaintiffs must file an amended complaint by August 18, 2016. Discovery has already begun, and will continue until August 2017, when the plaintiff must file their motion for class certification. The Company intends to vigorously defend these lawsuits and believes it has meritorious defenses to each. It is too early in these matters to reasonably predict the probability of the outcomes or to estimate ranges of possible losses. In addition to the litigations discussed above, from time to time, the Company is a party to legal action and subject to claims that arise in the ordinary course of business. The claims are investigated as they arise and loss estimates are accrued, when probable and reasonably estimable. While it is not feasible to predict or determine the ultimate outcome of these matters, the Company believes that these legal proceedings will not have a material adverse effect on its financial position or results of operations. (c) Indemnification Agreements The Company has signed indemnification agreements with all board members and executive officers. The agreements indemnify the members and officers from claims and expenses on actions brought against the individuals separately or jointly with the Company for Indemnifiable Events. Indemnifiable Events generally mean any event or occurrence related to the fact that the board member or the officer was or is acting in his or her capacity as a board member or an officer for the Company or was or is acting or representing the interests of the Company. In the ordinary course of business, the Company enters into contractual arrangements under which it agrees to provide indemnification of varying scope and terms to business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of the breach of such agreements, intellectual property infringement claims made by third parties and other liabilities relating to or arising from the Company’s various products, or our acts or omissions. In these circumstances, payment may be conditional on the other party making a claim pursuant to the procedures specified in the particular contract. Further, the Company’s obligations under these agreements may be limited in terms of time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments. The terms of such obligations may vary. As of June 30, 2016 and December 31, 2015, no amounts had been accrued. (d) Other taxes The Company conducts operations in many tax jurisdictions throughout the United States. In many of these jurisdictions, non-income-based taxes, such as sales and use and telecommunications taxes are assessed on the Company’s operations. Historically, the Company has not billed or collected these taxes and, in accordance with U.S. GAAP, has recorded a provision for its tax exposure in these jurisdictions when it is both probable that a liability has been incurred and the amount of the exposure can be reasonably estimated. As a result, the Company recorded a liability of $23.3 million and $17.6 million as of June 30, 2016 and December 31, 2015, respectively. These estimates include several key assumptions including, but not limited to, the taxability of the Company’s services, the jurisdictions in which its management believes it has nexus, and the sourcing of revenues to those jurisdictions. In the event these jurisdictions challenge management’s assumptions and analysis, the actual exposure could differ materially from the current estimates.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2016
Stockholders' Equity
Stockholders' Equity	12. Stockholders’ Equity (a) Convertible Preferred Stock Immediately prior to the completion of the IPO, all shares of convertible preferred stock then outstanding were automatically converted into 54,508,441 shares of common stock on a one-to-one basis, and then reclassified as shares of Class B common stock. (b) Preferred Stock As of June 30, 2016, the Company had authorized 100,000,000 shares of preferred stock, par value $0.001, of which no shares were outstanding. (c) Common Stock Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock. Shares offered and sold in the IPO were the newly authorized shares of Class A common stock. As of June 30, 2016 the Company had authorized 1,000,000,000 shares of Class A common stock and 100,000,000 shares of Class B common stock, each par value $0.001 per share, of which 11,647,711 shares and 72,878,382 shares of Class A and Class B common stock, respectively, were issued and outstanding. Holders of Class A and Class B common stock are entitled to one vote per share and ten votes per share, respectively, and the shares of Class A common stock and Class B common stock are identical, except for voting and conversion rights. As of June 30, 2016, the outstanding Class B common stock included 617,634 shares related to the Authy acquisition that were held in escrow. As of December 31, 2015, the Company had 17,324,003 shares of common stock outstanding. As of June 30, 2016, and December 31, 2015, the Company had reserved shares of common stock, on an as-if converted basis, for issuance as follows: As of June 30, 2016 As of December 31, 2015 Conversion of convertible preferred stock outstanding — (1) Stock options issued and outstanding Nonvested restricted stock units issued and outstanding Common stock reserved for Twilio.org Stock-based awards available for grant under 2008 Plan — Stock-based awards available for grant under 2016 Plan — Common stock reserved for issuance under 2016 ESPP plan — Total (1) Includes 687,885 shares of Series T convertible preferred stock related to the Authy acquisition held in escrow as of December 31, 2015. (d) Twilio.org On September 2, 2015, the Company’s board of directors approved the reservation of 888,022 shares of the Company’s common stock, which represented 1% of the Company’s outstanding capital stock on as-converted basis, to fund Twilio.org’s activities. Subsequently, on May 13, 2016, the Company’s board of directors authorized a reduction of 107,625 shares reserved to offset equity grants to Twilio.org employees. As of June 30, 2016, the total remaining shares reserved for Twilio.org was 780,397. Twilio.org is a part of the Company and not a separate legal entity. The objective for Twilio.org is to further the philanthropic goals of the Company. As of June 30, 2016 and December 31, 2015, none of the reserved shares were issued and outstanding.

