BR-23:Missing unit of measure code
Each Invoice line shall have an Invoiced quantity unit of measure code (BT-130). This identifies the unit of measure for the invoiced quantity using UN/ECE Recommendation 20 codes.
Engine Classification
Auto-fix: Default to "C62" (unit/piece) which is the standard catch-all unit code. Can also derive from common text patterns like "hours"→"HUR", "kg"→"KGM".
What is BR-23?
BR-23 is a fatal validation rule defined in the EN 16931 specification. It validates the @unitCode element under InvoicedQuantity 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: cac:InvoiceLine/cbc:InvoicedQuantity/@unitCode
Why This Error Matters
Invoice rejected. Unit of measure is required for price calculation verification.
BR-23 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.
Invoice Navigator can automatically correct this error in your pipeline. The fix is applied with full audit evidence, so your compliance trail remains intact.
Validator Behavior
- ·Causes invoice rejection
- ·Error returned: BR-23
- ·Specification: EN 16931
How to Fix It
Identify the unit
Determine the unit of measure (pieces, hours, kilograms, liters, etc.)
Find the code
Use UN/ECE Rec 20 codes: C62 (piece), HUR (hour), KGM (kilogram), LTR (liter), MTR (meter)
Add unitCode attribute
Add unitCode="C62" (or appropriate code) to the InvoicedQuantity element
Before / After
<cbc:InvoicedQuantity> <!-- @unitCode is missing --> </cbc:InvoicedQuantity>
<cbc:InvoicedQuantity> <@unitCode>valid-value</@unitCode> </cbc:InvoicedQuantity>
Technical Reference
cac:InvoiceLine/cbc:InvoicedQuantity/@unitCodeCode Example
<cbc:DocumentCurrencyCode>USD</cbc:DocumentCurrencyCode>
<cbc:TaxCurrencyCode>EUR</cbc:TaxCurrencyCode>Common Causes
- ·Unit code not mapped in export template
- ·Source uses text descriptions (pieces) not UN/ECE codes (C62)
- ·Default unit of measure not configured in system
- ·Service lines missing unitCode attribute
- ·UnitCode attribute omitted from Quantity element
Seeing this in production? The API handles BR-23 automatically. See the fix response →
Commonly Seen In
Frequently Asked Questions
If VAT accounting is in a different currency, TaxCurrencyCode must be specified.
Add TaxCurrencyCode if VAT is in different currency. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.
BR-23 is a warning that may not always cause rejection, but it indicates a potential compliance issue that should be addressed to ensure full compatibility.
Many instances of BR-23 can be automatically corrected using Invoice Navigator's Fixer tool. Upload your invoice and the tool will identify and fix common issues, including tax currency code when different from document.
BR-23 is commonly seen in exports from Multi-currency invoicing systems. 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-23 Automatically in Your Pipeline
The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.