HM Treasury has yet to confirm whether it will actually use the Workday system it has co-funded since 2021. A formal decision is expected by December 2026, according to a The Register report from 11 June 2026. At stake: the financial viability of a £1.7 billion programme — and a governance precedent with implications far beyond the UK public sector.
Background: The Matrix Cluster Programme
Launched to modernise finance and HR systems across nine UK government departments, the Matrix Cluster programme rests on two key contracts: Workday (SaaS finance and HR, £64 million) and Cognizant as system integrator (£81 million), totalling £144.3 million — significantly below the initial estimate of £215 million.
The scope covers approximately 48,000 users, including staff from the Cabinet Office, the Department for Science, Innovation and Technology (DSIT), the Department for Business and Trade, and several other departments. The original goal is to consolidate 15 instances across nine different legacy applications — a mix of on-premises and cloud systems — into a single SaaS platform.
Workday won the contract over SAP and Oracle. The central irony: HM Treasury, the programme’s primary co-funder at £1.15 billion since 2021, currently runs a heavily customised version of Oracle Fusion and has not yet decided whether to migrate to the new platform.
What This Means for Organisations: The Co-Funder Paradox
This is the governance signal that every CIO or CFO should decode.
A major financial sponsor that refuses — or hesitates — to adopt a solution it mandates for others is not a minor anomaly. It is not merely a reputational issue; it is a fundamental economic miscalculation. The National Audit Office (NAO) has quantified it: without HM Treasury and the Department for Education, the net present value of projected benefits drops from £185 million to £109 million, according to The Register (March 2026). A 41% fall driven entirely by the uncertainty of two participants.
Several operational lessons apply for public-sector organisations and mid-market enterprises evaluating shared ERP programmes:
1. Co-funding is not the same as adoption. Financing a programme and deploying it internally are two distinct decisions, driven by different cost structures, risk appetites, and internal politics. Conflating the two is a classic governance error.
2. Customisation is a structural brake. HM Treasury has specific reasons to hesitate: its Oracle Fusion instance is heavily customised to meet Treasury-specific requirements. Migrating to a standardised SaaS product means accepting reduced functionality, redesigned processes, and a perceived loss of control. That calculation is not irrational — it is simply painful to make in public.
3. Economies of scale collapse without high-volume participants. A shared ERP programme operates like shared infrastructure: marginal cost falls as user count rises. If departments with the largest user bases stay on legacy systems, pooling benefits evaporate — and smaller departments are left bearing disproportionate costs.
4. Workday vs Oracle: the brochure version omits the hard part. For organisations comparing these two platforms, this case makes visible what vendor pitches rarely show. A standardised SaaS ERP is an organisational constraint as much as a technical solution. Departments that have spent years heavily customising Oracle or SAP typically find that migration costs outweigh the projected SaaS benefits — and the NPV analysis backs that view.
What to Watch
Two critical milestones before the end of 2026:
- Late summer 2026: HM Treasury awaits the Matrix programme’s feasibility and cost documents to complete its internal assessment.
- December 2026: target date for a formal decision by the Accounting Officers of HM Treasury and the Department for Education.
If HM Treasury elects to remain on Oracle Fusion, the Matrix programme will need to revise its benefit projections and potentially renegotiate contractual commitments with Workday and Cognizant. If HM Treasury agrees to migrate, integrating a heavily customised Oracle Fusion deployment into a standardised Workday rollout will be a significant competency test for Cognizant — and a market signal for every large-scale ERP transition in Europe.
Either way, the NAO report will serve as required reading for anyone managing a government or shared-services ERP programme.
For further analysis of warning signs in ERP programmes, read our breakdown of the red flags that signal an ERP project in trouble and our guide to ERP post-deployment governance.
