10 min read · Updated 8 May 2026

Belgium B2B E-Invoicing 2026: Peppol-Only and What It Means for Foreign Sellers

Belgium's mandatory B2B e-invoicing went live on 1 January 2026. The Belgian model is the cleanest of the European 2026 cohort: no central clearance platform, no national XML schema, no real-time validation step. Just structured invoices on the Peppol BIS 3.0 standard, exchanged directly between buyer and seller through the Peppol network. The simplicity is deliberate, and four months in, the rollout has been smoother than Italy's, France's pilot, or Poland's first weeks. Here is how the Belgian model works, when foreign sellers are inside the mandate, and what is still coming in 2028.

What changed on 1 January 2026

Three obligations took effect for VAT-registered Belgian-established businesses:

  1. Issue structured e-invoices for all domestic B2B transactions.
  2. Receive structured e-invoices through a Peppol access point.
  3. Stop accepting PDF, Word, or paper invoices as the primary legal document for domestic B2B (except where both parties have explicitly agreed to derogate using EN 16931).

Out of scope: B2C transactions, B2G transactions (which already had their own Peppol obligation under Mercurius since 2024), and intra-EU and cross-border B2B transactions to or from Belgium without a fixed establishment in scope.

The four-month tolerance window

Belgium followed the now-standard pattern of legislating a soft enforcement period. From 1 January to 31 March 2026, no sanctions applied to e-invoicing infringements, provided the taxpayer could demonstrate having taken reasonable and timely steps to comply. The window has now closed; from 1 April 2026 onward, formal penalties for non-compliance apply on the standard VAT-administration framework.

The grace period was useful but largely under-used. Most Belgian businesses that were going to be ready by 1 April were ready on 1 January, because the Peppol model is a configuration job rather than a data-model rebuild.

The Peppol-only model in plain English

Belgium's choice was architecturally interesting: rather than build a central clearance platform like Italy's SDI or Poland's KSeF, or a hybrid private-platform model like France's PA/PPF, Belgium standardized on the existing pan-European Peppol network. The mechanics:

The simplicity has a trade-off: Belgium gets fewer real-time fraud-detection benefits than KSeF or SDI provide, but the implementation cost for taxpayers is dramatically lower. The expected real-time data layer arrives with e-reporting in January 2028.

The EN 16931 derogation

Belgium did not lock taxpayers into Peppol BIS. The law allows derogation from Peppol BIS provided two conditions are met:

  1. Both parties agree in advance to derogate.
  2. The invoices issued conform to EN 16931 (the underlying European semantic standard) and CEN/TS 16931-2 in the most current version.

In practice, this allows two trading partners with sophisticated EDI integrations to keep using their existing UBL or CII flow, provided it is EN 16931 compliant. The derogation does not allow PDF or paper.

For most Belgian businesses, sticking with Peppol BIS over Peppol is simpler, cheaper, and gets you cross-border interoperability for free. The derogation is mainly used by large multinationals with established EDI relationships and by industry-specific standards (some logistics and energy verticals).

Hermes: the government inbox

The FOD Financien operates Hermes, a free-of-charge Peppol access point that every Belgian VAT-registered business can use as a fallback inbox. Hermes ensures that even small businesses without an ERP or tax software have a way to receive Peppol e-invoices on day one.

Hermes has limits. It is a receive-only service for small and very small businesses. It does not handle outbound invoicing, so if you need to issue Peppol invoices you need a private access point or an ERP with built-in Peppol capability. It is also not a long-term solution for any business with material invoice volume; the user experience is comparable to a generic government portal.

Practical advice: if you are a small Belgian business with low invoice volume, Hermes plus a basic accounting tool with Peppol-out is enough. If you have material AP volume or any ERP integration, contract with a private Peppol access point provider (Edicom, Sovos, Pagero, Tradeshift, Babelway, and others have Belgian offerings).

Foreign sellers: where the obligation does and does not bite

Belgium followed the same fixed-establishment principle as Poland and France:

The fixed-establishment test is the EU VAT case-law standard: personnel and technical resources, sufficient permanence, and actual involvement in the underlying supply.

