Syensqo SA/NV — Proxy Solicitation & Information Statement 2026

Apr 3, 2026

In order to be admitted to the Ordinary Shareholders' Meeting on Tuesday 5 May 2026, SYENSQO SA must be in possession of this notice of attendance by Wednesday 29 April 2026 at the latest

NOTICE OF ATTENDANCE

I, the undersigned (name, first name and address to be completed)

Owner of the above-mentioned registered shares, advise the said company of my intention to attend the Ordinary Shareholders' Meeting of Syensqo SA that will be held on Tuesday 5 May 2026 at 10:30 am, at SQUARE Brussels, Mont des Arts, 1000 Brussels, with all shares registered under my name at the record date, on Tuesday 21 April 2026 at midnight.

Signed at , on 2026.

Signature(s)

SYENSQO SA must be in possession of this notice of attendance, duly completed and signed, by Wednesday 29 April 2026 at the latest. This document can be sent to Syensqo SA,

• either by post to the following address: Syensqo SA, Shareholders Service, Rue de la Fusée 98, 1130 Brussels,
• or by e-mail to the following address: ag@syensqo.com.