What it means
A Peppol invoice may contain at most one project reference (BT-11) at document level. In UBL it is a document reference with type code 50.
Why it matters
Peppol BIS Billing 3.0 adds this rule to EN 16931 so that every access point and receiver can process the invoice the same way. The sending or receiving access point rejects an invoice that fails it, so it never reaches the buyer.
How to fix it
Keep the one project the invoice belongs to. If you invoice several projects, send one invoice per project, or put the project details in the line descriptions.
The rule as published
Read the rule on the publisher's site
Where this rule applies
| Rule set | Version |
|---|---|
| Peppol BIS Billing 3.0 (invoice) | 2026.5 |
| Peppol BIS Billing 3.0 (credit note) | 2026.5 |
Check your file
Drop your e-invoice to see whether PEPPOL-EN16931-R080 still fails, and which other rules do.
Related rules
- PEPPOL-EN16931-R100 At most one invoiced object per line
- PEPPOL-EN16931-R101 Line document references may only be invoiced objects
- PEPPOL-EN16931-R110 A line period must start within the invoicing period
- PEPPOL-EN16931-R111 A line period must end within the invoicing period
- PEPPOL-EN16931-R120 The line amount should equal quantity times price, plus charges, minus discounts
- PEPPOL-EN16931-R121 The price base quantity must be above zero