Mandatory legal mentions on Belgian invoices
A practical checklist of required invoice fields under Belgian VAT rules — parties, VAT numbers, dates, totals, VAT breakdown, numbering — and how they appear in structured Peppol invoices.
Updated
- Belgique
Why legal mentions matter
A Belgian invoice is not only a payment request. For VAT-liable businesses, it is an evidence document that supports deduction, reporting, and audit. Missing or incorrect mentions can invalidate VAT recovery for your customer, trigger corrections, or attract scrutiny from the FPS Finance.
Whether you issue a classic PDF or a structured Peppol invoice, the underlying information obligations remain. E-invoicing changes how data travels, not what must be documented.
Supplier and customer (parties)
Every invoice must clearly identify the supplier — the business that performed the supply. At minimum, this means the legal name and full address (street, postal code, city, country). For companies, use the name registered with the Crossroads Bank for Enterprises (CBE), not an informal trading name alone.
The customer must also appear with name and address when the invoice supports a B2B transaction or when VAT treatment depends on the buyer's status. Intra-community supplies, reverse-charge services, and exports often require the customer's VAT identification number on the invoice.
In structured Peppol messages, these appear as AccountingSupplierParty and AccountingCustomerParty blocks with standardized address and identifier fields. Your invoicing software should map your company profile and customer master data into those slots automatically.
VAT identification numbers
The supplier's Belgian VAT number (format BE0xxx.xxx.xxx) must appear on every invoice issued by a VAT-liable business. It links the document to your periodic VAT return and to Peppol participant identity.
The customer's VAT number is mandatory in specific situations: intra-EU B2B supplies of goods, reverse-charge mechanisms, certain construction work, and other cases defined in the VAT Code. When required and absent, the invoice may not support the intended VAT treatment.
On Peppol, VAT numbers travel as endpoint identifiers and as party tax scheme fields. Registration on the network typically uses the same number you print on the PDF.
Description of the supply
Each invoice must describe what was supplied with enough detail to verify the transaction. Line items should state the nature of the goods or services, quantities or units where relevant, and unit prices excluding VAT unless you use tax-inclusive pricing with a clear breakdown.
Vague descriptions ("consulting", "materials") create reconciliation problems for buyers and auditors. Align descriptions with contracts, delivery notes, or project references where practical.
Structured invoices encode this in InvoiceLine elements: item name, quantity, unit of measure, net amount, and tax category per line. Peppol BIS Billing validates that totals roll up consistently from lines to document level.
Dates that must appear
Three dates frequently matter on Belgian invoices:
| Date | Purpose |
|---|---|
| Invoice date | Date of issue; starts payment and prescription clocks |
| Supply / performance date | When goods were delivered or services performed, if different from invoice date |
| Payment due date | When the amount is payable (standard in B2B practice) |
The invoice date and supply date drive VAT period allocation. If you invoice in March for work completed in February, both dates may need to appear so the customer books VAT in the correct period.
In UBL, these map to IssueDate, TaxPointDate or delivery dates, and PaymentDueDate. Missing supply dates on cross-period invoices is a common source of buyer-side adjustments.
Totals and amounts payable
The invoice must show the taxable amount, VAT amount, and total amount payable in a way that leaves no ambiguity. For multiple VAT rates, show subtotals per rate before the grand total.
Amounts are typically expressed in euro for domestic transactions. Foreign currency invoices are permitted in some cases but require clear conversion rules and additional mentions; most Belgian SMEs invoice in EUR.
Structured documents carry LegalMonetaryTotal and TaxTotal aggregates. Peppol receivers often post directly from these fields — errors at header level propagate into accounting without anyone reading a PDF.
VAT breakdown
Belgian invoices must split VAT by rate (21%, 12%, 6%, 0%, exempt, etc.). For each rate applied, show the taxable base and the VAT amount. When an exemption or special regime applies, reference the legal basis in text (for example intra-community supply, export, reverse charge, or small business exemption).
A single lump-sum "VAT: €X" without rate detail is insufficient when multiple rates or regimes appear on one invoice.
In EN 16931 / Peppol BIS, tax categories are coded (S, Z, E, AE, K, etc.) with explicit percentages and bases. Your software should map Belgian rates to the correct category codes so receivers' ERP systems interpret them correctly.
Continuous numbering
Belgium requires unique, sequential invoice numbering without unjustified gaps. The number identifies the document in your records and in your customer's accounts payable. Credit notes use their own continuous series or a clearly distinct sequence, depending on practice and software design.
Renumbering issued invoices, deleting numbers, or reusing numbers after cancellation breaks audit trails. The correct approach is to issue a credit note linked to the original invoice rather than editing history.
Structured e-invoicing makes numbering discipline visible: duplicate IDs, out-of-sequence patterns, and orphaned credit notes are easier for systems and auditors to detect. Treat the invoice number as immutable once the document is sent on Peppol.
Other mentions you will often see
Beyond the core list, Belgian practice commonly includes:
- Invoice number — the unique identifier in your sequence
- Purchase order or contract reference — aids matching, not always legally mandatory but operationally essential
- Payment instructions — IBAN, BIC, structured communication (OGM/VCS) in Belgium
- Legal form and company registration — SA, BV, VZW, etc., sometimes with CBE number
- Special VAT statements — reverse charge wording, export mention, margin scheme, co-contractor rules
- Reduced-rate justification — when a derogation applies to specific goods or services
None of these replace the mandatory core, but they prevent disputes and speed up payment.
Structured Peppol carries the same facts
When B2B structured e-invoicing applies, the Peppol XML (typically UBL under Peppol BIS Billing 3.0) is the authoritative exchange format. It still contains supplier and customer parties, VAT identifiers, line descriptions, dates, monetary totals, and tax breakdowns — as machine-readable fields rather than layout on paper.
A human-readable PDF may accompany the structured file for convenience. Compliance depends on the structured payload meeting EN 16931 semantics and Belgian business rules, not on whether the PDF looks attractive.
Configure your invoicing or access point solution so master data, VAT logic, and numbering rules feed both renderings from a single source. Divergence between PDF and XML is a defect risk.
Practical checklist before sending
- Supplier and customer names and addresses complete
- Correct VAT number(s) for the transaction type
- Clear line descriptions with quantities and net amounts
- Invoice date; supply date if different; due date
- Per-rate taxable bases and VAT amounts; grand total payable
- Next number in your continuous sequence; credit note linked if correcting
- Special regime wording where applicable
- For Peppol: validated XML with matching totals and tax categories
- Legal mentions
Mandatory information that must appear on a VAT invoice under Belgian rules so the document supports tax evidence, deduction, and audit.