E-invoicing in Belgium from 2026: what every business needs to know

Belgium became one of the first EU member states to make structured B2B e-invoicing mandatory for all VAT-registered businesses. The obligation took effect on 1 January 2026, and it applies to every company that issues or receives invoices in Belgium, regardless of company size or sector. If you trade with Belgian partners, this affects you even if you are based elsewhere in the EU.

This post walks through what the mandate requires, who it covers, what Peppol and Factur-X are, what happens if you do not comply, and what the legal proof layer looks like once you have the format right.

What the mandate requires

Belgian law now requires every B2B invoice to be:

Structured. The invoice must be machine-readable, meaning the data fields (VAT number, line items, totals, payment terms) are in a defined XML schema, not just rendered as visual text inside a PDF.
Sent over Peppol. The invoice must travel through the Peppol four-corner network. Emailing an XML file does not satisfy the mandate. Both parties must have an Access Point.
Compliant with Peppol BIS Billing 3.0. This is the document specification used across most of Europe: UBL XML with specific mandatory elements.

A plain PDF invoice, even one with a pretty layout and all the right figures, is no longer compliant for Belgian B2B transactions. Neither is a CSV export or an EDI message in a legacy format.

Who it applies to

The mandate covers every Belgian VAT-registered business issuing invoices to other Belgian VAT-registered businesses. That includes:

Self-employed individuals registered for VAT
SMEs
Large enterprises
Foreign companies with a Belgian VAT registration

It does not currently cover B2C transactions (invoices to private individuals) or transactions where the customer is not registered for VAT in Belgium.

If you are a non-Belgian business invoicing a Belgian B2B customer, you need to be reachable on Peppol because your customer is obligated to receive invoices that way.

The Peppol network: a brief explanation

Peppol stands for Pan-European Public Procurement On-Line. It started as a procurement network for government contracts and has become the de facto B2B invoicing backbone across Europe.

Peppol uses a four-corner model:

Corner 1: you (the sender), connected to your Access Point
Corner 2: your Access Point, which routes the document
Corner 3: your trading partner’s Access Point, which receives it
Corner 4: your trading partner (the receiver)

You do not connect directly to the Peppol network. You connect via a certified Access Point provider, which handles the routing. Most cloud accounting platforms (Exact, Twinfield, Billit, Yuki, and others) now offer Peppol connectivity built in or as an add-on.

To receive invoices, your VAT number must appear in the Peppol Directory, the public registry of all reachable parties. If a business looks you up and you are not listed, they cannot send you a compliant invoice.

Factur-X and ZUGFeRD: the hybrid format

Peppol transmits UBL XML. That works well for machine-to-machine processing, but UBL XML on its own is not human-readable in any practical sense. This is where Factur-X (and its German counterpart ZUGFeRD) comes in.

Factur-X is a hybrid format: a PDF/A-3 file that embeds the CII XML invoice data as a structured attachment. Open it in any PDF viewer and you see a normal-looking invoice. Open it in an accounting system and you can extract the machine data directly. Both representations are bit-identical to what was transmitted, both are inside a single container.

Belgium’s mandate allows Peppol UBL XML as the transmission format and Factur-X as the archive format. In practice, many businesses use both: Peppol for delivery, Factur-X for the retention copy.

Timeline

Date	Obligation
1 January 2025	Belgian law published, implementation guidance issued
1 January 2026	Mandatory B2B e-invoicing via Peppol for all VAT-registered businesses
Ongoing	Tax authority audits and enforcement

There is no revenue-based phase-in. The obligation applied to all sizes from day one.

What you need to do

If you have not already acted:

Register with a Peppol Access Point. Your accounting software may already offer one. If not, standalone Access Point providers operate across Belgium.
Check that your VAT number appears in the Peppol Directory. You can verify this at our Peppol Check tool: paste in your VAT number and we tell you within two seconds whether you are reachable.
Run your key trading partners through the same check. Anyone showing as not reachable needs to register before you can send them a compliant invoice.
Confirm that your software can generate Peppol BIS Billing 3.0 UBL XML, not just a PDF or a legacy EDI format.
Set up compliant archival. Belgian tax law requires invoice retention for seven years. UBL XML alone is often not sufficient for human-readable archival; a PDF/A-3 copy satisfies both requirements simultaneously.

Penalties for non-compliance

The Belgian tax authority (FPS Finance) can apply penalties for non-compliant invoicing. Under Belgian VAT law, an invoice that does not meet the legal form requirements can be treated as if no invoice was issued, which means the associated VAT deduction is at risk for the buyer.

Practically, this means:

Buyers can refuse non-compliant invoices
VAT deductions based on non-compliant invoices may be disallowed during an audit
Repeated non-compliance can trigger administrative fines

The focus in the first months of 2026 has been on facilitating transition rather than immediate enforcement, but that window closes as the year progresses.

The legal proof gap

Getting the format right is necessary but not sufficient. The deeper question is: can you prove, years from now, that the invoice you archived is identical to what was sent, and that it existed on the date you claim?

This is where the legal proof layer matters. Two mechanisms close the gap:

RFC 3161 timestamps bind a cryptographic hash of your document to a signed timestamp from a trusted authority. If a tax inspector or court challenges whether an invoice was issued on a particular date, the timestamp is evidence they cannot easily dispute. Belgium’s archival requirements do not mandate RFC 3161 explicitly, but several sectors and contract frameworks do, and the evidentiary value is well recognised in Belgian law.

Chain of custody means you can show an unbroken record from generation to archival: who created the document, when, which processing steps it passed through, and that none of those steps altered the content. SealDoc produces an evidence pack for every processed invoice that includes the original file, the converted PDF/A-3, the structured XML, the RFC 3161 token, and a manifest hash file. Any of those elements can be verified offline.

Ready to check your Peppol status?

The fastest action you can take right now is to verify that you and your trading partners are reachable on Peppol. Our Peppol Check tool looks up any EU VAT number in the live Peppol Directory and tells you whether the party is registered, which document types they accept, and what they need to do to get compliant if they are not.

No account required. Paste the VAT number, get the answer.