BR-CL-21:Invalid product identifier scheme
A line item's standard product identifier uses an invalid scheme code. The most common standard identifier is a GTIN (barcode number), which should use scheme code 0160. Other valid schemes include ISO 6523 ICD codes for industry-specific numbering systems.
Engine Classification
Maps common invalid scheme identifiers to valid ISO 6523 ICD codes (e.g. GTIN → 0160)
Confidence: 85% · Applied automatically in pipeline
What is BR-CL-21?
BR-CL-21 is a fatal validation rule defined in the EN 16931 specification. It validates the @schemeID element under StandardItemIdentification > ID 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/cac:Item/cac:StandardItemIdentification/cbc:ID/@schemeID
Why This Error Matters
Invoice rejected. Product identifiers must be properly schemed for matching.
BR-CL-21 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-CL-21
- ·Specification: EN 16931
How to Fix It
Identify the product number type
Is this a GTIN/EAN barcode number? If so, the correct scheme is 0160.
Set the correct scheme
Update the schemeID attribute to the correct ISO 6523 ICD code. GTIN = 0160 is the most common.
Verify the number
Make sure the identifier value itself is correct for the chosen scheme (e.g. GTIN should be 8, 12, 13, or 14 digits).
Before / After
<Invoice> <!-- Issue: Item standard identifier scheme identifier MUST belong to th --> </Invoice>
<Invoice> <!-- Issue resolved per EN 16931 --> </Invoice>
Technical Reference
cac:InvoiceLine/cac:Item/cac:StandardItemIdentification/cbc:ID/@schemeIDCommon Causes
- ·SchemeID set to 'GTIN' instead of '0160'
- ·ERP system uses internal scheme codes
- ·SchemeID attribute missing entirely
Seeing this in production? The API handles BR-CL-21 automatically. See the fix response →
Commonly Seen In
Frequently Asked Questions
TaxExemptionReasonCode must be from VATEX list.
Use valid VATEX code like VATEX-EU-AE, VATEX-EU-G, etc. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.
Yes, BR-CL-21 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-CL-21 can be automatically corrected using Invoice Navigator's Fixer tool. Upload your invoice and the tool will identify and fix common issues, including invalid vat exemption reason code.
See Also
Related Errors
Last updated: 27 February 2026
Handle BR-CL-21 Automatically in Your Pipeline
The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.