X0407 4 2023-06-15 0 0001842718 INTEGRAL AD SCIENCE HOLDING CORP. IAS 0001216495 VEP Group, LLC C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001665262 Vista Equity Partners Fund VI, L.P. C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001665190 Vista Equity Partners Fund VI-A, L.P. C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001665225 VEPF VI FAF, L.P. C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001786024 Vista Equity Partners Fund VI GP, L.P. C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001786074 VEPF VI GP. Ltd. C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001689919 VEPF MANAGEMENT, L.P. C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001569532 VISTA EQUITY PARTNERS MANAGEMENT, LLC C/O VISTA EQUITY PARTNERS 4 EMBARCADERO CENTER, 20TH FL. SAN FRANCISCO CA 94111 0 0 1 0 0001216497 SMITH ROBERT F C/O VISTA EQUITY PARTNERS 401 CONGRESS DRIVE, SUITE 3100 AUSTIN TX 78701 0 0 1 0 0 Common Stock, $0.001 par value 2023-06-15 4 S 0 5220000 18.13 D 77660001 I See Footnotes Represents (i) 3,229,655 shares of Common Stock, $0.001 par value ("Common Stock") sold by Vista Equity Partners Fund VI, L.P. ("VEPF VI"), (ii) 1,951,044 shares of Common Stock sold by Vista Equity Partners Fund VI-A, L.P. ("VEPF VI-A") and (iii) 39,301 shares of Common Stock sold by VEPF VI FAF, L.P. ("VEPF FAF," and collectively with VEPF VI and VEPF VI-A, the "Vista Funds"). Consists of (i) 48,048,851 shares of Common Stock held by VEPF VI, (ii) 29,026,459 shares of Common Stock held by VEPF VI-A and (iii) 584,691 shares of Common Stock held by VEPF FAF. Vista Equity Partners Fund VI GP, L.P. ("Fund VI GP") is the sole general partner of each of the Vista Funds. Fund VI GP's sole general partner is VEPF VI GP, Ltd. ("Fund VI UGP"). Robert F. Smith is the sole director and one of 11 members of Fund VI UGP. VEPF Management, L.P. ("Management Company") is the sole management company of each of the Vista Funds. The Management Company's sole general partner is VEP Group, LLC ("VEP Group"), and the Management Company's sole limited partner is Vista Equity Partners Management, LLC ("VEPM"). VEP Group is the Senior Managing Member of VEPM. Robert F. Smith is the sole Managing Member of VEP Group. Consequently, Mr. Smith, Fund VI GP, Fund VI UGP, the Management Company, VEPM and VEP Group may be deemed the beneficial owners of the shares held by the Vista Funds. Each of the Vista Funds, Fund VI GP, Fund VI UGP, the Management Company, VEP Group, VEPM and Mr. Smith expressly disclaim beneficial ownership except to the extent of its or his pecuniary interest and the inclusion of the reported securities in this report shall not be deemed an admission by any of the foregoing of beneficial ownership of any or all of the reported securities for purposes of Section 16 or for any other purpose. /s/ Robert F. Smith, Managing Member of the Senior Managing Member of the General Partner of VEP Group, LLC 2023-06-20 /s/ Robert F. Smith, a Director of the General Partner of the General Partner of Vista Equity Partners Fund VI, L.P. 2023-06-20 /s/ Robert F. Smith, a Director of the General Partner of the General Partner of Vista Equity Partners Fund VI-A, L.P. 2023-06-20 /s/ Robert F. Smith, a Director of the General Partner of the General Partner of VEPF VI FAF, L.P. 2023-06-20 /s/ Robert F. Smith, a Director of the General Partner of Vista Equity Partners Fund VI GP, L.P. 2023-06-20 /s/ Robert F. Smith, a Director of VEPF VI GP. Ltd. 2023-06-20 /s/ Robert F. Smith, Managing Member of the General Partner of VEPF Management, L.P. 2023-06-20 /s/ Robert F. Smith, Managing Member of the General Partner of Vista Equity Partners Management, LLC 2023-06-20 /s/ Robert F. Smith 2023-06-20