Stock Based Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2016
Stock Based Compensation
Stock Based Compensation	13. Stock-Based Compensation 2008 Stock Option Plan The Company granted options under its 2008 Stock Option Plan (the “2008 Plan”), as amended and restated, until June 22, 2016, when the plan was terminated in connection with the Company’s IPO. Accordingly, no shares are available for future issuance under this plan. The 2008 Plan continues to govern outstanding equity awards granted thereunder. 2016 Stock Option Plan The Company’s 2016 Equity Incentive Plan (the “2016 Plan”) became effective on June 21, 2016. The 2016 Plan provides for the grant of ISOs, NSOs, restricted stock, RSUs, stock appreciation rights, unrestricted stock awards, performance share awards, dividend equivalent rights and cash-based awards to employees, directors and consultants of the Company. A total of 11,500,000 shares of the Company’s Class A common stock were initially reserved for issuance under the 2016 Plan. These available shares will automatically increase each January 1, beginning on January 1, 2017, by 5% of the number of shares of the Company’s Class A and Class B common stock outstanding on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s Compensation Committee. 2016 Employee Stock Purchase Plan The Company’s Employee Stock Purchase Plan (“2016 ESPP”) became effective on June 21, 2016. A total of 2,400,000 shares of the Company’s Class A common stock were initially reserved for issuance under the 2016 Plan. These available shares will automatically increase each January 1, beginning on January 1, 2017, by the lesser of 1,800,000 shares of the common stock, 1% of the number of shares of the Company’s Class A and Class B common stock outstanding on the immediately preceding December 31 or such lesser number of shares as determined by the Company’s compensation committee. The 2016 ESPP allows eligible employees to purchase shares of the Company’s Class A common stock at a discount of up to 15% through payroll deductions of their eligible compensation, subject to any plan limitations. Except for the initial offering period, the 2016 ESPP provides for separate six-month offering periods beginning each November 16 and May 16 of each fiscal year. On each purchase date, eligible employees will purchase the Company’s stock at a price per share equal to 85% of the lesser of (i) the fair market value of the Company’s common stock on the offering date or (ii) the fair market value of the Company’s common stock on the purchase date. For the three months ended June 30, 2016, no shares of common stock were purchased under the 2016 ESPP and 583,950 shares are expected to be purchased at the end of the initial offering period. The Company selected the Black-Scholes option-pricing model as the method for determining the estimated fair value for the Company’s 2016 ESPP. As of June 30, 2016, total unrecognized compensation cost related to 2016 ESPP was $7.4 million, net of estimated forfeitures, which will be amortized over a weighted-average period of 0.87 years. Stock option activity under the 2008 Plan and the 2016 Plan during the six months ended June 30, 2016 was as follows: Stock Options Number of options outstanding Weighted- average exercise price (per share) Weighted- average remaining contractual term (in years) Aggregate intrinsic value (in thousands) Outstanding options as of December 31, 2015 $ $ Granted Exercised ) Forfeited and cancelled ) Outstanding options as of June 30, 2016 $ $ Options vested and exercisable as of June 30, 2016 $ $ Options vested and expected to vest as of June 30, 2016 $ $ Aggregate intrinsic value represents the difference between the fair value of the Company’s common stock and the exercise price of outstanding “in-the-money” options. Prior to the IPO, the fair value of the Company’s common stock was estimated by the Company’s board of directors. After the IPO, the fair value of the common stock is the Company’s stock price as reported on the New York Stock Exchange. The aggregate intrinsic value of stock options exercised was $8.3 million and $11.3 million for the three and six months ended June 30, 2016, respectively, and $0.9 million and $6.3 million for the three and six months ended June 30, 2015, respectively. The total estimated grant date fair value of options vested was $3.1 million and $6.1 million for the three and six months ended June 30, 2016, respectively, and $1.4 million and $2.7 million for the three and six months ended June 30, 2015, respectively. The weighted-average grant-date fair value of options granted was $5.73 and $5.52 for the three and six months ended June 30, 2016, respectively, and $3.97 and $3.82 for the three and six months ended June 30, 2015, respectively. As of June 30, 2016, total unrecognized compensation cost related to non-vested stock options was $36.2 million, net of estimated forfeitures, which will be amortized over a weighted-average period of 2.70 years. No options were granted to nonemployees in the three and six months ended June 30, 2016, respectively. An immaterial number of options were granted to nonemployees in the three and six months ended June 30, 2015, respectively. Restricted Stock Units Number of awards outstanding Weighted- average grant date fair value (per share) Aggregate intrinsic value (in thousands) Nonvested RSUs as of December 31, 2015 $ $ Granted Vested ) Forfeited and cancelled — — Nonvested RSUs as of June 30, 2016 $ $ Prior to June 22, 2016, the Company granted RSUs (“Pre-IPO RSUs”) under its 2008 Plan to its employees that vested upon the satisfaction of both a service condition and a liquidity condition. The service condition for the majority of these awards will be satisfied over four years. The liquidity condition was satisfied upon occurrence of the Company’s IPO in June 2016. As of March 31, 2016 the Company has deferred recognition of $0.3 million of cumulative share-based compensation expense related to these RSUs for which the service condition was satisfied. This amount was recorded into the quarterly period ended June 30, 2016. RSUs granted on or after the completion of the Company’s IPO (“Post-IPO RSUs”) under the 2016 Plan are not subject to a liquidity condition in order to vest. The compensation expense related to these grants is based on the grant date fair value of the RSUs and is recognized on a ratable basis over the applicable service period, net of estimated forfeitures. The majority of Post-IPO RSUs are earned over a service period of two to four years. As of June 30, 2016, total unrecognized compensation cost related to non-vested RSUs was $7.6 million, net of estimated forfeitures, which will be amortized over a weighted-average period of 3.33 years. Early Exercises of Nonvested Options As of June 30, 2016 and December 31, 2015, the Company recorded a liability of $0.7 million and $0.2 million, respectively, for 130,749 and 52,407 unvested shares, respectively, that were early exercised by employees and were subject to repurchase at the respective period end. These amounts are reflected in current and non-current liabilities on the Company’s consolidated balance sheets. Valuation Assumptions The fair value of employee stock options was estimated on the date of grant using the following assumptions in the Black-Scholes option pricing model: Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Employee Stock Options: Fair value of common stock $10.30-$15.00 $ $10.09-$15.00 $7.07 - 7.78 Expected term (in years) Expected volatility 51.4%-52.2% 52.0% - 53.7% 51.4%-53.0% 52.0% - 54.9% Risk-free interest rate 1.3%-1.4% 1.5% - 1.9% 1.3%-1.5% 1.4% - 1.9% Dividend rate Employee Stock Purchase Plan: Expected term (in years) — — Expected volatility — — Risk-free interest rate — — Dividend rate — — Stock-Based Compensation Expense The Company recorded the total stock-based compensation expense as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Cost of revenue $ $ $ $ Research and development Sales and marketing General and administrative Total $ $ $ $

