What is Peppol? A plain-English guide to e-invoicing

Peppol is a shared set of rules, document formats and a network that lets one business's software send structured e-invoices to another's. Each side connects through a Peppol service provider of its choice, and the two providers deliver the invoice between them.

Think of it as two mail carriers handing over a letter. You will hear about Peppol most when a country starts requiring e-invoices between businesses. This guide explains the idea without the jargon: what the network is, how an invoice travels, and what you need to take part.

Peppol in one paragraph

Peppol is not an app or a website you log in to. Its own organization calls it an interoperability framework: agreements, technical specifications and a network that software providers plug into. Once your software is connected through a provider, you can exchange invoices with any other business on the network, whichever provider they use. The name comes from the original European project, Pan-European Public Procurement Online, which began with cross-border public procurement and grew into a general business network.

Who runs it

The network is governed by OpenPeppol, a non-profit international association established under Belgian law. It took over from the original Peppol project when that project finished in 2012. OpenPeppol sets the rules and specifications; it does not send invoices itself. Accredited service providers do that work, and they agree to the same rules so their systems can talk to each other.

Peppol began as a European project, and many of its users are still in Europe, but its own site notes that it is increasingly used around the world.

How an invoice travels: the four-corner model

The heart of Peppol is the four-corner model. Each "corner" is one party in the journey of an invoice:

Corner	Who it is	What it does
1	The supplier	Creates the invoice in its own software
2	The supplier's service provider	Checks the invoice and sends it over the network
3	The buyer's service provider	Receives the invoice and passes it on
4	The buyer	Reads the invoice into its own software

The important part is the middle. The supplier and the buyer do not need the same provider. Older e-invoicing networks often worked like a closed club: both sides had to sign up with the same company. In Peppol, any accredited provider can deliver to any other, much like phone networks connect calls between carriers.

How does corner 2 know where to deliver? Before sending, the supplier's provider looks up the buyer's Peppol ID in the network's address lookup. The answer says which provider receives invoices for that buyer and which document types the buyer can accept. If the buyer is not registered, the invoice cannot be delivered over Peppol, which is why being findable matters as much as being able to send.

What a Peppol ID is

Every business on the network has a Peppol ID: a scheme code that says what kind of number follows, plus the number itself. The number is often something the business already has, such as a company registration or VAT number. Your service provider registers your ID when you join, and your customers' software uses it to find you.

What gets sent: a structured invoice

A Peppol invoice is data, not a picture of a document. The common format for invoices is Peppol BIS Billing, which builds on the European e-invoicing standard EN 16931 and is exchanged as a UBL file. Because every field has a fixed place, the buyer's software can read the supplier, the amounts and the VAT without anyone retyping them. That is also why a PDF sent by email does not count: the guide on why a PDF invoice is not an e-invoice explains the difference, and what EN 16931 requires goes into the fields.

Why it matters now

Governments use structured e-invoicing to speed up payments, cut errors and, in many countries, to collect better VAT data. Rules differ a lot from country to country. In the EU, public bodies have had to accept e-invoices for years, and several countries are now extending requirements to invoices between businesses. Belgium is one example: since 1 January 2026, nearly all invoices between Belgian VAT-registered businesses must be structured e-invoices, in practice sent over Peppol. The post on Belgium's B2B e-invoicing mandate covers the details. If you invoice in other countries, check each country's own rules and timelines.

How to join, in four steps

1. Check whether you need it. Look at the rules in the countries where you invoice, and ask your bigger customers whether they already receive invoices over Peppol.
2. Pick software and a service provider. Many invoicing tools connect to a provider for you; others ask you to bring your own. The guide to choosing a Peppol access point lists what to compare.
3. Register your Peppol ID. This makes you findable, so suppliers can send to you as well.
4. Clean your customer data. Collect each customer's Peppol ID and check names, VAT numbers and addresses, because receiving software checks them.

Costs vary by provider and plan; does e-invoicing cost extra? explains the usual pricing models.

Frequently asked questions

What does Peppol stand for?

Pan-European Public Procurement Online, the name of the European project it grew out of. Today it is used well beyond public procurement, for invoices between ordinary businesses.

Do both businesses need the same Peppol provider?

No. That is the point of the four-corner model. Each side picks its own accredited provider, and the providers deliver to each other.

Is Peppol used outside Europe?

Yes. It started as a European project, and OpenPeppol notes that it is increasingly used around the world. Whether it is required depends on each country's own rules.

What is a Peppol ID made of?

A scheme code, which says what kind of number it is, and the number itself, often a company or VAT number. Your provider registers it for you so others can find you on the network.