What it means
The rule checks that the invoice or credit note has no ext:UBLExtensions element at the top of the file. UBL offers this element so that software can add its own custom data next to the standard fields. EN 16931 gives such data no meaning.
Why it matters
EN 16931's UBL rules recommend leaving out the document-level extensions block, regardless of what it contains.
How to fix it
Delete the ext:UBLExtensions element directly under the invoice or credit note root, including everything inside it. If the extension carried information you need to keep, put it in an appropriate standard field instead, such as the invoice note or an attachment. Export again and 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 extensions 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-001 still fails, and which other rules do.
Related rules
- UBL-CR-002 The UBL version should be 2.1 if given
- UBL-CR-003 The file should not contain a profile execution ID
- UBL-CR-004 The file should not contain a copy indicator
- UBL-CR-005 The file should not contain a document UUID
- UBL-CR-006 The file should not contain an issue time
- UBL-CR-007 The file should not contain a pricing currency code