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:UUID, a separate identifier for the earlier document.
Why it matters
The EN 16931 UBL rules do not use a UUID in the reference to an earlier invoice.
How to fix it
Remove only cbc:UUID 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. 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 UUID 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-024 still fails, and which other rules do.
Related rules
- UBL-CR-025 Do not send a time of day in the earlier invoice reference
- UBL-CR-026 Do not send a document type code in the earlier invoice reference
- UBL-CR-027 Do not send a document type name in the earlier invoice reference
- UBL-CR-028 Do not send an XPath in the earlier invoice reference
- UBL-CR-029 Do not send a language in the earlier invoice reference
- UBL-CR-030 Do not send a locale code in the earlier invoice reference