Countries · BE
E-invoicing in Belgium
Belgium became the first EU country to mandate Peppol as the exclusive B2B e-invoicing channel when its mandate went live on January 1, 2026. All domestic B2B transactions between Belgian VAT-registered entities must use Peppol BIS Billing 3.0 in UBL format. B2G e-invoicing has been mandatory via the Mercurius platform since November 2022.
Unlike most EU countries that allow multiple formats, Belgium's mandate requires Peppol BIS Billing 3.0 exclusively for B2B — no CII, no Factur-X, no proprietary formats. Businesses must register in the Peppol network using their KBO/BCE enterprise number as the participant identifier. The Mercurius platform serves as the government's Peppol Access Point for B2G invoices using the same format.
Invoice Navigator validates Belgian e-invoices against both the Belgian CIUS rules and the core EN 16931 standard, with full Peppol BIS Billing 3.0 compliance checking. The validation engine ensures correct KBO/BCE participant lookup and Peppol network routing.
Non-compliance results in invoice rejection via the Peppol network. Non-compliant invoices may not be accepted for VAT deduction. B2G non-compliance results in payment delays and rejection by the Mercurius platform.
TL;DR
| Phase | Status | Scope |
|---|---|---|
| B2G | Live (Nov 2022) | All federal government suppliers |
| B2B | Live (Jan 2026) | All Belgian VAT-registered businesses |
| Code | Rejection | Guide |
|---|---|---|
| BE-01 | Belgian B2B invoices should use Peppol BIS Billing 3.0 | Fix guide |
| BE-02 | Belgian sellers should include enterprise number (KBO/BCE) | Fix guide |
| BR-BE-01 | Enterprise Number Recommended | Fix guide |
| BR-BE-02 | Belgian VAT number recommended | Fix guide |
| BR-BE-10 | Belgian enterprise number format | Fix guide |
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.
Grace period ended March 31, 2026 — penalties active April 1. Belgium's six-month soft-launch grace period closed at the end of Q1 2026. The graduated penalty regime is now in force: €1,500 first offense, €3,000 second, €5,000 third and subsequent offenses per non-compliant invoice. Documented force majeure and technical outages remain valid exceptions. The Hermes platform was decommissioned December 31, 2025 (data archive accessible until March 31, 2026); no government-operated B2B fallback channel remains. See [/blog/belgium-e-invoicing-after-grace-period](/blog/belgium-e-invoicing-after-grace-period) for the post-grace-period playbook.
Belgium B2B mandate confirmed for 2026Major
Belgian government confirms January 1, 2026 start date for structured B2B e-invoicing mandate.
- Is e-invoicing mandatory in Belgium?
- Yes. Belgium's B2B e-invoicing mandate has been live since January 1, 2026, with Peppol BIS Billing 3.0 (UBL) as the exclusive format. B2G e-invoicing has been mandatory via the Mercurius platform since November 2022. The six-month grace period ended March 31, 2026 — graduated penalties (€1,500 / €3,000 / €5,000 per non-compliant invoice) have been active since April 1, 2026. Force majeure and technical outages remain documented exceptions. Belgium is the first EU country to require Peppol exclusively for B2B.
- What e-invoice formats does Belgium accept?
- Belgium uses Peppol BIS Billing 3.0 (UBL 2.1) as its primary e-invoice format. For B2G submissions, the Mercurius platform accepts Peppol-compliant invoices. Belgium does not have a country-specific CIUS — it follows the Peppol BIS specification directly. This makes Belgium one of the simpler countries for e-invoice compliance if you already support Peppol.
- How does Peppol work for e-invoicing in Belgium?
- Belgium relies heavily on Peppol for e-invoice exchange. All B2B e-invoices must be exchanged via the Peppol network or a compatible platform. Businesses need a Peppol ID (registered via an Access Point provider) and use Peppol BIS Billing 3.0 format. The Mercurius platform serves as the government's Peppol Access Point for B2G invoicing. Belgium's full adoption of Peppol means businesses already on the Peppol network have minimal additional work for compliance.
Have a Belgium e-invoice that came back rejected? Check it here.
Checking is free. The first verified download every 30 days is free. After that €1.90 per invoice, or €9 a month for all of them.