Discussion Paper on UK B2B e-Invoicing Regime Now Out

This discussion paper explores the practical, technical and policy considerations shaping the UK’s planned national B2B and B2G e-invoicing mandate, currently targeted for April 2029.

Produced by the UKeLab eInvoicing Advocacy Group, a multi-stakeholder industry forum established in 2024, and endorsed by the GENA Uk Chapter, the paper examines the potential structure of the UK’s e-invoicing Roadmap expected alongside the 2026 Budget, and the broader programme architecture likely required to deliver a nationwide interoperable ecosystem.

The paper is particularly timely given:

• HMRC’s commitment to a “co-creation” model with industry
• The government’s confirmation of a decentralised approach
• Growing discussion around interoperability, service provider models and future CTC capabilities
• Increasing alignment with international frameworks such as Peppol and EN16931

The document explores:

• How the UK may define a compliant VAT eInvoice
• Semantic and syntax considerations for the national data standard
• Interoperability and transmission architecture
• Four-corner and potential future five-corner models
• The role of directories, registries and routing frameworks
• Integration of existing EDI and three-corner networks
• Service provider accreditation and capacity-building
• SME onboarding challenges
• Compliance obligations for both taxpayers and providers
• The governance and project management disciplines required between 2026–2029

The paper additionally examines whether the UK should leverage:

• EN16931:2026
• Peppol BIS and PINT methodologies
• Existing MTD infrastructure
• Future-compatible designs capable of supporting DRR or near real-time tax reporting at a later stage

The discussion also highlights the scale of the transformation:

• An estimated 4 billion UK VAT invoices annually
• Approximately 2.7 million VAT-registered businesses
• The operational challenge of onboarding millions of SMEs into structured data exchange environments

For tax, finance, procurement, ERP, shared services and digital trade leaders, the paper provides a detailed view into the strategic, operational and interoperability questions likely to shape the UK’s national e-invoicing architecture over the next several years.

Download the discussion paper: “Considerations for the UK eInvoicing Mandate Roadmap” – UKeLab, March 2026