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	6 Months Ended
	Jun. 30, 2016
Net Loss per Share Attributable to Common Stockholders
Net Loss per Share Attributable to Common Stockholders	14. Net Loss per Share Attributable to Common Stockholders Basic and diluted net loss per common share is presented in conformity with the two-class method required for participating securities. Class A and Class B common stock are the only outstanding equity in the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share. Shares of Class B common stock may be converted into Class A common stock at any time at the option of the stockholder, and are automatically converted into Class A common stock upon sale or transfer, subject to certain limited exceptions. Basic net loss per share attributable to common stockholders is computed using the weighted-average number of common shares outstanding during the period. Diluted net loss per share attributable to common stockholders is computed using the weighted-average number of common shares and, if dilutive, potential common shares outstanding during the period. The dilutive effect of these potential common shares is reflected in diluted earnings per share by application of the treasury stock method. The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Net loss attributable to common stockholders $ ) $ ) $ ) $ ) Weighted-average shares used to compute basic and diluted net loss per share attributable to common stockholders Net loss per share attributable to common stockholders, basic and diluted $ ) $ ) $ ) $ ) The following outstanding shares of common stock equivalents were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive: As of June 30, 2016 2015 Conversion of convertible preferred stock outstanding — (1) Issued and outstanding options Issued and outstanding RSUs — Common stock reserved for Twilio.org — Shares committed under 2016 ESPP — Unvested shares subject to repurchase Total (1) Includes 687,885 shares of Series T convertible preferred stock related to the Authy acquisition held in escrow.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2016
Related Party Transactions
Related Party Transactions	15. Related Party Transactions In 2015, two of the Company’s vendors participated in the Company’s Series E convertible preferred stock financing and owned approximately 2.1% and 1.1%, respectively, of the Company’s outstanding capital stock as of June 30, 2016, and 2.5% and 1.2%, respectively, of the Company’s capital stock, on as-if converted basis, as of December 31, 2015. During the three and six months ended June 30, 2016, the amount of software services the Company purchased from the first vendor was $3.4 million and $6.5 million, respectively. During the three and six months ended June 30, 2015, the amount of software services the Company purchased from the first vendor was $2.7 million and $5.7 million, respectively. The amounts due to this vendor that were accrued as of June 30, 2016 and December 31, 2015 were $2.5 million and $0, respectively. The amount of services the Company purchased from the second vendor was $0.1 million and $0.2 million for the three and six months ended June 30, 2016, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2015, respectively. The amounts due to this vendor that were accrued as of June 30, 2016 and December 31, 2015 were not material.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2016
Summary of Significant Accounting Policies
Basis of Presentation	(a) Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the final prospectus filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended, on June 23, 2016 (the “Prospectus”). The condensed consolidated balance sheet as of December 31, 2015, included herein, was derived from the audited financial statements as of that date, but does not include all disclosures including certain notes required by U.S. GAAP on an annual reporting basis. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year 2016 or any future period.
Principles of Consolidation	(b) Principles of Consolidation The condensed consolidated financial statements include the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated.
Use of Estimates	(c) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates are used for, but not limited to, revenue allowances and returns; valuation of the Company’s stock and stock-based awards; recoverability of long-lived and intangible assets; capitalization and useful life of the Company’s capitalized internal-use software; fair value of acquired intangible assets and goodwill; accruals and contingencies. Estimates are based on historical experience and on various assumptions that the Company believes are reasonable under current circumstances. However, future events are subject to change and best estimates and judgments may require further adjustments; therefore, actual results could differ materially from those estimates. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation.
Concentration of Credit Risk	(d) Concentration of Credit Risk Financial instruments that potentially expose the Company to a concentration of credit risk consist primarily of cash, cash equivalents, restricted cash and accounts receivable. The Company maintains cash, cash equivalents and restricted cash with financial institutions that management believes are financially sound and have minimal credit risk exposure. The Company sells its services to a wide variety of customers. If the financial condition or results of operations of any one of the large customers deteriorate substantially, operating results could be adversely affected. To reduce credit risk, management performs ongoing credit evaluations of the financial condition of significant customers. The Company does not require collateral from its credit customers and maintains reserves for estimated credit losses on customer accounts when considered necessary. Actual credit losses may differ from the Company’s estimates. As of June 30, 2016 there was one customer organization that represented approximately 12% of the Company’s gross accounts receivable. As of December 31, 2015, two customer organizations represented approximately 11% each of the Company’s gross accounts receivable. In the three months ended June 30, 2016 , one customer organization represented 13% of the Company’s total revenue and in the three months ended June 30, 2015 a different customer organization represented 17% of the Company’s total revenue. In the six months ended June 30, 2016, two customer organizations represented 12% each of the Company’s total revenue, and in the six month ended June 30, 2015 one customer organization represented 18% of the Company’s total revenue.
Significant Accounting Policies	(e) Significant Accounting Policies There have been no changes to our significant accounting policies described in the Prospectus.
Recently Issued Accounting Guidance, Not Yet Adopted	(f) Recently Issued Accounting Guidance, Not Yet Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Updates (“ASU”) No. 2016-13, “Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments” , which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. The Company is evaluating the impact of this guidance on its condensed consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, “ Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting”. This standard is intended to simplify several areas of accounting for share-based compensation arrangements, including the income tax impact, classification on the statement of cash flows and forfeitures. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. The Company is evaluating the impact of this guidance on its condensed consolidated financial statements and related disclosures. In February, 2016 the FASB issued ASU No. 2016-02, “ Leases” . The standard will affect all entities that lease assets and will require lessees to recognize a lease liability and a right-of-use asset for all leases (except for short-term leases that have a duration of less than one year) as of the date on which the lessor makes the underlying asset available to the lessee. For lessors, accounting for leases is substantially the same as in prior periods. For public companies, the new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. For leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, lessees and lessors must apply a modified retrospective transition approach. While the Company expects the adoption of this standard to result in an increase to the reported assets and liabilities, the Company has not yet determined the full impact that the adoption of this standard will have on its condensed consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, “ Revenue from Contracts with Customers ”. This new guidance will replace most existing U.S. GAAP guidance on this topic. The new revenue recognition standard provides a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB issued ASU 2015-14 which deferred, by one year, the effective date for the new revenue reporting standard for entities reporting under U.S. GAAP. In accordance with the deferral, this guidance will be effective for the Company beginning January 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is permitted beginning January 1, 2017. In March 2016, the FASB issued ASU 2016-08, “ Revenue from Contracts with Customers, Principal versus Agent Considerations (Reporting Revenue Gross versus Net)” clarifying the implementation guidance on principal versus agent considerations. Specifically, an entity is required to determine whether the nature of a promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for the good or service to be provided to the customer by the other party (that is, the entity is an agent). The determination influences the timing and amount of revenue recognition. In April 2016, the FASB issued ASU 2016-10, “Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing” , clarifying the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improve the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity’s promise to grant a license provides a customer with either a right to use the entity’s intellectual property (which is satisfied at a point in time) or a right to access the entity’s intellectual property (which is satisfied over time). In May 2016, the FASB issued ASU 2016-12 “Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients” , which amends the guidance on transition, collectability, noncash consideration and the presentation of sales and other similar taxes. ASU 2016-12 clarifies that, for a contract to be considered completed at transition, all (or substantially all) of the revenue must have been recognized under legacy GAAP. In addition, ASU 2016-12 clarifies how an entity should evaluate the collectability threshold and when an entity can recognize nonrefundable consideration received as revenue if an arrangement does not meet the standard’s contract criteria. The effective date and transition requirements for ASU 2016-08, ASU 2016-10 and ASU 2016-12 are the same as the effective date and transition requirements for ASU 2014-09. The Company is evaluating the impact that these ASUs will have on its condensed consolidated financial statements and related disclosures and has not yet selected a transition method.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Measurements
Schedule of assets measured at fair value on a recurring basis	The following tables provide the assets measured at fair value on a recurring basis as of June 30, 2016 and December 31, 2015 (in thousands): Total Carrying As of June 30, 2016 Value Level 1 Level 2 Level 3 Total Financial Assets: Money market funds (included in cash and cash equivalents) $ $ $ — $ — $ Total financial assets $ $ $ — $ — $ Total Carrying As of December 31, 2015 Value Level 1 Level 2 Level 3 Total Financial Assets: Money market funds (included in cash and cash equivalents) $ $ $ — $ — $ Total financial assets $ $ $ — $ — $

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2016
Property and Equipment
Schedule of property and equipment	Property and equipment consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Capitalized software development costs $ $ Office equipment Furniture and fixtures Software Leasehold improvements Total property and equipment Less: accumulated depreciation and amortization ) ) Total property and equipment, net $ $

