What it means
When an invoice or credit note refers to an earlier invoice, EN 16931 carries only that invoice's number (BT-25) and date (BT-26), in cac:BillingReference/cac:InvoiceDocumentReference. This rule checks that the reference does not also contain cbc:LocaleCode, a code for the language and region settings of the earlier document.
Why it matters
EN 16931 has no field for a locale code in the reference to an earlier invoice.
How to fix it
Remove only cbc:LocaleCode from cac:BillingReference/cac:InvoiceDocumentReference. Keep the earlier invoice number (BT-25) in cbc:ID and any existing invoice date (BT-26) in cbc:IssueDate. You do not need to change your software's general language or regional settings for this check. Check the corrected file again.
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 the BillingReference LocaleCode 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-030 still fails, and which other rules do.
Related rules
- UBL-CR-031 Do not send a version in the earlier invoice reference
- UBL-CR-032 Do not send a status code in the earlier invoice reference
- UBL-CR-033 Do not send a description in the earlier invoice reference
- UBL-CR-034 Do not attach a file to the earlier invoice reference
- UBL-CR-035 Do not send a validity period in the earlier invoice reference
- UBL-CR-036 Do not send an issuer party in the earlier invoice reference