Reference · EN 16931

Correcting an invoice you have already issued

You issued an invoice and something on it is wrong. The fix is not an edit; an issued document does not accept one. The standard already has a document type for the correction: a credit note.

EN 16931's invoice type code (BT-3) tells the two apart by value: 380 is an invoice, 381 is a credit note. A credit note is not a note attached to the original invoice — it is a full document in its own right, one that names the invoice it corrects.

Why you cannot just edit it

Once issued, a document cannot be edited — corrections go through a credit note.

Concretely, an attempt to change or remove an issued invoice's lines, parties or totals is refused outright, with a fixed error rather than a partial update, and the document already stored for it (the same bytes, the same SHA-256 hash) is left exactly as it was at issuance. This holds for a credit note exactly as it holds for an invoice. Once either is issued, it is equally out of reach of an edit.

What a credit note is for

The 380/381 pairing is not a convention you have to enforce yourself. An invoice is never permitted to reference a credited invoice, and a credit note is never permitted to omit one. A document that breaks the pairing is refused outright. It is not merely discouraged.

Correcting an issued invoice therefore means creating a new document (a credit note) against the invoice it corrects, then issuing that credit note in its own right. The original invoice is untouched; the credit note is the record of the correction, sitting alongside it rather than replacing it.

What gets checked before a credit note is issued

A credit note can only be drafted against an invoice that is itself issued and owned by the same organisation, and a credit note cannot itself be the target of another credit note — there is no chaining. Before it is allowed to reach issued status, a credit note is also checked against its target: combined with any credit notes already issued against that same invoice, it must not exceed the invoice's total, and every VAT category/rate combination it uses must already appear on the invoice it credits.

What this does not cover

This article does not state what a tax authority requires a business to retain, or for how long. That is a matter of national law. This product does not decide it. It does not say when a correction is legally required rather than merely possible. That judgment belongs to the reader. This text does not make it. And it does not cover transmission: EUInvoice does not send documents over the Peppol network, Poland's KSeF, or France's Chorus Pro / PPF, so issuing a credit note here is a separate question from delivering one through any of those channels.

It also does not cover a credit note split across more than one invoice, a separate "corrective invoice" document type, or an invoice type code other than 380 or 381; this product supports exactly that pair.