Acquisition of Authy, Inc. (Tab

Acquisition of Authy, Inc. (Tables)	6 Months Ended
	Jun. 30, 2016
Acquisition of Authy, Inc.
Schedule of purchase price allocation	The following table presents the purchase price allocation recorded in the Company’s condensed consolidated balance sheet on the acquisition date (in thousands): Total Net tangible assets (3) $ Goodwill (1)(3) Intangible assets (2) Total purchase price $ The Company acquired a net deferred tax liability of $0.1 million in this business combination. (1) Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible assets acquired and liabilities assumed. The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology platform, existing customer base and the future development initiatives of the assembled workforce. None of the goodwill is deductible for tax purposes. (2) Identifiable finite-lived intangible assets were comprised of the following: Total Estimated life (in years) Developed technology $ Customer relationships Trade name Total intangible assets acquired $ (3) As part of net tangible assets, the Company acquired $66,000 in accounts receivable subject to dispute resolution with a customer. The matter was resolved later in 2015 and $52,000 was deemed uncollectible immediately prior to the date of acquisition. The Company’s adjustment of its initial purchase price allocation resulted in an increase to goodwill and decrease to net tangible assets of $52,000. After the adjustment, the purchase price allocation related to this acquisition became final. Goodwill balance as of June 30, 2016 was as follows: Total Balance as of December 31, 2014 $ — Goodwill recorded in connection with Authy acquisition Subsequent adjustment to purchase price allocation Balance as of December 31, 2015 Adjustment to goodwill — Balance as of June 30, 2016 $
Schedule of identifiable finite lived intangible assets	Total Estimated life (in years) Developed technology $ Customer relationships Trade name Total intangible assets acquired $
Schedule of the goodwill balance	Total Balance as of December 31, 2014 $ — Goodwill recorded in connection with Authy acquisition Subsequent adjustment to purchase price allocation Balance as of December 31, 2015 Adjustment to goodwill — Balance as of June 30, 2016 $

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2016
Intangible Assets
Schedule of intangible assets	Intangible assets consisted of the following (in thousands): As of June 30, 2016 Gross Accumulated Amortization Net Amortizable intangible assets: Developed technology $ $ ) $ Customer relationships ) Trade name ) Patent ) Total amortizable intangible assets ) Non-amortizable intangible assets: Trademark — Total $ ) $ As of December 31, 2015 Gross Accumulated Amortization Net Amortizable intangible assets: Developed technology $ $ ) $ Customer relationships ) Trade name ) Patent ) Total $ $ ) $
Schedule of total estimated future amortization expense	Total estimated future amortization expense was as follows (in thousands): Total Years ending December 31: 2016 (remaining six months) $ 2017 2018 2019 2020 Thereafter Total $

Accrued Expenses and Other Li25

Accrued Expenses and Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2016
Accrued Expenses and Other Liabilities
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Accrued payroll and related $ $ Accrued bonus and commission Accrued cost of revenue Sales and other taxes payable Accrued other expense Total accrued expenses and other current liabilities $ $
Schedule of other long-term liabilities	Other long-term liabilities consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Deferred rent $ $ Accrued other expense Total accrued expenses and other current liabilities $ $

Supplemental Balance Sheet In26

Supplemental Balance Sheet Information (Tables)	6 Months Ended
	Jun. 30, 2016
Supplemental Balance Sheet Information
Schedule of the allowance for doubtful accounts	(a) Allowance for doubtful accounts (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Balance, beginning of period $ $ $ $ Additions Write-offs ) ) ) ) Balance, end of period $ $ $ $
Schedule of the sales credit reserve	(b) Sales credit reserve (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Balance, beginning of period $ $ $ $ Additions Deductions against reserve ) ) ) ) Balance, end of period $ $ $ $

Revenue by Geographic Area (Tab

Revenue by Geographic Area (Tables)	6 Months Ended
	Jun. 30, 2016
Revenue by Geographic Area
Schedule of revenue by geographic area	The following table sets forth revenue by geographic area (dollars in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Revenue by geographic area: United States $ $ $ $ International Total $ $ $ $ Percentage of revenue by geographic area: United States % % % % International % % % %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies
Schedule of future minimum lease payments under noncancelable operating leases	Future minimum lease payments under non-cancelable operating leases were as follows (in thousands): Year Ending December 31: Total (1) 2016 (remaining six months) $ 2017 2018 2019 2020 Thereafter Total minimum lease payments $ (1) The future minimum lease payments do not reflect the $8.3 million tenant improvement allowance.
Schedule of Future minimum payments under other existing noncancellable purchase obligations	Future minimum payments under other existing noncancellable purchase obligations were as follows (in thousands). Year Ending December 31: Total 2016 (remaining six months) $ 2017 2018 2019 Total payments $

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2016
Stockholders' Equity
Schedule of reserved shares of common stock, on an as-if converted basis	As of June 30, 2016 As of December 31, 2015 Conversion of convertible preferred stock outstanding — (1) Stock options issued and outstanding Nonvested restricted stock units issued and outstanding Common stock reserved for Twilio.org Stock-based awards available for grant under 2008 Plan — Stock-based awards available for grant under 2016 Plan — Common stock reserved for issuance under 2016 ESPP plan — Total (1) Includes 687,885 shares of Series T convertible preferred stock related to the Authy acquisition held in escrow as of December 31, 2015.

Stock Based Compensation (Table

Stock Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2016
Stock Based Compensation
Schedule of stock option activity	Number of options outstanding Weighted- average exercise price (per share) Weighted- average remaining contractual term (in years) Aggregate intrinsic value (in thousands) Outstanding options as of December 31, 2015 $ $ Granted Exercised ) Forfeited and cancelled ) Outstanding options as of June 30, 2016 $ $ Options vested and exercisable as of June 30, 2016 $ $ Options vested and expected to vest as of June 30, 2016 $ $
Schedule of restricted stock unit activity	Number of awards outstanding Weighted- average grant date fair value (per share) Aggregate intrinsic value (in thousands) Nonvested RSUs as of December 31, 2015 $ $ Granted Vested ) Forfeited and cancelled — — Nonvested RSUs as of June 30, 2016 $ $
Schedule of valuation assumptions	Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Employee Stock Options: Fair value of common stock $10.30-$15.00 $ $10.09-$15.00 $7.07 - 7.78 Expected term (in years) Expected volatility 51.4%-52.2% 52.0% - 53.7% 51.4%-53.0% 52.0% - 54.9% Risk-free interest rate 1.3%-1.4% 1.5% - 1.9% 1.3%-1.5% 1.4% - 1.9% Dividend rate Employee Stock Purchase Plan: Expected term (in years) — — Expected volatility — — Risk-free interest rate — — Dividend rate — —
Schedule of stock based compensation expense	The Company recorded the total stock-based compensation expense as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Cost of revenue $ $ $ $ Research and development Sales and marketing General and administrative Total $ $ $ $

Net Loss per Share Attributab31

Net Loss per Share Attributable to Common Stockholders (Tables)	6 Months Ended
	Jun. 30, 2016
Net Loss per Share Attributable to Common Stockholders
Schedule of the calculation of basic and diluted net loss per share attributable to common stockholders	The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Net loss attributable to common stockholders $ ) $ ) $ ) $ ) Weighted-average shares used to compute basic and diluted net loss per share attributable to common stockholders Net loss per share attributable to common stockholders, basic and diluted $ ) $ ) $ ) $ )
Schedule of common stock equivalents excluded from the computation of the diluted net loss per share attributable to common stockholders	As of June 30, 2016 2015 Conversion of convertible preferred stock outstanding — (1) Issued and outstanding options Issued and outstanding RSUs — Common stock reserved for Twilio.org — Shares committed under 2016 ESPP — Unvested shares subject to repurchase Total (1) Includes 687,885 shares of Series T convertible preferred stock related to the Authy acquisition held in escrow.

