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Peppol mandate Belgium, what changed on 1 January 2026

SealDoc Team · · 4 min read

On 1 January 2026, Belgium switched on its mandatory B2B e-invoicing regime. From that date forward every Belgian VAT-registered business has to send and receive invoices in a structured electronic format over the Peppol network. PDFs by email, even pretty ones with embedded XML, no longer count.

The change has been on the calendar since 2023, but the practical impact only really lands when an outgoing invoice gets bounced because the recipient is not registered in the Peppol Directory. That moment is now happening at scale across Belgium, and it is the most common reason businesses are rushing to upgrade their invoicing stack mid-quarter.

What the mandate actually requires

Three things have to be true for an invoice to be compliant under the new regime:

  1. Structured format. The invoice has to follow the Peppol BIS Billing 3.0 specification: UBL XML, with mandatory fields for VAT, line items, and payment terms.
  2. Peppol delivery. The invoice has to travel over the Peppol four-corner network. Sending the same XML by email does not satisfy the mandate.
  3. Both parties registered. Both the issuer and the receiver have to be registered in the Peppol Directory under their VAT number, with at least the invoice document type enabled.

If any one of those conditions fails, the invoice is technically non-compliant, and your buyer’s accounting system will reject it.

The most common failure mode

We see one pattern over and over: the issuer is registered, the format is correct, but the receiver (usually a smaller supplier or a freelancer) has not yet registered with an Access Point. The invoice gets routed into the void and the supplier never sees it.

This is why we built /check/peppol. You paste in a VAT number, we check the Peppol Directory in real time, and you find out within two seconds whether that party is reachable over Peppol and whether the country mandate applies to them. If they are not reachable, you get a clear list of what they need to do to get on the network.

What this means outside Belgium

Belgium is not alone. The mandate calendar across Europe currently looks like this:

  • Belgium, B2B mandatory since 1 January 2026
  • Germany, phased rollout 2025–2028, B2B receive obligation since 1 January 2025
  • France, receive obligation 1 September 2026, send obligation phased into 2027
  • Poland, KSeF mandatory from 2 April 2026
  • Spain, Crea y Crece transition 2025–2027 depending on revenue size
  • Italy, already mandatory since 2019 (FatturaPA, not Peppol-based)
  • Netherlands, government mandates Peppol; B2B is voluntary but de facto becoming standard
  • Czech Republic, proposed mandate, no fixed date yet

If you trade across borders within the EU, this matters: the mandate that applies depends on where your trading partner is established, not where you are. A Dutch supplier invoicing a Belgian buyer in 2026 has to use Peppol, even though the Netherlands itself has not made it mandatory.

The compliance archive problem

There is a quieter problem hiding underneath the format question: archival. A Peppol invoice is UBL XML. UBL XML is fine for machine processing, but most national tax laws require you to retain a human-readable copy for between 7 and 10 years, in a format that is guaranteed to be openable in a quarter-century.

That is exactly what PDF/A-3 was designed for. A PDF/A-3 file is a PDF that is guaranteed to render the same way decades from now, with the original UBL XML embedded as a structured attachment. Open it in a viewer and you see the human invoice. Open it in an accounting system and you can extract the machine data. Both versions are bit-identical to what was sent, both are inside a single tamper-evident container.

This is what SealDoc does on the post-Peppol side. We take the structured invoice, render it into a Factur-X / ZUGFeRD-compliant PDF/A-3, and produce an evidence pack that includes the RFC 3161 timestamp, the UBL XML, and a manifest hash so you can prove later that nothing was altered.

Action items for the next 30 days

  1. Verify that your own VAT number is reachable: paste it into /check/peppol.
  2. Pick five of your top suppliers and run them through the same check. Anyone showing NotReady needs to register with an Access Point this month.
  3. Confirm with your accounting software vendor that they are sending invoices via a Peppol-certified Access Point, not by SMTP relay.
  4. Check that you are archiving a PDF/A-3 copy of every issued invoice, not just the UBL XML. This is the part most pipelines forget.

Belgium’s mandate is the dress rehearsal for what is coming everywhere else in the next 18 months. Getting it right now means you do not have to rebuild the same plumbing four more times.

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