WILLIS TOWERS WATSON PLC

Item 1.01 Entry into a Material Definitive Agreement. On December 22, 2025, Willis North America Inc., a Delaware corporation (the “Issuer”), completed an offering of (i) $700,000,000 aggregate principal amount of the Issuer’s 4.550% Senior Notes due 2031 (the “2031 Notes”) and (ii) $300,000,000 aggregate principal amount of the Issuer’s 5.150% Senior Notes due 2036 (the “2036 Notes” and together with the 2031 Notes, the “Notes”). The Notes are fully and unconditionally guaranteed by Willis Towers Watson Public Limited Company, an Irish public limited company and parent company of the Issuer (without any of its consolidated subsidiaries, the “Parent”), Willis Towers Watson Sub Holdings Unlimited Company, a company organized under the laws of Ireland, and Willis Investment UK Holdings Limited, Trinity Acquisition plc and Willis Group Limited, companies organized under the laws of England and Wales (collectively with the Parent, the “Guarantors”). The Notes were sold in a public offering pursuant to a Registration Statement on Form S-3 (File No. 333-285459), and a related prospectus and prospectus supplement filed with the Securities and Exchange Commission. The Notes were issued pursuant to a base indenture, as amended, supplemented or otherwise modified from time to time, dated as of May 16, 2017, among the Issuer, the Guarantors and Computershare Trust Company, National Association (the “Trustee”), as successor to Wells Fargo Bank, National Association, as trustee, as amended by the ninth supplemental indenture, dated as of December 22, 2025, among the Issuer, the Guarantors and the Trustee. The 2031 Notes will mature on March 15, 2031 and the 2036 Notes will mature on March 15, 2036. Interest accrues on the Notes from December 22, 2025 and will be paid in cash on March 15 and September 15 of each year, commencing on September 15, 2026. The Notes are senior unsubordinated unsecured obligations of the Issuer and rank equally in right of payment with all of the Issuer’s existing and future unsubordinated and unsecured senior debt and with the Issuer’s guarantee of all of the existing and future senior debt of the Parent and the other Guarantors, including the Issuer’s 4.650% Senior Notes due 2027, 4.500% Senior Notes due 2028, 2.950% Senior Notes due 2029, 5.350% Senior Notes due 2033, 5.050% Senior Notes due 2048, 3.875% Senior Notes due 2049 and 5.900% Senior Notes due 2054, Trinity Acquisition plc’s 6.125% Senior Notes due 2043 and any debt under the Parent’s senior revolving credit facility. The Notes will be senior in right of payment to any future subordinated debt of the Issuer and are effectively subordinated to all of the Issuer’s existing and future secured debt to the extent of the value of the assets securing such debt. The net proceeds from this offering, after deducting the underwriting discount and estimated offering expenses, are approximately $990 million. If the previously announced Newfront acquisition closes, we intend to use the net proceeds of the offering, together with other potential funding sources and/or cash on hand, to (i) pay the consideration for the Newfront acquisition and related fees, costs and expenses and (ii) repay $550 million aggregate principal amount of the 4.400% senior notes due 2026 and related accrued interest, which shall result in the repayment in full of the 4.400% senior notes due 2026. If the Newfront acquisition does not close, we intend to use the net proceeds from this offering, together with cash on hand, for the repayment in full of the 4.400% senior notes due 2026 and the redemption of the 2036 Notes pursuant to a special mandatory redemption. Any remaining proceeds from the offering will be used for general corporate purposes. The foregoing description of the Ninth Supplemental Indenture is qualified in its entirety by reference to the Ninth Supplemental Indenture, which has been filed as Exhibit 4.1 hereto and is incorporated herein by reference.

Item 8.01 Other Events. In connection with the offering of the Notes, the Parent is filing as Exhibits 5.1 through 5.3 hereto the opinions of counsel addressing the validity of the Notes and the guarantees and certain related matters. Such exhibits are incorporated by reference into the Registration Statement.