Peppol, for someone who has just received an invoice through it

A network first, a format second

Peppol is an exchange network, comparable in principle to email: every participant is reachable at an address, and anyone on the network can deliver a document to them.

It works in four corners. You hand the invoice to your access point; it delivers to the recipient’s access point; the recipient collects it from theirs. You never need to know which provider your customer uses, exactly as you never need to know who hosts their email.

The name comes from Pan-European Public Procurement On-Line: it was built for European public procurement, then spread to the private sector and beyond Europe.

Peppol BIS Billing 3.0 is UBL

This is the part worth remembering. Peppol BIS Billing 3.0 is not another format beside UBL and CII: it is UBL 2.1 with extra rules.

The official vocabulary calls it a CIUS: a restricted usage specification of EN 16931. Plainly: the European standard allows a great many optional fields, and the Peppol profile makes some of them mandatory, starting with the buyer reference.

The practical consequence: a Peppol invoice opens in any UBL reader. The file starts with <Invoice>, like all UBL, and declares its profile in <cbc:CustomizationID>.

Where you will meet it

• Belgium: mandatory for all B2B transactions between taxable persons since 1 January 2026. It is the channel, and there is no other.
• Netherlands, mandatory towards government since 2017, and one of the largest voluntary B2B Peppol volumes in the world.
• European Union. More member states lean on Peppol rather than build a national platform.
• Beyond Europe: Australia, New Zealand, Singapore and Japan have adopted it.

France went another way, with a national directory and accredited platforms. But the French base formats include UBL 2.1, so the files look very much alike: see who must comply.

What Peppol does not do

The network carries the document and checks its shape. It does not check its substance.

An invoice can cross Peppol without incident and remain commercially unusable: an IBAN with a missing digit, a VAT amount that does not match its taxable base, a total that does not add up, a due date before the issue date. Transport guarantees delivery, not correctness.

That is exactly what the BR-xx rules of EN 16931 are for, and what Lekteo checks on every read.

Opening an invoice received over Peppol

Your access point delivers an .xml file. It does not necessarily show it to you in plain language, and nothing obliges your provider to.

Drop it on the home page: the invoice appears laid out, the declared profile is shown at the top, and any departures from the standard are listed underneath with the real figures. No account, and the file never leaves your browser.