X0609 4 2026-10-15 0001859690 Arqit Quantum Inc. ARQQ 0001863192 Calabria Carlo true 3 ORCHARD PLACE LONDON X0 SW1H 0BF UNITED KINGDOM 1 0 Ordinary Shares 2026-10-16 4 M 0 919 0 A 234147 D Restricted Share Units 2026-10-15 4 A 0 919 0 A Ordinary Shares 919 919 D Restricted Share Units 2026-10-16 4 M 0 919 0 D Ordinary Shares 919 0 D Restricted Stock Units ("RSUs") convert into ARQQ ordinary shares on a one-for-one basis. The RSUs vested within the week of the grant date. Due to the issuer's status as a foreign private issuer pursuant to Rule 3a12-3(b) under the Securities Exchange Act of 1934 (the "Act"), the reporting person's transactions in the issuer's securities are exempt from Sections 16(b) and 16(c) of the Act. Ex.24 - Power of Attorney /s/ Noleen McDonnell, as Attorney-in-Fact 2026-10-20