What it means
The rule checks every cac:InvoiceLine in a UBL invoice and every cac:CreditNoteLine in a UBL credit note for cbc:PaymentPurposeCode. Payment instructions (BG-16) are at document level; this line element is not the payment reference (BT-83).
Why it matters
EN 16931 does not use a payment purpose code on an invoice or credit note line.
How to fix it
Delete cbc:PaymentPurposeCode from cac:InvoiceLine or cac:CreditNoteLine. If the aim is to tell the buyer what to quote when they pay, use the payment reference (BT-83) for the whole document. 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 PaymentPurposeCode 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-518 still fails, and which other rules do.
Related rules
- UBL-CR-519 A line should not have a free of charge flag
- UBL-CR-520 A line period should not have a start time
- UBL-CR-521 A line period should not have an end time
- UBL-CR-522 A line period should not have a duration
- UBL-CR-523 A line period should not carry a description code
- UBL-CR-524 A line period should not carry a text description