HM Treasury and the Department for Education are not formally committed to onboarding to their assigned shared services cluster, thereby undermining the strategy. The Cabinet Office has assigned HM Treasury and the Department for Education to the Matrix cluster, with onboarding scheduled for November 2027. The Cabinet Office understands these departments to have unconditionally bought into joining shared services at the outset, and maintains that their participation in shared services is not optional. Both departments have already received funding and invested in modern, cloud-based back-office systems. HM Treasury now claims that it has the right to unilaterally decide whether to proceed with joining its assigned shared services cluster or not, subject to its Accounting Officer’s assessment of further information from the Matrix cluster. Clusters’ delivery has been delayed by the Cabinet Office’s ineffective management of interdependencies with other government digital programmes. According to HM Treasury, delays in Matrix mean the department now expects to receive most of this information in the summer of 2026, before making a decision in December 2026. The Department for Education’s formal commitment is also subject to further information on feasibility and value for money. Accounting Officers report to the Transformation Board on the status of their department’s commitments. For a strategy whose ambition rests on government acting as ‘One Civil Service’, a case-by-case approach sets very a dangerous precedent, rendering the strategy optional and therefore potentially unworkable. 5 recommendation The Cabinet Office should urgently clarify: a. the role of the Transformation Board in securing and maintaining departments’ commitment to shared services; and b. its position on the obligations for departments that currently use modern cloud-based back-office systems to onboard to their assigned shared service cluster; In the Treasury Minute Response, we expect confirma