What Is E-Invoicing? UK Rules, Peppol and the 2029 Mandate
Key Takeaways
Mandatory e-invoicing starts on 1 April 2029 for B2B and B2G VAT invoices. Confirmed at Budget 2025 after the HMRC and Department for Business and Trade consultation, the mandate shifts the UK from a voluntary regime to a required one for VAT-related transactions between businesses and with the public sector.
A PDF sent by email does not count as an e-invoice. The mandate requires a structured, machine-readable file that passes between buyer and seller software directly, removing the re-typing and transposition errors that come with manual entry.
Peppol is now the confirmed network, not just the likely one. The government confirmed in June 2026 that Peppol will serve as the interoperability framework, using a four-corner model without e-reporting obligations at this stage.
HMRC will not receive invoices in real time in the first phase. Real-time reporting has been deferred until e-invoicing is established, so a future "five-corner" phase is possible but is not part of the current plan.
Budget 2026 is the moment that turns principle into practice. The full implementation roadmap, including technical standards, transitional arrangements and whether the rollout is phased or a single switch-on, is due then — which makes it the point at which practices can start giving clients concrete timelines.
What's actually happening
HMRC and the Department for Business and Trade ran a joint consultation on e-invoicing between February and May 2025, asking businesses of every size (i.e. your clients!) how they'd like electronic invoicing to work. At Budget 2025, the government confirmed the outcome: e-invoicing becomes compulsory for business-to-business and business-to-government VAT invoices from 1 April 2029.
In practice, that means any VAT-registered client invoicing other businesses or the public sector is likely to be in scope. Clients selling to consumers aren't part of the initial rollout, though they may still find larger customers and suppliers asking for structured invoices anyway.
The date itself is settled. What's still being worked out is the detail: whether the switch-on is phased — starting with larger businesses, for example — what the technical standards look like, and how the transition is handled in practice. A full roadmap is due at Budget 2026, following a year of stakeholder workshops running through 2026.
What is e-invoicing, exactly?
An e-invoice is a structured, machine-readable invoice file that one business's software sends directly to another's, where it can be read and processed without anyone re-typing the figures into the accounting system. It carries the same VAT information as a paper invoice, but as data rather than as a document.
So it isn't a PDF attached to an email. A PDF is a picture of an invoice; your software can't act on it without someone reading it and keying it in. With a true e-invoice, buyer and seller software talk to each other directly, cutting out manual entry and the errors that come with it.
Some UK businesses already do this by mutual agreement between trading partners. From 2029, it stops being optional for VAT invoices.
Why Peppol matters
In June 2026, the government confirmed that Peppol will be the network UK e-invoicing runs on. Peppol is an international standard already used across Europe and beyond, built on a "4-corner model" — your software, your access point, your customer's access point, and their software, all exchanging structured data automatically.
For now, the UK's version won't include e-reporting to HMRC alongside the invoice exchange. That could change in a later phase, but it's not part of the current plan.
Your next step
There’s still much still to come with e-invoicing and it lands on top of everything MTD for IT already asks of your practice. Keep an eye on the 2026 budget for relevant updates, and as always, Dext will endeavour to help you keep you ready for whatever comes next.
FAQs
Mandatory e-invoicing applies to B2B and B2G VAT invoices from 1 April 2029. The detailed scope and whether the rollout is phased will be confirmed in the government's Budget 2026 implementation roadmap.
No. A PDF is a digital image of an invoice, not a structured file, so it cannot be read and processed automatically by accounting software. A compliant e-invoice is machine-readable data that moves between the seller's and buyer's systems without anyone re-keying the figures.
Peppol is an international e-invoicing standard already in use across Europe and beyond, and it is the network UK e-invoicing will run on. The four corners are your software, your access point, your customer's access point and their software, exchanging structured invoice data between them rather than routing everything through a central government platform.
VAT-registered businesses issuing VAT invoices to other businesses or to the public sector are expected to be in scope from April 2029. Business-to-consumer transactions are not in the initial scope, though clients outside the mandate may still be asked for structured invoices by larger customers and suppliers.
