SCHEDULE 13D/A 0001213900-21-049117 0001883221 XXXXXXXX LIVE 2 Ordinary Shares, par value $0.0025 per share 09/30/2024 false 0001859690 G0567U127 Arqit Quantum Inc.

1st Floor 3 Orchard Place London X0 SW1H OBF

Dennis Smith 41 7979 46387 The Evolution Technology Fund II SCSP Bld F.W. Raiffeisen 15 Luxembourg N4 2411 0001883221 N The Evolution Technology Fund II SCSP b WC N N4 0 397259 0 397259 397259 N 3.1 OO (1) These shares are held by The Evolution Technology Fund II SCSP (the "Fund"). Evolution Equity Partners II S.a r.l. (the "General Partner") is the general partner of the Fund and may be deemed to have voting, investment and dispositive power with respect to these securities. Share amounts reported in this Amendment (as defined below) have been adjusted to reflect the impact of the Reverse Share Split (as defined below). (2) Based on 12,746,713 Ordinary Shares of the Issuer outstanding as of January 27, 2025, as reported in the Issuer's Prospectus Supplement filed with the United States Securities and Exchange Commission (the "Commission") on January 29, 2025 (the "Prospectus"). 0001964876 N Evolution Equity Partners II SARL b AF N N4 0 397259 0 397259 397259 N 3.1 OO (1) These shares are held by the Fund. The General Partner is the general partner of the Fund and may be deemed to have voting, investment and dispositive power with respect to these securities. Share amounts reported in this Amendment have been adjusted to reflect the impact of the Reverse Share Split. (2) Based on 12,746,713 Ordinary Shares of the Issuer outstanding as of January 27, 2025, as reported in the Prospectus. Ordinary Shares, par value $0.0025 per share Arqit Quantum Inc. 1st Floor 3 Orchard Place London X0 SW1H OBF Explanatory Note: This Amendment No. 2 (this "Amendment") amends and supplements the Schedule 13D originally filed by the Reporting Persons with the Commission on September 21, 2021 and amended by Amendment No. 1 filed by the Reporting Persons with the Commission on February 13, 2024 (collectively, the "Original Schedule 13D"). Only those items that are hereby reported are amended; all other items reported in the Original Schedule 13D remain unchanged. Information given in response to each item shall be deemed incorporated by reference in all other items, as applicable. Capitalized terms not defined in this Amendment have the meanings ascribed to them in the Original Schedule 13D. Solely on behalf of, and only to the extent that it relates to the Reporting Persons, Item 5 of the Original Schedule 13D is hereby amended as follows: This information reported below is based on 12,746,713 Ordinary Shares of the Issuer outstanding as of January 27, 2025, as reported in the Prospectus. This Amendment is being filed to update the aggregate number of shares and percentage of the Issuer's Ordinary Shares owned by the Reporting Persons due (a) dilution caused by the Issuer's sales of additional shares of its Ordinary Shares from time to time since the date of the filing of the Original Schedule 13D and (b) the Issuer's consolidation of 25 shares into 1 share effective September 25, 2024 (the "Reverse Share Split"). Such transactions resulted in a decrease of over one percent (1%) in the aggregate percentage ownership reported by the Reporting Persons in the Original Schedule 13D. (a) and (b) See Items 7-11 and 13 of the cover pages of this Amendment for each Reporting Person. (c) Except as set forth in this Schedule 13D, none of the Reporting Persons has engaged in any transaction with respect to the Ordinary Shares. (e) The Reporting Persons ceased to be the beneficial owners of more than five percent (5%) of the Issuer's Ordinary Shares on September 30, 2024. The Evolution Technology Fund II SCSP /s/ Dennis Smith 02/10/2025 Evolution Equity Partners II SARL /s/ Dennis Smith 02/10/2025