Rules / BR-21 · Markdown

BR-21

EN 16931-1 layer: en16931

Checked against Peppol BIS Billing 3.0 2026.5

What does BR-21 mean? Each Invoice line (BG-25) shall have an Invoice line identifier (BT-126).

Why did my invoice fail BR-21?

Each Invoice line (BG-25) must have an Invoice line identifier (BT-126) that is unique within the invoice. This identifier lets buyers, sellers and systems reference a specific line unambiguously (for matching, disputes and remittance). The rule ensures every line is individually addressable.

Official rule text

Each Invoice line (BG-25) shall have an Invoice line identifier (BT-126).

Common causes

• A cac:InvoiceLine is missing its cbc:ID element.
• Line IDs were duplicated across lines, so at least one line effectively lacks a distinct identifier.
• The ID element was emitted empty because the source line number was null.

How do I fix it?

<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <!-- ... -->
</cac:InvoiceLine>

Related rules

BR-01 · BR-02 · BR-03 · BR-04 · BR-05 · BR-06 · BR-07 · BR-08