How the rollout has actually felt

Four months into Belgium's mandate, the issues that have surfaced are far smaller than what other countries have lived through:

1. Counterparty Peppol IDs

Every Belgian VAT-registered business should be discoverable in the Peppol Service Metadata Locator (SML) directory. Onboarding lag in early 2026 meant some smaller businesses did not appear in the directory until February or March, causing temporary delivery failures. By April this was largely resolved.

2. Mass-onboarding for AR and AP

The Peppol model requires you to discover your customers' Peppol participant IDs before you can send. Bulk look-ups against the directory exposed AR teams to a mapping problem most had not anticipated. The fix is straightforward (look up customers' Peppol IDs at onboarding, store them on the customer master) but takes one or two cycles to operationalize.

3. Credit notes and references

Peppol BIS handles credit notes through a specific document subtype with explicit linkage to the original invoice. ERPs that issued a corrective invoice with a fresh number need to switch to the credit-note pattern. This is a small change but a uniform one.

4. Format conversion in mixed-vendor flows

Belgian businesses that have one customer demanding the EN 16931 derogation route (custom UBL profile) and another requiring strict Peppol BIS find themselves running two outbound flows. Most Peppol access point providers handle this transparently, but it is worth confirming during procurement.

5. AP automation gains

Counterintuitively, the rollout has been a net positive for AP teams in many companies. Structured invoice ingestion (versus PDF OCR) is materially more accurate, and three-way matching against POs runs cleaner. Companies that invested in AP automation alongside the mandate are seeing the productivity payback faster than expected.

What's coming in 2028: e-reporting (DRR)

Belgium's plan is to layer a near-real-time e-reporting (DRR: Dispositif de Reporting des Données de Transaction, or Digital Reporting Requirement) on top of the e-invoicing infrastructure from 1 January 2028. The design is still being finalized, but the expected shape is:

The 2028 layer is also Belgium's path to ViDA alignment. By ViDA's 1 July 2030 cross-border B2B mandate, Belgium will already have most of the data infrastructure in place.

Action checklist

  1. If you are a Belgian-established business: by April 2026 you should already be live. If not, prioritize a Peppol access point procurement immediately. The mandate is in force, and the tolerance window has closed.
  2. Verify Peppol participant IDs for your top 100 customers and suppliers. Store them on the master record. Run periodic sweeps against the SML directory.
  3. Migrate corrective invoice flows to use the Peppol BIS credit-note subtype with explicit reference to the original invoice ID.
  4. Decide on EN 16931 derogation with key high-volume trading partners only if both sides have material EDI investment that justifies the carve-out. For everyone else, default to Peppol BIS.
  5. If you are a foreign seller: document your no-fixed-establishment analysis if you have only a Belgian VAT registration. Confirm with your Belgian B2B customers that they accept EN 16931 invoices outside Peppol; many will request Peppol delivery anyway.
  6. Plan for 2028 e-reporting. The DRR layer requires richer transaction data than the current e-invoice flow. Build a roadmap now even though the exact specifications are still maturing.

How Belgium fits with the rest of Europe in 2026

Belgium is one piece of a wider 2026 European e-invoicing wave. Several mandates went live or take effect this year:

For the full picture, see our e-invoicing requirements by country tracker.

Frequently asked questions

When did Belgium's e-invoicing mandate take effect?

1 January 2026. A four-month tolerance window suspended sanctions until 31 March 2026.

What format does Belgium require?

Peppol BIS Billing 3.0 over the Peppol network is the default. Derogation to other EN 16931 compliant formats is allowed if both parties agree.

Do foreign sellers have to use Peppol for invoices to Belgian customers?

Only if they have a Belgian fixed establishment that participates in the supply. Foreign companies VAT-registered in Belgium for distance sales without an establishment are not in scope.

What is Hermes?

The FOD Financien's free Peppol access point service. A receive-only fallback for small Belgian businesses that have not yet contracted a private access point.

What's coming in 2028?

E-reporting (DRR): near-real-time transaction-level data flows to the tax authority on top of the existing Peppol infrastructure, with pre-filled VAT returns expected to follow.

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