HM Treasury confirmed to us that while the department is supportive of the strategy, it has not yet signed up to the Matrix system.51 HM Treasury considers that its Permanent Secretary has the right to decide whether to go ahead with joining the cluster’s system or not subject to further information on benefits and service level, which the department now expects to receive from Matrix in the summer of 2026.52 In subsequent correspondence, the Cabinet Office told us that its own move to shared services will be delayed until December 2026. This delay will affect the HM Treasury Accounting Officer’s final decision on whether to onboard, which will also be delayed to December 2026 assuming there are no further delays.53 These actions, by two major Government departments, send a very poor reputational signal to the rest of the project. 48 Qq 26, Q32, Q50; C&AG’s report, paras 1.5, 2.6 49 Q 44; C&AG’s Report, para 14, Figure 5 50 C&AG’s Report, para 2.8 51 Q 45 52 Q 47 53 Letter from the Cabinet Office to PAC dated 3 June 2026, p.5 15