Peppol is a network for exchanging structured business documents. Instead of emailing a PDF, your store hands the invoice to an access point, the network routes it to the buyer’s access point, and it lands in their accounting software. Belgium made Peppol the required channel for all B2B invoices from 1 January 2026, and several other countries use it for public sector invoicing. You do not connect to Peppol directly: you use a provider that is already connected.
The four corner model in plain words
Peppol works like email, but with rules about the format and the address.
- You, the sender, create the invoice.
- Your access point is the provider that puts it on the network.
- The buyer’s access point receives it.
- The buyer gets the invoice in their system.
Because both providers follow the same specification, neither you nor your customer needs a bilateral integration. That is the whole point: one connection, many trading partners.
What an access point does
An access point validates your invoice against the required format, signs and transmits it, confirms delivery, and tells you when something is rejected. You pay them, usually per document or as a subscription. Choosing one is a commercial decision, not a technical one: the network behaves the same way whichever you pick.
Identifiers: how the network finds your customer
Every participant has an identifier registered in a directory, typically based on a company number or VAT number. Before you can send, you need the buyer’s identifier, and to receive, yours must be registered. Most rejected first invoices come down to a wrong or missing identifier, not a broken file.
The format: Peppol BIS 3.0
Peppol invoices use Peppol BIS Billing 3.0, a profile built on the European standard EN 16931 and expressed in UBL XML. In practice this means your invoice data must be complete and typed: dates as dates, tax categories as codes, buyer identifiers as identifiers. Free-text notes are allowed, but they cannot carry information the format expects in a field.
What this means for a WooCommerce store
WooCommerce already holds most of the data. The gaps are usually the same three.
- No VAT number at checkout, or one that nobody validates.
- Tax categories without reasons, especially for exempt and reverse charge sales.
- Address fields used loosely, with the company name typed into the street line.
Fix those and your invoices will validate. Flexible Invoices issues the documents and validates EU VAT numbers in VIES, and the PEPPOL for Flexible Invoices PRO add-on generates them in the Peppol standard as UBL (XML) files you can download from the invoice edit screen. Putting those files on the network is the access point’s part of the job.
The PEPPOL add-on works with Flexible Invoices PRO, which costs EUR 59 a year for one site. If you expect to need more add-ons, the All Plugins Bundle at EUR 99 a year covers all of them on up to 25 sites.
Ready to send your first Peppol invoice? PEPPOL for Flexible Invoices PRO generates UBL files in the Peppol standard straight from the invoice edit screen. Your access point handles the rest.
Is Peppol only for Belgium?
No. Belgium made it mandatory for domestic B2B, but Peppol is also used for public sector invoicing in many European countries, and in Australia, New Zealand, Singapore and Japan. If you sell to public institutions, you may already have been asked for a Peppol address.
FAQ
- Do I need to join Peppol myself? No. You use an access point provider that is already part of the network.
- Is Peppol free? The network is open, but access points charge for their service. Costs are usually small per document.
- Can I send Peppol invoices to a customer who is not on the network? No. Both sides need to be reachable through the network. For customers outside it, you use whatever channel their country requires.
- What is the difference between Peppol and KSeF? Peppol is a decentralised network with many providers. KSeF is a single government platform in Poland. Both carry structured invoices, but the routing model is different.
- Does Peppol replace my invoicing plugin? No. Something still has to create the invoice, number it and keep the record. Peppol only moves it.
- What happens if an invoice is rejected? Your access point reports the error, you correct the data and resend. The invoice is not considered delivered until it is accepted.
