The short answer
In Belgium, a credit note is the corrective document you issue when an invoice you already sent has to be reduced or cancelled: a mistake, a return, a discount granted afterwards, or a cancelled order. Royal Decree No. 1 on VAT (article 12) requires it to refer to the invoice it corrects. When it gives VAT back to the customer, Royal Decree No. 4 (article 4) requires the mention "Btw terug te storten aan de Staat in de mate waarin ze oorspronkelijk in aftrek werd gebracht": VAT to be repaid to the State to the extent it was originally deducted. Since 1 January 2026, a credit note correcting a structured e-invoice must itself be structured and sent over Peppol, in the same format as the original. You never delete or renumber the original invoice; you correct it.
Based on Royal Decrees No. 1 and No. 4 on VAT, the FPS Finance e-invoicing FAQ (einvoice.belgium.be) and the Peppol BIS Billing 3.0 specification, read on 1 October 2026. General information, not tax advice.
When you issue a credit note
An issued invoice stays in your outgoing invoices book; any later change goes through a separate document. The common cases:
An error on the invoice. Wrong price, quantity, VAT rate or customer. You credit the wrong invoice in full or in part, and issue a new, correct invoice where needed.
Returned goods. The customer sends back all or part of a delivery. You credit what came back.
A discount granted afterwards. A year-end rebate or a commercial gesture after a complaint. A discount you already know when you invoice belongs on the invoice itself: article 5 of Royal Decree No. 1 lists prompt-payment discounts and price reductions among the invoice mentions.
A cancelled order or contract. The invoice was issued, but the deal fell through. You credit the full amount.
An invoice sent to the wrong company. FPS Finance is explicit: the wrongly sent invoice is still recorded in your books and VAT return, and the amounts are corrected through a corrective document, "in practice: a credit note".
You do not need a credit note for a document that was never an invoice. A pro forma, for example, can simply be replaced. Pro forma and advance invoices explains where that line sits. And a customer who simply does not pay is not a reason to issue a credit note on its own; what to do about an unpaid invoice covers that route.
Mandatory elements of a Belgian credit note
Element | What it means in practice | Source |
|---|---|---|
Date and sequential number | Its own number in a series that identifies it unambiguously, recorded in your outgoing invoices book | Royal Decree No. 1, art. 5 |
Supplier and customer details | Name, address of the registered office and VAT number of both parties, as on the invoice | Royal Decree No. 1, art. 5 |
What is being corrected | Description and quantity of the goods or services concerned | Royal Decree No. 1, art. 5 |
Amounts per VAT rate | Taxable amount, unit price excl. VAT, VAT rate and VAT amount being credited | Royal Decree No. 1, art. 5 |
Reference to the original invoice | The number (and in practice the date) of the invoice being corrected | Royal Decree No. 1, art. 12, para. 3 |
VAT repayment mention | "Btw terug te storten aan de Staat in de mate waarin ze oorspronkelijk in aftrek werd gebracht", when VAT is given back | Royal Decree No. 4, art. 4, para. 1, 3° |
A copy for your records | You keep a copy of every corrective document you issue | Royal Decree No. 1, art. 12, para. 4 |
Structured format (since 2026) | Peppol credit note if the original was a structured e-invoice | FPS Finance e-invoicing FAQ |
How the VAT correction works
On your side as supplier, Royal Decree No. 4 sets the procedure for getting VAT back: you draw up the corrective document stating the amount to be refunded, record it in a register kept for that purpose, and, in the cases of article 79 of the VAT Code, send the customer a duplicate carrying the repayment mention. Article 5 of the same decree sets the timing: the VAT to be refunded is set off against the VAT due in the return for the period in which the right to the refund arose. If you miss that return, you can still make the correction in a return filed before the end of the third calendar year after the year the right arose.
On the customer's side, the mention is the point: they deducted the VAT on the original invoice, and the credit note tells them to give back that deduction, to the extent they took it.
Keep everything: FPS Finance requires you to keep invoices, copies and other documents for 10 years, counted from 1 January of the year after they were issued.
Credit notes under mandatory Peppol e-invoicing
Since 1 January 2026, invoices between VAT-registered businesses established in Belgium must be structured e-invoices, normally sent over Peppol. How Peppol works in Belgium covers who is in scope. For credit notes, FPS Finance's FAQ says: "Any document that modifies the original structured electronic invoice and refers to it specifically and unambiguously is considered to be a structured electronic invoice and is issued in the same format as the original invoice. Credit and debit notes must therefore also be sent via Peppol."
Document type. Peppol BIS Billing 3.0 has a separate credit note message (UBL CreditNote), with type code 381 "Credit note" as the standard choice. Other allowed codes are 81, 83, 396 and 532.
Reference. In the Peppol schema, the reference to the preceding invoice (BillingReference) is optional. Belgian VAT law requires the reference, so fill it in every time.
Old invoices. A 2026 credit note on a 2025 invoice follows the format of the original. For a PDF invoice from 2025, FPS Finance says a PDF credit note is still possible in 2026 if the customer accepts it; a structured one cannot be refused.
Self-billing. Peppol has a separate self-billing credit note type; prior agreement and acceptance of each one are still required.
Receiving the wrong invoice. A company that receives an invoice not meant for it should reject it over Peppol with an Invoice Response, status code "RE". The sender then credits it.
How to check if a Belgian company is on Peppol shows how to confirm a customer can receive.
Credit note or negative invoice?
Belgian VAT law speaks of a corrective document that refers to the invoice it corrects. A credit note is the standard form. Some tools instead issue a new "invoice" with minus amounts. That makes it easy to forget the reference and the repayment mention, and on Peppol the customer's software receives an invoice rather than a credit note. Use the CreditNote document type for corrections.
A negative line on a regular invoice is a different thing. Deducting an advance already invoiced from a final invoice, for example, is part of a new invoice, not a correction of an old one.
Common mistakes
Deleting or reusing the invoice number. An issued invoice stays in your books. Credit it, then reissue.
No reference to the original invoice. Required by law, and the field your customer's accounting uses to match the two.
Forgetting the VAT repayment mention. Check that your credit note template prints it.
A PDF credit note for a Peppol invoice. If the invoice was structured, the credit note must be too.
Crediting the wrong company. A wrong enterprise number routes the invoice, and then the credit note, to another business. Check the customer's KBO and VAT number before the first invoice; how to check a VAT number shows how. Bizzy shows the enterprise number and VAT number from the KBO register for Belgian companies and can complete them in your CRM.
Frequently asked questions
What must a credit note contain in Belgium? The same mentions as an invoice (date, sequential number, both parties' details and VAT numbers, description, taxable amount and VAT per rate), a reference to the original invoice, and, when VAT is given back, the mention "Btw terug te storten aan de Staat in de mate waarin ze oorspronkelijk in aftrek werd gebracht".
Is the VAT mention on a credit note mandatory? Yes, when the credit note gives VAT back to a customer. It comes from article 4 of Royal Decree No. 4 on VAT and tells the customer to repay the VAT to the extent it was deducted.
Do credit notes have to go through Peppol? Yes, when the original invoice was a structured e-invoice. FPS Finance says credit and debit notes are issued in the same format as the original invoice.
Can I cancel an invoice instead of issuing a credit note? No. Once issued and recorded, an invoice stays in your books. You cancel it with a credit note for the full amount and issue a new invoice if needed.
Photo: the abbey ruins of Villers-la-Ville, EmDee, CC BY-SA 4.0, via Wikimedia Commons