Organization and Description 32

Organization and Description of Business - Organization and Description of Business (Details)	Jun. 30, 2016product
Organization and Description of Business
Number of basic categories of product offerings	4

Organization and Description 33

Organization and Description of Business - Initial Public Offering (Details) $ / shares in Units, $ in Millions	1 Months Ended
	Jun. 30, 2016USD ($)$ / sharesshares
Common Class A
Initial Public Offering
Net proceeds received | $	$ 155.7
Common stock, outstanding (in shares)	11,647,711
Common Class B
Initial Public Offering
Shares upon automatic conversion (in shares)	54,508,441
Conversion ratio	1
Common stock, outstanding (in shares)	72,878,382
IPO | Common Class A
Initial Public Offering
Shares sold (in shares)	11,500,000
Share price (in dollars per share) | $ / shares	$ 15
Over-Allotment Option | Common Class A
Initial Public Offering
Shares sold (in shares)	1,500,000

Summary of Significant Accoun34

Summary of Significant Accounting Policies (Details) - customer	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Accounts Receivable | Credit Concentration Risk
Concentration of Credit Risk
Concentration risk (as a percent)	12.00%				11.00%
Number of customers	1				2
Revenue | Customer Concentration Risk
Concentration of Credit Risk
Concentration risk (as a percent)			12.00%	18.00%
Number of customers			2	1
Revenue | Customer Concentration Risk | Customer One
Concentration of Credit Risk
Concentration risk (as a percent)	13.00%
Revenue | Customer Concentration Risk | Customer Two
Concentration of Credit Risk
Concentration risk (as a percent)		17.00%

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Level 1
Fair Value Measurements
Total financial assets	$ 246,315	$ 80,886
Level 1 | Money Market Funds
Fair Value Measurements
Money market funds (included in cash and cash equivalents)	246,315	80,886
Carrying Value
Fair Value Measurements
Total financial assets	246,315	80,886
Carrying Value | Money Market Funds
Fair Value Measurements
Money market funds (included in cash and cash equivalents)	246,315	80,886
Fair Value
Fair Value Measurements
Total financial assets	246,315	80,886
Fair Value | Money Market Funds
Fair Value Measurements
Money market funds (included in cash and cash equivalents)	$ 246,315	$ 80,886

Fair Value Measurements - Addit

Fair Value Measurements - Additional Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Fair Value Measurements
Realized gains (losses)	$ 0	$ 0	$ 0	$ 0
Unrealized gains (losses)	0	$ 0	0	$ 0
Other-than-temporary impairments	$ 0		$ 0		$ 0

Property and Equipment - Proper

Property and Equipment - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Property and Equipment
Total property and equipment	$ 29,871	$ 20,408
Less: accumulated depreciation and amortization	(9,327)	(6,350)
Total property and equipment, net	20,544	14,058
Capitalized Software Development Costs
Property and Equipment
Total property and equipment	21,997	16,030
Office Equipment
Property and Equipment
Total property and equipment	3,849	2,662
Furniture and Fixtures
Property and Equipment
Total property and equipment	438	393
Software
Property and Equipment
Total property and equipment	865	755
Leasehold Improvements
Property and Equipment
Total property and equipment	$ 2,722	$ 568

Property and Equipment - Deprec

Property and Equipment - Depreciation and Amortization Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Property and Equipment
Depreciation and amortization	$ 1.6	$ 0.8	$ 3	$ 1.4

Property and Equipment - Capita

Property and Equipment - Capitalized Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Property and Equipment
Capitalized software development costs	$ 3,300	$ 2,400	$ 6,100	$ 4,100
Stock based compensation capitalized in software development costs	$ 400	$ 200	$ 688	$ 372

Acquisition of Authy, Inc. - Co

Acquisition of Authy, Inc. - Consideration (Details) - USD ($) $ in Thousands	Feb. 23, 2015	Jun. 30, 2015
Acquisition of Authy, Inc.
Purchase price, fair value of shares of Series T convertible preferred stock		$ 3,087
Authy, Inc.
Acquisition of Authy, Inc.
Purchase price	$ 6,100
Purchase price, cash	3,000
Purchase price, fair value of shares of Series T convertible preferred stock	$ 3,100

Acquisition of Authy, Inc. - 41

Acquisition of Authy, Inc. - Consideration - Shares of Stock (Details) - Authy, Inc. - Preferred Stock - Series T Preferred Stock - USD ($) $ in Millions	Feb. 23, 2015	Jun. 30, 2016	Dec. 31, 2015
Acquisition of Authy, Inc.
Shares issued (in shares)	389,733
Shares held in escrow (in shares)	180,000	617,634	687,885
Shares released from escrow (in shares)		0
Former Shareholder of Acquiree
Acquisition of Authy, Inc.
Fair value	$ 4
Graded vesting period (in years)	3 years 7 months 6 days
Shares issued (in shares)	507,885
Shares subject to additional performance conditions (in shares)	127,054
Shares vested (in shares)		70,251

Acquisition of Authy, Inc. - Pu

Acquisition of Authy, Inc. - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Feb. 23, 2015
Acquisition of Authy, Inc.
Goodwill	$ 3,165	$ 3,165
Authy, Inc.
Acquisition of Authy, Inc.
Intangible assets			$ 1,760
Net deferred tax liability			100
Goodwill deductible for tax purposes			0
Authy, Inc. | Previously Reported
Acquisition of Authy, Inc.
Net tangible assets			1,217
Goodwill			3,113
Intangible assets			1,760
Total purchase price			$ 6,090

Acquisition of Authy, Inc. - Id

Acquisition of Authy, Inc. - Identifiable Finite-lived Intangible Assets (Details) - Authy, Inc. $ in Thousands	Feb. 23, 2015USD ($)
Acquisition of Authy, Inc.
Intangible assets	$ 1,760
Developed Technology
Acquisition of Authy, Inc.
Intangible assets	$ 1,300
Estimated life (in years)	3 years
Customer Relationships
Acquisition of Authy, Inc.
Intangible assets	$ 400
Estimated life (in years)	5 years
Trade Name
Acquisition of Authy, Inc.
Intangible assets	$ 60
Estimated life (in years)	2 years

Acquisition of Authy, Inc. - 44

Acquisition of Authy, Inc. - Purchase Price Allocation Adjustment (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Feb. 23, 2015
Acquisition of Authy, Inc.
Goodwill	$ 3,165	$ 3,165
Authy, Inc.
Acquisition of Authy, Inc.
Accounts receivable subject to dispute			$ 66
Accounts receivable subject to dispute, deemed uncollectable			$ 52
Authy, Inc. | Adjustment
Acquisition of Authy, Inc.
Goodwill		52
Net tangible assets		$ (52)

Acquisition of Authy, Inc. - Go

Acquisition of Authy, Inc. - Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Goodwill
Balance at the beginning of the period	$ 3,165
Goodwill recorded in connection with Authy acquisition		$ 3,113
Subsequent adjustment to purchase price allocation		52
Adjustment to goodwill	0
Balance at the end of the period	$ 3,165	$ 3,165

