Exhibit 99.3
Enterprise Bancorp, Inc. parent company of Enterprise Bank ENDORSEMENT LINE SACKPACK MR A SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 C123456789 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext Your vote matters – here’s how to vote! You may vote online or by phone instead of mailing this card. Votes submitted electronically prior to the meeting must be received by 8:00am., (EDT), on April 3, 2025. Online Go to www.envisionreports.com/EBTC or scan the QR code — login details are located in the shaded bar below. Phone Call toll free 1-800-652-VOTE (8683) within the USA, US territories and Canada Using a black ink pen, mark your votes with an X as shown in this example. Please do not write outside the designated areas. Proxy Card for Special Meeting of Shareholders of Enterprise Bancorp, Inc. 1234 5678 9012 345 IF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE. A Proposals — The Board of Directors recommend a vote FOR all Proposals 1 – 3. For Against Abstain 1. To approve the Agreement and Plan of Merger, dated as of December 8, 2024 (the “merger agreement”), by and among Independent Bank Corp. (“Independent”), Rockland Trust Company, Enterprise Bancorp, Inc. (“Enterprise”), and Enterprise Bank and Trust Company, and to approve the transactions contemplated by the merger agreement, including the merger of Enterprise with and into Independent (the “merger,” with such proposal, the “Enterprise merger proposal”). For Against Abstain 2. To approve, on a non-binding, advisory basis, the compensation payable to the named executive officers of Enterprise in connection with the merger (the “Enterprise compensation proposal”). 3. To authorize the Enterprise board of directors to adjourn or postpone the special meeting, if necessary, to permit further solicitation of proxies in favor of the Enterprise merger proposal or to vote on other matters properly before the special meeting (the “Enterprise adjournment proposal”). B Authorized Signatures — This section must be completed for your vote to count. Please date and sign below. Please sign exactly as name(s) appears hereon. Joint owners should each sign. When signing as attorney, executor, administrator, corporate officer, trustee, guardian, or custodian, please give full title. Date (mm/dd/yyyy) — Please print date below. Signature 1 — Please keep signature within the box. Signature 2 — Please keep signature within the box. MR A SAMPLE (THIS AREA IS SET UP TO ACCOMMODATE 140 CHARACTERS) MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND C 1234567890 J N T 639802 1UPX 0437PH
