As of 1 January 2026, electronic invoicing via the Peppol network will become mandatory for B2B transactions between Belgian VAT-registered businesses. This transition also raises legal questions. What does Peppol mean for the opposability (= enforceability) of your invoice terms and conditions?

As of 1 January 2026, all invoices between Belgian VAT-liable entities (i.e. B2B invoices) must be issued and sent electronically in a way that allows automatic and electronic processing. This is confirmed by the Royal Decree (RD) of 14 July 2025, which also sets out the technical requirements. Peppol BIS will be the standard format.

From 1 January 2026, e-invoicing will be mandatory for all Belgian VAT-registered businesses in a B2B context. This marks a fundamental change in the way companies create, send and receive invoices. But what does this measure mean exactly?