SAP Secures £275M HMRC Contract for ECC to S/4HANA Migration

SAP won a £275.37 million (around $370 million) contract from the UK tax collection department, His Majesty’s Revenue & Customs (HMRC). SAP will migrate HMRC’s Enterprise Tax Management Platform (ETMP) from the legacy SAP ECC 6.0 system to SAP S/4HANA.

The contract covers the modernization of HMRC’s core tax management platform, which underpins the administration and processing of UK tax revenues. The ETMP currently handles over £800 billion in tax revenue and payments annually.

Migrating to S/4HANA in HMRC’s Digital Core

The ETMP system represents a large‑scale core‑to‑core ERP migration rather than a functional add‑on or peripheral modernization effort.

Under the project, SAP will migrate HMRC’s ETMP system from SAP ECC 6.0 to SAP S/4HANA, replacing the existing ERP foundation with a HANA‑native digital core. Moving from ECC to S/4HANA in a tax authority environment requires careful sequencing of data migration, system testing, and compliance validation. HMRC’s platform supports high transaction volumes, complex statutory logic, and strict audit requirements.

In terms of the architectural implication of the project, an ECC‑to‑S/4HANA migration of this nature typically requires reviewing and adapting existing custom tax and finance logic to operate within S/4HANA’s data model and application architecture.

This could mean reducing custom code, adjusting data structures for HANA, and redesigning integrations to align with S/4HANA’s modular and extensible design principles.

What This Means for SAPinsiders

Large‑scale SAP migrations are infrastructure decisions, not IT upgrades. Deals of this size signal that core ERP transitions can shape an organization’s operating model for a decade or more. Enterprises should evaluate SAP S/4HANA programs with the same rigor applied to long‑lived platforms that underpin finance, compliance, and core operations.

Vendor selection narrows as regulatory and scale constraints increase. Highly regulated or sovereign environments limit technology and delivery options as complexity grows. Organizations planning similar migrations should assess early whether their requirements effectively constrain supplier choice and delivery models.

Contract structure matters as much as technical architecture. Multi‑year ERP migration agreements lock in delivery models, support assumptions, and commercial terms well beyond go‑live. Large organizations should treat contract design as a core program risk, aligning it with long‑term operational, support, and change requirements.