Belgium's mandate had the gentlest landing of any in Europe — and then, on 1 April 2026, the gloves came off. Here's where things stand.
The recap
The law of 6 February 2024 made structured e-invoicing mandatory for domestic B2B transactions between Belgian-established VAT taxpayers from 1 January 2026. The default rail is Peppol BIS Billing 3.0 (EN 16931, no national CIUS); parties may agree on another EN 16931-compliant format, but every business must remain capable of receiving via Peppol. Notably, Belgium requires no national accreditation — standard OpenPeppol Access Point certification is the only ticket, which keeps the market open and brutally competitive.
What the tolerance period was — and wasn't
From 1 January to 31 March 2026, taxpayers who could demonstrate reasonable, timely compliance efforts were not sanctioned. It was a grace period for good-faith stragglers, not a postponement. Since 1 April 2026, the graduated fines apply: €1,500 for a first offence, €3,000 for a second, €5,000 for each subsequent one — for lacking the technical means to send or receive structured invoices. The quieter, sharper risk: non-compliant invoices can jeopardize the buyer's VAT deduction, which turns compliance into a supplier-relations issue.
Who's out
A December 2025 clarification confirmed that foreign businesses VAT-registered in Belgium but not established there are excluded from the B2B mandate. B2G flows continue through Mercurius as before.
2028 is the real deadline
Belgium plans to add near-real-time e-reporting around 2028 — a 5-corner evolution in which transaction data also flows to the tax administration, replacing the annual client listing. Every Access Point's architecture decision today should be made with that corner in mind.
Practical advice for the long tail
The enterprises complied in January. What remains is hundreds of thousands of SMEs on Odoo, Exact, Yuki, Teamleader and aging Sage installs — clients who will not run integration projects. The winning AP playbook is volume onboarding: low-touch integration patterns, no ERP projects, days per client. That is the gap PeppolBridge's Belgian rule-pack exists to close — and when the 2028 e-reporting layer lands, it ships as configuration, not as another integration round.
Racing the Belgian long tail?
One European connector layer for Belgium today — France and Germany as rule-packs tomorrow.