ADP issues $1B of 5.000% senior notes due 2036

On May 4, 2026, Automatic Data Processing, Inc. (the “Company”) executed an Underwriting Agreement (attached hereto as Exhibit 1.1 and incorporated herein by reference) with BNP Paribas Securities Corp., BofA Securities, Inc. and J.P. Morgan Securities 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 5.000% senior notes due 2036 (the “Notes”).

The Notes were issued on May 7, 2026 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 Fifth Supplemental Indenture by and between the Company and the Trustee (attached hereto as Exhibit 4.1 and incorporated herein by reference).