Material Agreement Form 8 K

On September 4, 2024, Automatic Data Processing, Inc. (the "Company") executed an Underwriting Agreement (attached hereto as Exhibit 1.1 and incorporated herein by reference) with BofA Securities, Inc., J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC, as representatives of the underwriters listed in Schedule 1 thereto (collectively, the "Underwriters"), pursuant to which the Company agreed to issue and sell to the Underwriters $1,000,000,000 aggregate principal amount of its 4.450% senior notes due 2034 (the "Notes").

The sale of the Notes was registered with the Securities and Exchange Commission on a Registration Statement on Form S-3(File No. 333-281920)(the "Registration Statement"). The Notes were offered pursuant to a prospectus dated September 4, 2024 and a prospectus supplement dated September 4, 2024.

The Notes were issued on September 9, 2024 pursuant to an Indenture (in substantially the form previously filed with the Registration Statement) by and between the Company and U.S. Bank Trust Company, National Association (as successor in interest to U.S. Bank National Association), as trustee (the "Trustee"), as supplemented by a Third Supplemental Indenture by and between the Company and the Trustee (attached hereto as Exhibit 4.1 and incorporated herein by reference).