What is Peppol? A plain-English guide for UK businesses

Peppol is an international network, plus a shared set of document standards, that lets businesses send e-invoices and other trading documents straight from one company's software to another's. On 23 June 2026 the UK government announced that Peppol "will be the core interoperability network for e-invoicing in the UK", so it will carry most of the invoices covered by the 2029 mandate.

This guide explains what Peppol is, how it works and what is still to be decided for the UK.

Peppol in one paragraph

Think of Peppol as email for invoices, with stricter rules. Each business picks a certified service provider (an Access Point). The provider gives the business a Peppol address, its Peppol ID. To send an invoice, your software hands structured data to your provider. Your provider looks up the buyer's address, checks the invoice against the rules and delivers it to the buyer's provider, which passes it into the buyer's system. Nobody retypes anything, and you do not need a separate link to each customer.

Who runs it?

Peppol is managed by OpenPeppol AISBL, which OpenPeppol describes as "a non-profit international association established under Belgian law". Peppol started in 2008 as a large-scale pilot financed by the European Commission and the project's members. When the project ended in 2012, OpenPeppol took over its services.

OpenPeppol is clear about what Peppol is not: "Peppol is not a portal, or a provider of exchange services." It writes the specifications and the agreements. Certified service providers do the actual sending and receiving.

In each country, a Peppol Authority (usually, but not always, a government body) oversees the service providers in its jurisdiction. Where there is none, OpenPeppol acts as the authority itself. The UK position is explained in Who is the UK Peppol Authority?.

The three building blocks

1. A network (eDelivery). Providers exchange messages over the internet using a common protocol (AS4) and certificates issued under Peppol's own security setup. Before sending, a provider looks up where the buyer can receive. It does this through two registries: the SML and the SMP. See Peppol SMP and SML explained.

2. Standard documents. The invoice itself follows a Peppol Business Interoperability Specification (BIS). For invoices and credit notes this is Peppol BIS Billing 3.0. It is based on the European standard EN 16931 and written in UBL XML. Peppol also has specifications for orders, despatch advice and invoice responses.

3. Agreements. Every certified provider signs a Peppol Service Provider Agreement and passes conformance testing before it can offer Peppol services. That contract framework is what makes it safe to send an invoice to a provider you have never dealt with.

The four-corner model

Peppol uses the four-corner model:

Corner	Who	What they do
C1	Supplier	Creates the invoice in its accounting or ERP software
C2	Supplier's provider	Validates the invoice, looks up the buyer and sends it
C3	Buyer's provider	Receives the invoice and delivers it onward
C4	Buyer	Imports the invoice into its own system

Each side pays only its own provider. The NHS eProcurement Strategy, published by the Department of Health in April 2014, put it this way: "There are no fees payable between access points, with each party paying only their own PEPPOL access point provider."

Why the UK chose it

Peppol is already used in the UK. The 2014 NHS eProcurement Strategy adopted Peppol for purchase orders, despatch advice and invoices across the NHS and its suppliers. NHS Supply Chain now requires its suppliers to issue e-invoices through the Peppol network, as the government noted in its November 2025 consultation response.

Peppol is also used in many EU countries and in places such as Australia, Japan, Singapore and Malaysia. Respondents to the 2025 consultation often named it as their preferred option because of that international reach. For a UK business, it means one connection can, in principle, reach customers at home and abroad.

What is confirmed and what is not

Confirmed (official):

• E-invoicing will be mandatory for B2B and B2G VAT invoices from April 2029.
• Peppol will be the core interoperability network (GOV.UK Tax Update summary, 23 June 2026).
• The model is decentralised, with no central government platform in the invoice flow.
• There will be no real-time reporting to HMRC at launch.

Not yet confirmed:

• Whether the UK will use Peppol BIS Billing 3.0 as it stands or add UK-specific rules (a CIUS).
• Which identifier UK businesses should register under (see Peppol EAS codes for the UK).
• Whether the UK will appoint a national Peppol Authority, and who.
• How service providers will be accredited for the mandate.
• What "core" means for invoices sent outside Peppol. The government has said it will keep engaging on legacy systems that cannot interoperate.

HMRC and the Department for Business and Trade have said they will publish an implementation roadmap at Budget 2026 on 28 October 2026. We expect several of these points to be covered there.

Common misunderstandings

• "Peppol is a file format." It is mainly a network and a rulebook. The format is set by the BIS, usually UBL XML.
• "I have to join Peppol myself." Almost no business connects directly. You connect through your accounting software or a certified provider.
• "A PDF sent over Peppol counts." No. The invoice must be structured data. A PDF can travel as an attachment, but it is not the invoice. See Does a PDF invoice count as an e-invoice?
• "Peppol sends my invoices to HMRC." Not at launch. The UK model has no real-time reporting.

What to do now

1. Ask your accounting or ERP provider whether it can send and receive Peppol BIS Billing 3.0 invoices, and through which certified provider.
2. Check whether your customers are already on Peppol using the Peppol Directory.
3. Find out which Peppol ID you would use. For most VAT-registered UK businesses this is likely to be based on the VAT number. See Peppol participant IDs in the UK.
4. Watch the Budget on 28 October 2026 for the roadmap, and keep an eye on our timeline.