Acquisition of Authy, Inc. - Ac

Acquisition of Authy, Inc. - Acquisition Costs (Details) - USD ($) $ in Millions	12 Months Ended		24 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
Authy, Inc. | General and Administrative Expense
Acquisition of Authy, Inc.
Acquisition related costs	$ 1.2	$ 0.3	$ 1.5

Intangible Assets - Amortizable

Intangible Assets - Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Intangible Assets
Gross	$ 3,111	$ 2,781
Accumulated Amortization	(770)	(489)
Net	2,341	2,292
Developed Technology
Intangible Assets
Gross	1,300	1,300
Accumulated Amortization	(586)	(370)
Net	714	930
Customer Relationships
Intangible Assets
Gross	400	400
Accumulated Amortization	(108)	(68)
Net	292	332
Trade Name
Intangible Assets
Gross	60	60
Accumulated Amortization	(41)	(26)
Net	19	34
Patent
Intangible Assets
Gross	1,351	1,021
Accumulated Amortization	(35)	(25)
Net	$ 1,316	$ 996

Intangible Assets - Total Intan

Intangible Assets - Total Intangible Assets, Gross (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Intangible Assets
Amortizable intangible assets, gross	$ 3,111	$ 2,781
Trademark	263
Total	$ 3,374	$ 2,781

Intangible Assets - Total Int49

Intangible Assets - Total Intangible Assets, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Intangible Assets
Amortizable intangible assets, net	$ 2,341	$ 2,292
Trademark	263
Total	$ 2,604	$ 2,292

Intangible Assets - Total Int50

Intangible Assets - Total Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Intangible Assets
Gross	$ 3,374	$ 2,781
Accumulated Amortization	(770)	(489)
Net	$ 2,604	$ 2,292

Intangible Assets - Amortizatio

Intangible Assets - Amortization Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Intangible Assets
Amortization expense	$ 0.1	$ 0.1	$ 0.3	$ 0.2

Intangible Assets - Total Estim

Intangible Assets - Total Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Intangible Assets
2016 (remaining six months)	$ 288
2,017	549
2,018	176
2,019	112
2,020	43
Thereafter	1,173
Net	$ 2,341	$ 2,292

Accrued Expenses and Other Li53

Accrued Expenses and Other Liabilities - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accrued Expenses and Other Liabilities
Accrued payroll and related	$ 2,790	$ 972
Accrued bonus and commission	1,284	1,832
Accrued cost of revenue	7,527	6,496
Sales and other taxes payable	23,346	17,634
Accrued other expense	7,193	5,064
Total Accrued expenses and other current liabilities	$ 42,140	$ 31,998

Accrued Expenses and Other Li54

Accrued Expenses and Other Liabilities - Other Long-term Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accrued Expenses and Other Liabilities
Deferred rent	$ 9,515	$ 364
Accrued other expense	236	84
Total other long-term liabilities	$ 9,751	$ 448

Supplemental Balance Sheet In55

Supplemental Balance Sheet Information - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance for doubtful accounts
Balance, beginning of period	$ 651	$ 440	$ 486	$ 210
Additions	544	138	847	368
Write-offs	(400)	(61)	(538)	(61)
Balance, end of period	$ 795	$ 517	$ 795	$ 517

Supplemental Balance Sheet In56

Supplemental Balance Sheet Information - Sales Credit Reserve (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Sales credit reserve
Balance, beginning of period	$ 649	$ 227	$ 714	$ 312
Additions	357	461	843	529
Deductions	(354)	(136)	(905)	(289)
Balance, end of period	$ 652	$ 552	$ 652	$ 552

Revenue by Geographic Area - Re

Revenue by Geographic Area - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue by Geographic Area
Revenue	$ 64,510	$ 37,954	$ 123,850	$ 71,319
United States
Revenue by Geographic Area
Revenue	54,485	32,254	104,993	60,847
International
Revenue by Geographic Area
Revenue	$ 10,025	$ 5,700	$ 18,857	$ 10,472

Revenue by Geographic Area - Pe

Revenue by Geographic Area - Percentage of Revenue by Geographic Area (Details) - Revenue - Geographic Concentration Risk	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
United States
Percentage of revenue by geographic area
Percentage of revenue (as a percent)	84.00%	85.00%	85.00%	85.00%
International
Percentage of revenue by geographic area
Percentage of revenue (as a percent)	16.00%	15.00%	15.00%	15.00%

Credit Facility (Details)

Credit Facility (Details) - Line of Credit - Revolving Credit Facility - Revolving credit agreement - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2015	Jun. 30, 2016	Dec. 31, 2015
Credit Facility
Maximum borrowing capacity	$ 15
Amount available		$ 15	$ 15
Outstanding balance		$ 0	$ 0
Prime Rate
Credit Facility
Basis spread on variable rate (as a percent)	1.00%

Commitments and Contingencies -

Commitments and Contingencies - Leases (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Commitments and Contingencies
Lease agreements term (in years)	5 years
Tenant improvements allowance	$ 8.3

Commitments and Contingencies61

Commitments and Contingencies - Rent Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Commitments and Contingencies
Rent expense	$ 2	$ 1	$ 3	$ 1.9

Commitments and Contingencies62

Commitments and Contingencies - Other Commitments (Details)	6 Months Ended
	Jun. 30, 2016
Minimum
Non-cancellable contractual commitments
Expiration period (in years)	1 year
Maximum
Non-cancellable contractual commitments
Expiration period (in years)	4 years

Commitments and Contingencies63

Commitments and Contingencies - Future Minimum Lease Payments (Details) $ in Thousands	Jun. 30, 2016USD ($)
Future minimum lease payments
2016 (remaining six months)	$ 2,824
2,017	8,596
2,018	6,984
2,019	5,673
2,020	5,408
Thereafter	20,963
Total minimum lease payments	$ 50,448

Commitments and Contingencies64

Commitments and Contingencies - Tenant Improvement Allowance (Details) $ in Millions	Jun. 30, 2016USD ($)
Commitments and Contingencies
Tenant improvements allowance	$ 8.3

Commitments and Contingencies65

Commitments and Contingencies - Future Minimum Payments under Other Existing Noncancellable Purchase Obligations (Details) $ in Thousands	Jun. 30, 2016USD ($)
Future minimum payments under other existing noncancellable purchase obligations
2016 (remaining six months)	$ 3,871
2,017	3,061
2,018	97
2,019	15
Total payments	$ 7,044

Commitments and Contingencies66

Commitments and Contingencies - Indemnification Agreements (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Indemnification Agreement
Indemnification Agreements
Amount accrued	$ 0	$ 0

Commitments and Contingencies67

Commitments and Contingencies - Other Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Commitments and Contingencies
Liability for uncertain tax positions	$ 23.3	$ 17.6

Stockholders' Equity - Converti

Stockholders' Equity - Convertible Preferred Stock (Details)	1 Months Ended
	Jun. 30, 2016$ / sharesshares
Convertible Preferred Stock
Preferred stock, authorized (in shares)	100,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001
Preferred stock, outstanding (in shares)	0
Common Class B
Convertible Preferred Stock
Shares upon automatic conversion (in shares)	54,508,441
Conversion ratio	1

