Belgium’s B2B E-Invoicing Mandate 2026: Deadlines, Penalties & Who Must Comply

Belgium’s B2B e-invoicing mandate requires every VAT-registered business established in Belgium to send and receive structured electronic invoices for domestic business-to-business transactions. The rule has applied since 1 January 2026, and full enforcement began on 1 April 2026. Invoices must use the Peppol BIS Billing 3.0 format and travel over the Peppol network. A PDF emailed to a business customer no longer counts as a compliant invoice.

Belgium e-invoicing at a glance

What the Belgian mandate requires

The Belgian mandate requires structured electronic invoices — machine-readable data files, not PDFs or scans — for all domestic B2B transactions between VAT-registered businesses. A structured invoice carries its data in a fixed digital format that the recipient’s software can read and process automatically, with no retyping.

The required format is Peppol BIS Billing 3.0, built on UBL 2.1 syntax and aligned with the European standard EN 16931. Invoices move through the Peppol network rather than by email.
If you want the full background on the network itself, see our guide to what Peppol is and how the network works.

The practical change is simple but strict: a PDF attached to an email is no longer a valid B2B invoice in Belgium. Belgium did not build a central government portal for this. Instead it relies on Peppol’s four-corner model, where certified Access Points exchange invoices on behalf of the sender and receiver.

What a compliant e-invoice must include

A compliant Belgian e-invoice must carry the same legal details as a paper invoice, but as structured data fields the recipient’s software can read. Miss a required field and the invoice can be rejected or fail to send, so it is worth knowing the list before you switch.

Every structured B2B invoice needs:

• Invoice number and date — a unique identifier and the issue date
• Your company details — name, address, and VAT or CBE number
• The recipient’s details — company name and CBE number, which is required for Belgian B2B
• Line items — each with a description, quantity, unit of measure, and price
• A VAT breakdown — rate and amount per VAT category
• Payment method, currency, and due date — typically EUR for Belgium

Two fields trip people up most often: the recipient’s CBE number and a unit of measure on every line. Both are mandatory in the structured format even though paper invoices often skipped them. There is also a new rounding rule from 1 January 2026: rounding is allowed only on the total VAT amount per rate, not on individual line items. If you want the wider context, our guide to the essential invoice elements covers the anatomy of an invoice in full.

Key dates and rollout timeline

Belgium’s B2B e-invoicing obligation took effect on 1 January 2026, and penalties have been enforced since 1 April 2026 after a three-month tolerance period. The business-to-government (B2G) side came first and was phased in by region over several years.

Who must comply — and who is exempt

Every VAT-registered business established in Belgium must comply with the B2B e-invoicing mandate, regardless of company size or turnover. That includes freelancers, sole traders, SMEs, and large companies. If you issue an invoice to another Belgian VAT-registered business, it has to be a structured Peppol invoice.

You must also be able to receive structured invoices, not just send them. The exemptions below are narrow and tied to specific tax statuses.

If you are unsure which invoices are caught, the deciding factors are the supplier, the customer, and the transaction. When all three point to domestic Belgian B2B, the structured-invoice rule applies. For a refresher on the documents themselves, see our overview of the different types of invoices.

Penalties for non-compliance

Businesses that fail to issue compliant e-invoices face administrative fines starting at €1,500 and rising to €5,000 for repeated offences. The fines escalate with each new offence.

A minimum interval of three months applies between penalties, so a business cannot be fined repeatedly within the same quarter for the same unresolved issue. There is a second, quieter risk: an improperly formatted invoice can lead to the denial of VAT deduction for the recipient — which means your customers have a direct reason to insist on compliant invoices from you.

Late or disputed invoices also slow down payment. Sending compliant, structured invoices from day one keeps your invoice payment terms enforceable, and pairing them with automatic payment reminders keeps your cash flow predictable.

The 120% tax deduction

Belgian SMEs and self-employed people can deduct 120% of eligible e-invoicing costs from taxable income for tax years 2024 through 2027. Eligible costs include invoicing software, Access Point subscriptions, and implementation consultancy.

In practice this means the cost of getting compliant is partly offset by a tax break, for a limited window. It is worth factoring in before the deduction period closes.

Foreign and multi-country businesses

Foreign businesses must follow the Belgian mandate only when they have a fixed establishment in Belgium; a Belgian VAT number on its own does not trigger the obligation. A non-resident company with only a Belgian VAT registration falls outside the 2026 scope.

If you run a Belgian entity as part of a multi-country group, that entity must issue and receive structured Peppol invoices for its domestic B2B trade like any local business. And because Peppol is an international network, sending a compliant invoice to a Belgian customer works the same way whether you are based in Brussels or abroad — you connect once through a certified Access Point and reach any participant on the network.

Hermes is gone — what to use now

Belgium decommissioned its free government Hermes platform on 31 December 2025, so businesses that relied on it now need a Peppol connection through their own invoicing software. Consultation-only access remained until 31 March 2026, but Hermes no longer sends or receives invoices.

Hermes was always meant to be temporary. It was a government-run bridge that received Peppol invoices on behalf of companies not yet connected, converted them to PDF, and emailed them out. After a market review found that private Peppol solutions had matured, the government retired the bridge and now expects businesses to use a certified provider.

If you were depending on Hermes, the practical step is to choose Peppol-capable invoicing software that registers you on the network and sends structured invoices for you. That is exactly the gap a modern invoicing app fills.

How to comply without an IT project

Staying compliant with the Belgian mandate only requires a Peppol-capable invoicing tool that converts your invoices and sends them over the network for you. You do not need a developer, an EDI integration, or a separate Access Point subscription.

This is where Billdu’s Peppol e-invoicing for Belgium fits. You create an invoice the way you always have, and the app converts it to Peppol BIS Billing 3.0 and delivers it through a certified Access Point in seconds. Registration on the Peppol network uses your CBE number and completes almost instantly. Corrections go out as compliant e-credit notes linked to the original, and invoices to Belgian government bodies travel through the same flow via Mercurius. You can still send a PDF, email, or link to customers outside Peppol — such as consumers or non-Belgian clients — from the same place.

Beyond the mandate itself, the same app gives you invoice status tracking from sent to paid and lets you accept online payments, so your structured invoices do not just stay compliant — they get paid faster.

If you just need a one-off document while you set up, you can also create a professional invoice for free. For step-by-step instructions on the sending flow itself, see how to send a Peppol invoice.

Methodology and sources

This guide draws only on primary regulatory sources, verified in May 2026. Dates and thresholds for fast-moving mandates change, so we recheck the authority pages on a fixed cadence and update this article when they do.

• European Commission — eInvoicing in Belgium
• FPS BOSA — einvoice.belgium.be
• Law of 6 February 2024 amending the Belgian VAT Code (Art. 53 §2bis)
• Royal Decree on Structured Electronic Invoices (penalties; 120% deduction)
• OpenPeppol — Belgium country profile
• EU Directive 2014/55/EU and the EN 16931 standard