<div id="readability-page-1"><div>RNS Number : 2539C Diploma PLC 07 October 2025 10-11 CHARTERHOUSE SQUARE, LONDON EC1M 6EETELEPHONE: +44 (0) 20 7549 57007 October 2025DIRECTOR DECLARATION - EXTERNAL APPOINTMENTDiploma PLC announces that Johnny Thomson, Chief Executive Officer, has been appointed to a non-executive advisory role at TDR Capital LLP (&#34;TDR&#34;) and will join the Strategic Committee of TDR's portfolio company, Applus+.A LawrenceGroup General Counsel &amp; Company Secretary<div><table><tbody><tr><td>For further information please contact:</td><td colspan="2"></td></tr><tr><td></td><td colspan="2"></td></tr><tr><td>Diploma PLC -</td><td colspan="2">+44 (0) 20 7549 5700</td></tr><tr><td colspan="2">Anna Lawrence, Group General Counsel &amp; Company Secretary</td><td></td></tr></tbody></table></div>LEI: 2138008OGI7VYG8FGR19This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact rns@lseg.com or visit www.rns.com.RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our Privacy Policy. END RDNUNVSRVWURRAA</div></div>

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Diploma PLC announces that CEO Johnny Thomson has been appointed to a non-executive advisory role at TDR Capital LLP and will join the Strategic Committee of TDR's portfolio company, Applus+.

REG - Diploma PLC - Director Declaration