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock (Details)	Jun. 30, 2016Vote$ / sharesshares	Dec. 31, 2015shares	Feb. 23, 2015shares
Common Class A
Stockholders' Equity
Common stock, authorized (in shares)	1,000,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001
Common stock, issued (in shares)	11,647,711
Common stock, outstanding (in shares)	11,647,711
Votes per share | Vote	1
Common Class B
Stockholders' Equity
Common stock, authorized (in shares)	100,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001
Common stock, issued (in shares)	72,878,382
Common stock, outstanding (in shares)	72,878,382
Votes per share | Vote	10
Preferred Stock | Authy, Inc. | Series T Preferred Stock
Stockholders' Equity
Shares held in escrow (in shares)	617,634	687,885	180,000

Stockholders' Equity - Common70

Stockholders' Equity - Common Stock Shares Reserved (Details) - shares	Jun. 30, 2016	Jun. 21, 2016	Dec. 31, 2015	Sep. 02, 2015
Stockholders' Equity
Conversion of convertible preferred stock outstanding (in shares)			54,508,441
Common stock reserved for Twilio.org (in shares)	780,397		888,022	888,022
Reserved shares of common stock (in shares)	32,436,944		72,366,220
2016 Equity Incentive Plan
Stockholders' Equity
Stock based awards available for grant (in shares)	11,446,750
Employee and Nonemployee Stock Options
Stockholders' Equity
Stock options issued and outstanding (in shares)	16,918,789		16,883,837
Employee and Nonemployee Stock Options | 2008 Stock Option Plan
Stockholders' Equity
Stock based awards available for grant (in shares)	0		14,920
Restricted Stock Units (RSUs)
Stockholders' Equity
Nonvested restricted stock units issued and outstanding (in shares)	891,008		71,000
Common Class A | Employee and Nonemployee Stock Options | 2016 Equity Incentive Plan
Stockholders' Equity
Reserved shares of common stock (in shares)		11,500,000
Common Class A | Employee Stock
Stockholders' Equity
Reserved shares of common stock (in shares)	2,400,000	2,400,000

Stockholders' Equity - Shares H

Stockholders' Equity - Shares Held in Escrow (Details) - shares	Jun. 30, 2016	Dec. 31, 2015	Feb. 23, 2015
Series T Preferred Stock | Preferred Stock | Authy, Inc.
Shares held in escrow
Shares held in escrow (in shares)	617,634	687,885	180,000

Stockholders' Equity - Twilio.o

Stockholders' Equity - Twilio.org (Details) - shares	May 13, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 02, 2015
Stockholders' Equity
Common stock reserved for Twilio.org (in shares)		780,397	888,022	888,022
Twilio.org, percentage of outstanding capital stock (as a percent)				1.00%
Twilio.org, authorized reduction in shares reserved (in shares)	107,625
Twilio.org, reserved shares, issued (in shares)		0	0
Twilio.org, reserved shares, outstanding (in shares)		0	0

Stock Based Compensation - 2008

Stock Based Compensation - 2008 Stock Option Plan (Details) - shares	Jun. 30, 2016	Dec. 31, 2015
2008 Stock Option Plan | Employee and Nonemployee Stock Options
Stock Based Compensation
Shares available for future issuance (in shares)	0	14,920

Stock Based Compensation - 2016

Stock Based Compensation - 2016 Stock Option Plan (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 21, 2016	Dec. 31, 2015
Stock Based Compensation
Shares reserved for issuance (in shares)	32,436,944		32,436,944			72,366,220
Stock-based compensation expense	$ 4,976	$ 1,922	$ 8,001	$ 3,567
2016 Equity Incentive Plan | Employee and Nonemployee Stock Options
Stock Based Compensation
Automatic increase percentage (as a percent)					5.00%
2016 Equity Incentive Plan | Employee and Nonemployee Stock Options | Common Class A
Stock Based Compensation
Shares reserved for issuance (in shares)					11,500,000

Stock Based Compensation - 2075

Stock Based Compensation - 2016 Employee Stock Purchase Plan (Details) - USD ($) $ in Millions	Jun. 21, 2016	Jun. 30, 2016	Jun. 30, 2016	May 15, 2017	Dec. 31, 2015
Stock Based Compensation
Shares reserved for issuance (in shares)		32,436,944	32,436,944		72,366,220
Employee Stock
Stock Based Compensation
Automatic increase percentage (as a percent)	1.00%
Unrecognized compensation cost, other than options		$ 7.4	$ 7.4
Weighted-average period (in years)			10 months 13 days
Common Class A | Employee Stock
Stock Based Compensation
Shares reserved for issuance (in shares)	2,400,000	2,400,000	2,400,000
Annual increase amount (in shares)	1,800,000
Purchase price discount (as a percent)	15.00%
Discount from market price, offering date (as a percent)	85.00%
Discount from market price, purchase date (as a percent)	85.00%
Shares purchased (in shares)		0
Common Class A | Employee Stock | Forecast
Stock Based Compensation
Shares purchased (in shares)				583,950

Stock Based Compensation - Stoc

Stock Based Compensation - Stock Option Activity (Details) - Employee and Nonemployee Stock Options $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares
Number of options outstanding
Outstanding options as of the beginning of the period (in shares) | shares	16,883,837
Granted (in shares) | shares	1,894,850
Exercised (in shares) | shares	(1,186,805)
Forfeited and cancelled (in shares) | shares	(673,093)
Outstanding options as of the end of the period (in shares) | shares	16,918,789	16,883,837
Weighted-average exercise price (per share)
Outstanding options as of the beginning of the period (in dollars per share) | $ / shares	$ 5.31
Granted (in dollars per share) | $ / shares	10.73
Exercised (in dollars per share) | $ / shares	3.60
Forfeited and cancelled (in dollars per share) | $ / shares	5.92
Outstanding options as of the end of the period (in dollars per share) | $ / shares	$ 6.01	$ 5.31
Weighted-average remaining contractual term and aggregate intrinsic value
Weighted-average remaining contractual term (in years)	8 years 2 months 27 days	8 years 3 months 18 days
Aggregate intrinsic value | $	$ 515,848	$ 80,758
Options vested and exercisable and options vested and expected to vest
Options vested and exercisable - number of options outstanding (in shares) | shares	5,903,943
Options vested and expected to vest - number of options outstanding (in shares) | shares	15,910,560
Options vested and exercisable - weighted-average exercise price (in dollars per share) | $ / shares	$ 3.53
Options vested and expected to vest - weighted-average exercise price (in dollars per share) | $ / shares	$ 5.89
Options vested and exercisable - weighted-average remaining contractual term (in years)	7 years 2 months 12 days
Options vested and expected to vest - weighted-average remaining contractual term (in years)	8 years 2 months 9 days
Options vested and exercisable - aggregate intrinsic value | $	$ 194,670
Options vested and expected to vest - aggregate intrinsic value | $	$ 487,073

Stock Based Compensation - St77

Stock Based Compensation - Stock Options - Additional Information (Details) - Employee and Nonemployee Stock Options - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Stock Based Compensation
Aggregate intrinsic value of stock options exercised	$ 8.3	$ 0.9	$ 11.3	$ 6.3
Grant date fair value of options vested	$ 3.1	$ 1.4	$ 6.1	$ 2.7
Weighted-average grant date fair value of options granted (in dollars per share)	$ 5.73	$ 3.97	$ 5.52	$ 3.82

