What we know about the UK mandate

The roadmap arrived at the Budget on 28 October 2026, as promised. It settles more than most of the commentary before it expected, and less than anyone building software wanted. The part a developer needs most, the UK data standard, is still a year away.

Every claim in this chapter carries one of three labels:

• Confirmed: an official source says it, in words you could quote.
• Announced: the government has said it will happen, but the detail is not published.
• Speculative: it comes from vendors or advisers, not from HMRC.

The source for everything confirmed or announced is HMRC’s Roadmap for e-invoicing implementation, unless a line says otherwise.

Confirmed

• It starts on 1 April 2029. From that date, VAT-registered persons, public sector bodies included, need to be able to issue and receive VAT invoices as e-invoices. Until the roadmap, the 1 April date only came from vendors.
• It covers invoices between VAT-registered businesses. The requirement applies to taxable transactions between VAT-registered entities where a VAT invoice is required. Sales to consumers are out, invoices from businesses that are not VAT-registered are out, and cross-border transactions are out. Businesses not registered for VAT can use it voluntarily.
• Overseas businesses registered here are in. Non-established taxable persons have the same invoicing requirements as UK businesses.
• There is no phasing by size. The roadmap gives one date and says the requirement should apply broadly to VAT-registered persons. The “large businesses first” schedule you may have read is not in it.
• Peppol is the network. The UK adopts Peppol as its core interoperability framework, and businesses will not need to become Access Points themselves. Chapter 2 covers what that leaves for you to do.
• HMRC is not in the invoice flow. The Peppol Authority will not receive copies of VAT invoices for business transactions. There is no clearance step and no real-time reporting in the 2029 mandate.
• HMRC becomes the UK Peppol Authority, taking the role over from NHS Supply Chain, which holds it today. When the handover happens is not set.
• Access Points must be certified before they can operate on the network.
• EDI and older systems can carry on alongside the new framework, with guidance due in autumn 2027.
• The law goes into Finance Bill 2026, expected to pass in spring 2027.

Announced, without the detail

• The UK data standard. The government will publish a package of core standards, technical specifications, any UK-specific requirements, identifier and validation rules, and guidance. There is a public technical consultation in spring 2027, and the final requirements land between October 2027 and April 2028. The roadmap does not name a format: not Peppol BIS Billing 3.0, not EN 16931, not a “PINT UK”.
• Whether there will be UK-specific rules at all. An annex lists six areas where the UK may need its own requirements, with none decided: business identifiers, security, reporting and transaction information, service levels, local interoperability, and how software providers prove they meet the standards.
• Which business identifiers count. Every user will register an identifier as part of their Peppol participant identity, but the UK has no single identifier that covers every kind of organisation. The decision on which are accepted comes between October 2027 and April 2028. Chapter 3 explains why this matters.
• Certification for Access Points and software providers. Consulted on in spring 2027, with requirements published by spring 2028. The roadmap expects providers to be accredited with the UK Peppol Authority by 1 April 2029.
• An exemption for the digitally excluded, modelled on the one for Making Tax Digital for VAT, with details by April 2028. There may also be narrow technical exemptions where VAT invoicing rules and e-invoicing do not fit together.
• Digital reporting, later, maybe. A consultation on e-invoicing digital reporting launched at the Budget. No decisions have been taken.

The timeline

When	What happens
Spring 2027	Technical consultation on UK standards and Access Point certification. Finance Bill 2026 expected to become law.
By end of 2027	Guidance for specific groups of VAT-registered businesses
October 2027 to April 2028	Final requirements: scope, standards, identifiers, guidance
By April 2028	Exemption details and updated VAT guidance
Spring 2028	Requirements for software providers
Summer 2028	Readiness testing with software providers
Winter 2028	Infrastructure and governance in place
1 April 2029	The mandate applies

Speculative

• That the UK will use Peppol BIS Billing 3.0 as it stands, or a “PINT UK”. Vendors say both. The roadmap says neither. Advisers reading it, such as KPMG, expect international Peppol standards with only limited UK-specific requirements. That is a reasonable reading, and it is still a reading.
• Which identifier wins. A Companies House number, a VAT number, or both. Anyone telling you now is guessing.

What this means if you are building now

The rules the UK will validate against do not exist yet, and will not before late 2027. That changes less than it sounds.

Everything the UK has said points at Peppol, and Peppol already has working rules: EN 16931 and BIS Billing 3.0 are what Belgium has run in production since January 2026. Build against those now, as chapter 5 describes, and treat any UK rules as a layer that arrives on top. A tool claiming “UK compliance” today is claiming something nobody has specified.

Keep identifiers pluggable. A lookup that only knows one UK identifier could be built on the one that does not get picked.

And the spring 2027 consultation is open to anyone. If you are building UK invoicing software, that is the moment to say what would make it easier, before the requirements are final.