What it means
For the due date (BT-9), the check counts cbc:PaymentDueDate elements across the document-level payment means blocks (cac:PaymentMeans) of an invoice or credit note and allows at most one. Repeating the same date in several payment means blocks still fails.
Why it matters
EN 16931 allows at most one due date element across the document-level payment means blocks.
How to fix it
In your invoicing software, check whether the due date is repeated in several payment means blocks. If you build the XML yourself, keep at most one cbc:PaymentDueDate across the document-level cac:PaymentMeans blocks and remove any extra occurrences.
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
Due Date shall occur maximum once 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-SR-45 still fails, and which other rules do.
Related rules
- UBL-SR-46 The payment means text can only be given once
- UBL-SR-47 All payment means codes on an invoice must be the same
- UBL-SR-48 Every line must have exactly one VAT category
- UBL-SR-49 The VAT point date code can only be given once
- UBL-SR-50 A line can have only one item description
- UBL-SR-51 An address can have only one third address line