Stock Based Compensation - St78

Stock Based Compensation - Stock Options - Unrecognized Compensation Cost (Details) - Employee and Nonemployee Stock Options $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Stock Based Compensation
Unrecognized compensation cost, options	$ 36.2
Weighted-average period (in years)	2 years 8 months 12 days

Stock Based Compensation - Opti

Stock Based Compensation - Options Granted to Nonemployees (Details) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016
Nonemployee Stock Option
Stock Based Compensation
Granted (in shares)	0	0

Stock Based Compensation - Rest

Stock Based Compensation - Restricted Stock Units Activity (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Number of units outstanding
Nonvested RSUs at the beginning of the period (in shares)	71,000
Granted (in shares)	833,762
Vested (in shares)	(13,754)
Nonvested RSUs at the end of the period (in shares)	891,008
Weighted-average grant date fair value (per share)
Nonvested RSUs at the beginning of the period (in dollars per share)	$ 9.39
Granted (in dollars per share)	10.75
Vested (in dollars per share)	10.09
Nonvested RSUs at the end of the period (in dollars per share)	$ 10.65
Aggregate intrinsic value
Aggregate intrinsic value	$ 32,522	$ 716

Stock Based Compensation - Re81

Stock Based Compensation - Restricted Stock Units - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016
Restricted Stock Units (RSUs), Pre-IPO
Stock Based Compensation
Service condition period (in years)		4 years
Share-based compensation expense, service condition satisfied	$ 0.3
Restricted Stock Units (RSUs), Post-IPO | Minimum
Stock Based Compensation
Service condition period (in years)		2 years
Restricted Stock Units (RSUs), Post-IPO | Maximum
Stock Based Compensation
Service condition period (in years)		4 years

Stock Based Compensation - Re82

Stock Based Compensation - Restricted Stock Units - Unrecognized Compensation Cost (Details) - Restricted Stock Units (RSUs) $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Stock Based Compensation
Unrecognized compensation cost, other than options	$ 7.6
Weighted-average period (in years)	3 years 3 months 29 days

Stock Based Compensation - Earl

Stock Based Compensation - Early Exercises of Nonvested Options (Details) - Employee Stock Option - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Stock Based Compensation
Liability for unvested shares	$ 0.7	$ 0.2
Unvested shares that were early exercised (in shares)	130,749	52,407

Stock Based Compensation - Valu

Stock Based Compensation - Valuation Assumptions (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Employee Stock Option
Valuation Assumptions
Fair value of common stock (in dollars per share)		$ 7.74
Expected term (in years)	6 years 29 days	6 years 29 days	6 years 29 days	6 years 29 days
Expected volatility, low end of range (as a percent)	51.40%	52.00%	51.40%	52.00%
Expected volatility, high end of range (as a percent)	52.20%	53.70%	53.00%	54.90%
Risk-free interest rate, low end of range (as a percent)	1.30%	1.50%	1.30%	1.40%
Risk-free interest rate, high end of range (as a percent)	1.40%	1.90%	1.50%	1.90%
Dividend rate (as a percent)	0.00%	0.00%	0.00%	0.00%
Employee Stock
Valuation Assumptions
Expected term (in years)	10 months 24 days		10 months 24 days
Expected volatility (as a percent)	52.00%		52.00%
Risk-free interest rate (as a percent)	0.60%		0.60%
Dividend rate (as a percent)	0.00%		0.00%
Minimum | Employee Stock Option
Valuation Assumptions
Fair value of common stock (in dollars per share)	$ 10.30		$ 10.09	$ 7.07
Maximum | Employee Stock Option
Valuation Assumptions
Fair value of common stock (in dollars per share)	$ 15		$ 15	$ 7.78

Stock Based Compensation - St85

Stock Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Stock-Based Compensation Expense
Stock-based compensation expense	$ 4,976	$ 1,922	$ 8,001	$ 3,567
Cost of Revenue
Stock-Based Compensation Expense
Stock-based compensation expense	28	14	51	28
Research and Development Expense
Stock-Based Compensation Expense
Stock-based compensation expense	2,379	796	3,895	1,459
Selling and Marketing Expense
Stock-Based Compensation Expense
Stock-based compensation expense	1,116	513	1,850	933
General and Administrative Expense
Stock-Based Compensation Expense
Stock-based compensation expense	$ 1,453	$ 599	$ 2,205	$ 1,147

Net Loss per Share Attributab86

Net Loss per Share Attributable to Common Stockholders - General Information (Details)	Jun. 30, 2016Vote
Common Class A
Net Loss Per Share Attributable to Common Stockholders
Votes per share	1
Common Class B
Net Loss Per Share Attributable to Common Stockholders
Votes per share	10

Net Loss per Share Attributab87

Net Loss per Share Attributable to Common Stockholders - Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Loss Per Share Attributable to Common Stockholders
Net loss attributable to common stockholders	$ (10,994)	$ (9,576)	$ (17,462)	$ (18,236)
Weighted average shares used to compute basic and diluted net loss per share attributable to common stockholders	24,261,903	18,388,844	20,872,550	18,070,932
Net loss per share attributable to common stockholders, basic and diluted	$ (0.45)	$ (0.52)	$ (0.84)	$ (1.01)

Net Loss per Share Attributab88

Net Loss per Share Attributable to Common Stockholders - Anti-Dilutive Securities (Details) - shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Anti-dilutive securities
Total	19,304,893	67,560,127
Convertible Preferred Stock
Anti-dilutive securities
Total		53,106,011
Employee and Nonemployee Stock Options
Anti-dilutive securities
Total	16,918,789	14,404,793
Restricted Stock Units (RSUs)
Anti-dilutive securities
Total	891,008
Donor-advised Fund
Anti-dilutive securities
Total	780,397
Employee Stock
Anti-dilutive securities
Total	583,950
Unvested Shares Subject to Repurchase
Anti-dilutive securities
Total	130,749	49,323

Net Loss per Share Attributab89

Net Loss per Share Attributable to Common Stockholders - Shares Held in Escrow (Details) - shares	Jun. 30, 2016	Dec. 31, 2015	Feb. 23, 2015
Authy, Inc. | Preferred Stock | Series T Preferred Stock
Shares held in escrow
Shares held in escrow (in shares)	617,634	687,885	180,000

Related Party Transactions (Det

Related Party Transactions (Details) - Investor $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016USD ($)Counterparty	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)Counterparty	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Related Party Transactions
Vendors, number | Counterparty	2		2
Vendor 1
Related Party Transactions
Ownership percentage (as a percent)	2.10%		2.10%		2.50%
Purchases from vendor	$ 3.4	$ 2.7	$ 6.5	$ 5.7
Due to vendor	$ 2.5		$ 2.5		$ 0
Vendor 2
Related Party Transactions
Ownership percentage (as a percent)	1.10%		1.10%		1.20%
Purchases from vendor	$ 0.1	$ 0.1	$ 0.2	$ 0.2