What it means
The seller's item identifier (BT-155) is your own article number for the product. In UBL it is cbc:ID inside cac:SellersItemIdentification on the line. EN 16931 treats it as a plain identifier with no scheme. This rule checks that this cbc:ID has no schemeID attribute.
Why it matters
This is a warning. It is still worth fixing when you can.
How to fix it
In your invoicing software, check the article number field of your products and make sure it holds only the number, with no scheme or code type beside it. If the number is a standard code such as a GTIN or an EAN, enter it as the standard item identifier (BT-157), where a scheme is allowed. If you build the XML yourself, delete the schemeID attribute from cbc:ID in cac:SellersItemIdentification.
Once the file is corrected, check it again for free: Validate an invoice against EN 16931
Or fix the invoice in a form and download the corrected file, for 1 credit: Fix a rejected e-invoice
The rule as published
A UBL invoice should not include a Sellers Item Identification schemeID Where this rule applies
| Rule set | Version |
|---|---|
| EN 16931 (UBL) | 1.3.17 |
| EN 16931 (UBL credit note) | 1.3.17 |
| XRechnung 3.0 (UBL) | 3.0.2 |
| XRechnung 3.0 (UBL credit note) | 3.0.2 |
| Peppol BIS Billing 3.0 (invoice) | 2026.5 |
| Peppol BIS Billing 3.0 (credit note) | 2026.5 |
| SI-UBL 2.0 / NLCIUS (invoice) | 2.0.3.13 |
| SI-UBL 2.0 / NLCIUS (credit note) | 2.0.3.13 |
| France CTC (UBL invoice) | 1.4.0-04 |
| France CTC (UBL credit note) | 1.4.0-04 |
| CIUS-RO UBL Invoice 1.0.9 | 1.0.9 |
| CIUS-RO UBL Credit Note 1.0.9 | 1.0.9 |
Check your file
Drop your e-invoice to see whether UBL-CR-668 still fails, and which other rules do.
Related rules
- UBL-CR-669 A price discount must not carry a reason code
- UBL-CR-670 A price discount must not carry a reason text
- UBL-CR-671 A price discount must not carry a multiplier factor
- UBL-CR-672 A credit note's type code must not carry a listID attribute
- UBL-CR-673 An invoiced object reference must not have a description
- UBL-CR-674 The payment card number must not have a scheme attribute