X0609 4 2026-10-06 0001859690 Arqit Quantum Inc. ARQQ 0001840684 Ritchie Garth true 3 ORCHARD PLACE LONDON X0 SW1H 0BF UNITED KINGDOM 1 0 Ordinary Shares 2026-10-06 4 S 0 118 24.1915 D 105834 D 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. /s/ Noleen McDonnell, as Attorney-in-Fact 2026-10-08