BR-02:Invoice must have an invoice number
Every invoice must contain a unique invoice number (ID) to identify the document.
Engine Classification
Business data required · Explicit input workflow · No assumptions made
Required input: Invoice Number
What is BR-02?
BR-02 is a fatal validation rule defined in the EN 16931 specification. It validates the ID element under Invoice in the UBL invoice XML.
When this rule fires, the invoice is non-compliant and will be rejected by Peppol access points and national validation services. The sending system receives a rejection response and the invoice does not reach the buyer.
Target path: XPath: /Invoice/cbc:ID
Why This Error Matters
Invoice rejected. Cannot be processed for payment or tracked in accounting systems.
BR-02 is a hard failure. Invoices that trigger this rule are rejected at the access point and never reach the recipient. In Peppol networks, this means your sending system receives an MLR (Message Level Response) with a rejection status. The invoice must be corrected and re-sent, adding delay to your payment cycle.
Validator Behavior
- ·Causes invoice rejection
- ·Error returned: BR-02
- ·Specification: EN 16931
How to Fix It
Generate invoice number
Use your invoicing system sequence or create a unique identifier
Add to invoice
Insert the ID element with your invoice number
Ensure uniqueness
The number should be unique within your organization
Before / After
<cbc:ID></cbc:ID>
<cbc:ID>INV-2026-001234</cbc:ID>
Technical Reference
XPath: /Invoice/cbc:IDCode Example
<cbc:ID>INV-2024-001234</cbc:ID>Common Causes
- ·Draft invoice exported before number was assigned
- ·Invoice number field empty or null in source system
- ·Export template missing invoice number (ID) mapping
- ·Sequential numbering system not configured in ERP
- ·Manual invoice creation without assigning number
Seeing this in production? The API handles BR-02 automatically. See the fix response →
ERP-Specific Causes
Commonly Seen In
Frequently Asked Questions
Every invoice must contain a unique invoice number (ID) to identify the document.
Add a unique invoice number to the ID element. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.
Yes, BR-02 is a critical error that will cause invoice rejection. It must be fixed before submission to ensure your invoice is accepted by the recipient's system.
Many instances of BR-02 can be automatically corrected using Invoice Navigator's Fixer tool. Upload your invoice and the tool will identify and fix common issues, including invoice must have an invoice number.
BR-02 is commonly seen in exports from All invoicing software. These software packages sometimes generate invoices that need adjustment to meet full compliance standards.
See Also
Related Errors
Last updated: 27 February 2026
Handle BR-02 Automatically in Your Pipeline
The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.