Adecco Group AG

Prospectus • Sep 27, 2024

SUPPLEMENT DATED 25 SEPTEMBER 2024 TO THE BASE PROSPECTUS DATED 15 MAY 2024

ADECCO GROUP AG (incorporated with limited liability in Switzerland) ADECCO INTERNATIONAL FINANCIAL SERVICES B.V. (incorporated with limited liability in The Netherlands) ADECCO FINANCIAL SERVICES (NORTH AMERICA), LLC (incorporated under the laws of the State of Delaware in the United States of America)

EUR 3,500,000,000 Euro Medium Term Note Programme unconditionally and irrevocably guaranteed by ADECCO GROUP AG

(incorporated with limited liability in Switzerland)

This Supplement (the Supplement) to the Base Prospectus dated 15 May 2024, which comprises a base prospectus for the purposes of the UK Prospectus Regulation for each of Adecco Group AG (in its capacity as Issuer, Adecco, and in its capacity as guarantor of Notes issued by AIFS and AFS (each as defined below), the Guarantor) (the Adecco Prospectus), Adecco International Financial Services B.V. (AIFS) (the AIFS Prospectus) and Adecco Financial Services (North America), LLC (AFS, and together with Adecco and AIFS, the Issuers, and each an Issuer) (the AFS Prospectus, and together with the Adecco Prospectus and the AIFS Prospectus, the Base Prospectus) constitutes a prospectus supplement for the purposes of Article 23 of the UK Prospectus Regulation in relation to Adecco with respect to the Adecco Prospectus, AIFS with respect to the AIFS Prospectus and AFS with respect to the AFS Prospectus, and is prepared in connection with the EUR 3,500,000,000 Euro Medium Term Note Programme (the Programme) established by the Issuers.

Terms defined in the Base Prospectus have the same meaning when used in this Supplement. When used in this Supplement, UK Prospectus Regulation means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

This Supplement is supplemental to, and should be read in conjunction with, the Base Prospectus.

Each of the Issuers and the Guarantor accepts responsibility for the information contained in this Supplement insofar as such information relates to itself. To the best of the knowledge of each of the Issuers and the Guarantor the information contained in this Supplement, insofar as such information relates to itself, is in accordance with the facts and this Supplement makes no omission likely to affect its import.

Purpose of the Supplement

The purpose of this Supplement is to (a) incorporate by reference the consolidated unaudited interim financial statements of Adecco as at and for the six month period ended 30 June 2024; (b) incorporate by reference the consolidated unaudited results of Adecco as at and for the second quarter ended 30 June 2024; and (c) include a new "Significant or Material Change" statement for Adecco.

Adecco's Interim Financial Statements as at and for the six month period ended 30 June 2024

On 6 August 2024, Adecco published its consolidated unaudited interim financial statements as at and for the six month period ended 30 June 2024 (the Adecco Half-Year Interim Financial Statements) as set out on pages 10 to 33 of the 2024 Half Year Report of Adecco Group, which can be found at https://www.adeccogroup.com/-/media/project/adecco-group/adeccogroup/pdf-files/2024-july/Adecco-Group-Half-Year-Report-2024.pdf.

By virtue of this Supplement, the Adecco Half-Year Interim Financial Statements are incorporated in, and form part of, the Base Prospectus including the information set out at the following pages in particular:

Consolidated balance sheets	Page 10
Consolidated statements of operations	Page 11
Consolidated statements of comprehensive income	Page 12
Consolidated statements of cash flows	Pages 13-14
Consolidated statements of changes in shareholders' equity	Page 15
Notes to consolidated financial statements	Pages 16-33

Adecco's Results as at and for the second quarter ended 30 June 2024

On 6 August 2024, Adecco published its consolidated unaudited results as at and for the second quarter ended 30 June 2024 (the Adecco Q2 2024 Results), which can be found at https://www.adeccogroup.com/- /media/project/adecco-group/adeccogroup/pdf-files/2024-july/Adecco-Group-Q224-Results-Press-Release.pdf.

By virtue of this Supplement, the Adecco Q2 2024 Results are incorporated in, and form part of, the Base Prospectus, save for the paragraph titled "Outlook" on page 6 of the Adecco Q2 2024 Results and page 7 of the Adecco Q2 2024 Results which shall not be incorporated in, or form part of, the Base Prospectus.

If documents which are incorporated by reference themselves incorporate any information or other documents therein, either expressly or implicitly, such information or other documents will not form part of this Supplement for the purposes of the UK Prospectus Regulation except where such information or other documents are specifically incorporated by reference into this Supplement.

Any non-incorporated parts of a document referred to in this Supplement (which, for the avoidance of doubt, means any parts not listed in the cross-reference list above or expressly excluded above) are either deemed not relevant for an investor or are otherwise covered elsewhere in this Supplement.

General Information

As a result of the publication of the Adecco Half-Year Interim Financial Statements and the Adecco Q2 2024 Results, and further to the information contained on page 94 of the Base Prospectus in the section headed "General Information – Significant or Material Change", there has been (i) no significant change in the financial performance or financial position of Adecco or of Adecco Group since 30 June 2024 and (ii) no material adverse change in the prospects of Adecco since 31 December 2023.

To the extent that there is any inconsistency between (a) any statement in this Supplement or any statement incorporated by reference into the Base Prospectus by this Supplement and (b) any other statement in or incorporated by reference in the Base Prospectus, the statements in (a) above will prevail.

Save as disclosed in this Supplement, there has been no other significant new factor, material mistake or material inaccuracy relating to information included in the Base Prospectus which may affect the assessment of any Notes since the publication of the Base Prospectus.