`BR-21`

EN 16931 · validation rule

EN 16931Error

An invoice line has no line identifier (BT-126). Each cac:InvoiceLine/cbc:ID / ram:AssociatedDocumentLineDocument/ram:LineID must carry a unique, non-empty value (e.g. 1, 2, 3).

Field: lines[].id (BT-126)
Rule set: EN 16931
Rule-set version: EN 16931 validation artefacts 1.3.17 · in force since 2026-10-13 · Rule-set changelog
Who has to fix it: The sender

This is a property of the file you received, so it cannot be corrected on your side without changing the document — ask the supplier to reissue it.

Check your own invoice

Drop the file that failed. We parse it, run the official rule sets against it and list every finding with a fix — 20 invoices per day, no key, nothing stored.

Open the live demo

Same explanation over the API: GET /v1/rules/BR-21?lang=en