E-Invoicing in Belgium

Belgium is the purest Peppol mandate in the EU — no alternative channels, no national portal fallback for B2B. This simplifies format handling but creates specific integration requirements.

Peppol-only architecture. Every B2B invoice must flow through the Peppol network. Your pipeline needs a Peppol Access Point connection (either direct certification or via a certified provider). There is no government portal for B2B submission — unlike France or Italy, Belgium has no fallback channel. If your Peppol connection is down, you cannot invoice.

Routing via KBO/BCE. Belgian businesses are identified by their KBO/BCE enterprise number, which maps to their Peppol Participant ID. Your system must resolve the recipient's Peppol ID via SMP lookup before sending. If a recipient isn't registered in the Peppol directory, the invoice cannot be delivered — and they're in violation of the mandate.

B2G via Mercurius. The Mercurius platform serves as the government's Peppol Access Point. B2G invoices follow the same Peppol BIS Billing 3.0 format but route through Mercurius. If your pipeline handles both B2B and B2G, the format is identical — only the routing endpoint differs.

Common integration failures. The top rejection cause is missing or incorrect KBO/BCE number in BT-47 (Buyer Legal Registration Identifier). Belgian Peppol validation also enforces strict VAT number format (BE + 10 digits). If you're migrating from PDF/EDI to Peppol, map your customer master data to KBO/BCE numbers before go-live.