Key takeaways
- An invoice already issued is not edited or deleted: it is corrected by a separate document.
- Under Belgian law that document is the corrective document, which must reference the original invoice unambiguously.
- To reduce or cancel, you issue a credit note; to add a missing amount, an additional invoice.
- In B2B from 1 January 2026, the correction also travels as a structured document over Peppol.
A mistake slips into an invoice already with the customer: wrong amount, incorrect VAT rate, a missing line. The natural reflex is to reopen the document and fix it. In Belgium, that is exactly what you should not do. An issued invoice is part of your accounts and audit trail; it is corrected by a second document, the corrective invoice, which references the original without ever erasing it. With the B2B e-invoicing mandate on 1 January 2026 (law of 6 February 2024), this correction becomes structured too.
This article explains what the corrective invoice covers in Belgium, how to choose between a credit note and an additional invoice, and what e-invoicing changes for this everyday task.
The corrective invoice, a document that adds to the original
Belgian VAT rules do not recognise "editing" an issued invoice: they recognise the corrective document. According to the FPS Finance, it is any document that changes something in an original invoice and forms a whole with it, provided it refers to that invoice specifically and unambiguously. In other words, the correction does not overwrite the invoice: it attaches to it.
Two practical consequences follow. First, the original invoice stays as it is in your books, with its number and date. Second, the corrective document need not repeat every mandatory particular of an invoice: in principle it is enough to correct or complete the wrong or missing particulars, as long as the reference to the original invoice is clear.
The term "corrective invoice" is common in business language, but it actually covers several distinct documents depending on the direction of the correction. That choice shapes everything else.
Credit note or additional invoice: choose by the direction of the correction
The decisive question is simple: does the correction lower or raise the amount invoiced? The answer determines the document to issue.
When you need to reduce or cancel the invoice (amount too high, cancelled service, returned goods, discount granted after the fact), the corrective document takes the form of a credit note. This is the most frequent case, covered in detail in Electronic credit note: when and how to issue one.
When, on the contrary, an amount was under-billed (a forgotten quantity, a discount wrongly applied, a rate set too low), the correction is made through an additional invoice: a new invoice, with its own number, billing the extra amount due and referencing the original invoice.
| Credit note | Additional invoice | |
|---|---|---|
| Corrects downward or cancels | ||
| Corrects upward (missing amount) | ||
| Carries its own sequential number | ||
| References the original invoice | ||
| CreditNote document on Peppol |
In both cases the logic is the same: a separate, numbered document that points to the corrected invoice. What changes is the sign of the transaction and the type of document.
The special case of an invoice not yet sent
As long as an invoice has not been sent to the customer or recorded, it stays editable: it is still a draft. In an invoicing tool, a document in "draft" status can be corrected freely because it has no evidential value yet and no place in the invoice sequence.
The switch happens at issuance. Once the invoice is finalised, numbered and sent, it leaves the draft state and can only be corrected through a corrective document. This is why sequential numbering matters: an allocated number is not reused, and a "gap" in the series must be explainable. The detail of this rule is in Sequential invoice numbering in Belgium.
Reflexes before correcting an invoice
Check the document status
A draft is edited; an issued invoice is corrected by another document.
Identify the direction of the correction
Downward: credit note. Upward: additional invoice.
Reference the original invoice
Number and date of the corrected invoice, unambiguously.
Adjust the VAT
Carry the effect of the correction into the VAT return for the period.
VAT: a correction that flows into the return
A corrective document that touches VAT does not stop at the customer: it flows into your VAT return. A credit note that reduces the taxable base lowers the VAT due, and an additional invoice raises it. The correction relates to the period in which the corrective document is drawn up, under the FPS Finance rules.
When the credit note corrects VAT, Belgian rules provide for a mention inviting the customer to repay to the State the VAT they had initially deducted. The exact wording and the arrangements are to be checked with the FPS Finance; the aim is for the correction to be symmetrical on the issuer's and the recipient's side.
What e-invoicing changes on 1 January 2026
From 1 January 2026, Belgian VAT-registered businesses exchange their B2B invoices as structured documents, by default over the Peppol network and no longer as PDFs. The correction follows the same route: it too becomes a structured document.
In concrete terms, the credit note is the CreditNote document of the Peppol BIS Billing 3.0 profile, sent to the customer through their access point just like the invoice. An additional invoice is a new structured invoice. You do not handle these formats: a compliant tool produces the right corrective document, links it to the original invoice and routes it.
Correct your invoices without breaking the audit trail
YouInv issues your credit notes and additional invoices, links them to the original invoice and sends them over Peppol in a few clicks.
The reflex to keep
Faced with an error on an issued invoice, the question is not "how do I reopen the document" but "which corrective document do I issue". Downward, a credit note; upward, an additional invoice; in both cases, a clear reference to the original invoice and a VAT adjustment. The original invoice stays intact, the correction is traced, and the accounts stay auditable.
Further reading
- Electronic credit note: when and how to issue one: the most common corrective document, in detail.
- Mandatory invoice particulars in Belgium: what an invoice carries, and therefore a correction.
- Sequential invoice numbering in Belgium: why an issued number is not reused.
The reference source prevails: the European Commission's eInvoicing in Belgium page.
What is a corrective invoice?
A corrective invoice is a document that fixes an invoice already issued, without replacing or deleting it. In Belgium, VAT rules speak of a corrective document: any document that changes the original invoice and forms a whole with it, provided it refers to that invoice specifically and unambiguously. The credit note is its most common form.
Can you edit an invoice you have already sent in Belgium?
No. An invoice sent to the customer is not edited or deleted: it stays in your books and its sequential number cannot be reused. The correction always goes through a separate document that references the original invoice, a credit note to reduce or cancel, an additional invoice to add a missing amount.
What is the difference between a corrective invoice and a credit note?
A credit note is one type of corrective document: it reduces or cancels an invoice. Corrective invoice is a broader term covering every way of fixing an issued invoice, including the additional invoice when an amount was under-billed.
How do you correct an invoice under the 2026 mandatory e-invoicing rules?
From 1 January 2026, B2B invoices between Belgian VAT-registered businesses travel as structured documents over Peppol. The correction follows the same route: the credit note is the CreditNote document of the Peppol BIS Billing 3.0 profile, sent to the customer through their access point, and an additional invoice is a new structured invoice.
Must a corrective invoice reference the original invoice?
Yes. The core rule of the corrective document is the specific, unambiguous reference to the invoice being corrected: its number and date. That link ties the correction to the original transaction and enables the VAT adjustment.
