What it means
The rule warns if cac:DocumentReference inside cac:InvoiceLine or cac:CreditNoteLine contains the free-text element cbc:DocumentType. It does not check cbc:DocumentTypeCode, used for document type code 130, or the invoiced object identifier (BT-128) in cbc:ID.
Why it matters
EN 16931 does not use a free-text document type in a line document reference.
How to fix it
Open the line in your invoicing software and look at the object or document reference fields. Keep the identifier and document type code 130, and clear the extra type text. In the XML, delete cbc:DocumentType from cac:DocumentReference inside cac:InvoiceLine (cac:CreditNoteLine in a credit note), and keep cbc:DocumentTypeCode. Recheck the file.
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 InvoiceLine DocumentReference DocumentType 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-537 still fails, and which other rules do.
Related rules
- UBL-CR-538 A line document reference should not carry an XPath
- UBL-CR-539 A line document reference should not carry a language
- UBL-CR-540 A line document reference should not carry a locale code
- UBL-CR-541 A line document reference should not carry a version
- UBL-CR-542 A line document reference should not carry a status code
- UBL-CR-543 A line document reference should not carry a description