1. Policy & Timing Overview
Belgium switches on mandatory structured e-Invoicing for domestic B2B on 1 January 2026. Authorities will apply a Q1 2026 grace period for infringements that arise purely from the new duty, provided companies can show they acted in good faith and on time. This is not a general postponement; the obligation itself begins on schedule.
1.1 Rationale for a narrow grace period
A blanket delay would punish early movers and stall the network effects that make e-invoicing valuable. A narrow grace period keeps momentum while protecting businesses that genuinely started on time but hit implementation snags.
Dates you need to know
1 January 2026 — B2B structured e-invoicing becomes mandatory
January–March 2026 — Grace period for good-faith implementation issues tied to the new duty
From April 2026 — Normal sanctioning resumes
2. Grace-Period Coverage
The grace period only applies to breaches specific to the new requirement—not to classic invoicing mistakes.
2.1 Temporary inability to send/receive structured invoices
A company cannot yet send and/or receive a structured e-invoice for all or some flows (for example, self-billing).
2.2 System limitations at the issuer or provider
A company fails to issue a valid structured e-invoice because its own system—or a third-party solution it relies on—is not yet capable for all cases (e.g., contracting-party issuance in self-billing).
2.3 Invoicing must continue
Even in these cases, businesses must still invoice using an alternative format or delivery method while they finish the structured channel.
3. Evidence of Good-Faith Readiness
Authorities will assess situations case by case. Companies should be ready to evidence concrete work that started before go-live, such as signed access-point or ERP contracts, test transmissions, cutover plans, vendor tickets showing backlogs, or written confirmation that a counterparty is not yet ready for structured self-billing.
4. Structured Invoice Requirements
Belgium’s mandate is about structured, system-to-system e-invoices; emailing PDFs does not meet the requirement. Interoperability aligns to EN 16931 semantics with Peppol BIS as the default exchange profile and network.
5. Penalties After Q1 2026
Once the grace period ends, penalties apply for lacking the technical ability to send or receive structured (Peppol BIS) e-invoices—typically €1,500 (first), €3,000 (second), €5,000 (subsequent) per violation, with a short window to rectify between cycles. General invoicing sanctions—for issues like missing particulars or incorrect VAT—remain separate throughout.
6. Supply-Chain Readiness & Reciprocity
E-invoicing relies on reciprocity. The more counterparties are ready, the smoother the cutover. Where readiness is mixed, document interim handling rules, keep a traceable log for any Q1 exceptions, and lock SLAs with providers covering EN 16931/Peppol compliance, monitoring, and rejection handling.
