Reference

BR-02 Invoice number is required

An invoice shall have an Invoice number (BT-1) that uniquely identifies the document for the issuer.

This is an EN 16931 core rule. The invoice number is the main reference for reconciliation, payment matching and audit. BR-02 checks that the number is not empty: the error usually comes from an export that writes an empty ID, for example for a draft that has not been numbered yet. In CII, BT-1 is rsm:ExchangedDocument/ram:ID.

Solution

Populate cbc:ID with the sequential invoice number used in your accounting system; it must not be empty.

Quick actions

Validate XML Convert invoice

Valid Examples

BT-1 = RE-2024-0001 — a non-empty unique document number

Invalid Examples

cbc:ID is present but empty (<cbc:ID></cbc:ID>); in UBL a missing cbc:ID is already an XML schema error

Code Examples

Valid XML

<cbc:ID>RE-2024-0001</cbc:ID>
<cbc:IssueDate>2024-05-01</cbc:IssueDate>

Invalid XML

<cbc:CustomizationID>urn:cen.eu:en16931:2017</cbc:CustomizationID>
<cbc:ID></cbc:ID>
<cbc:IssueDate>2024-05-01</cbc:IssueDate>

Affected Fields

BT-1 Invoice number

Validation Tools

Official KoSIT Validator

Run the official KoSIT validator with the XRechnung configuration to check EN 16931 and XRechnung rules.

Convert PDF to XRechnung

Find validation errors during conversion and review each correction.