What it means
When the seller is Greek, the sixth part of the invoice number (BT-1) must contain something. The test only checks that the part is not empty; it does not require a numeric value or check uniqueness. It applies to invoices and credit notes.
Why it matters
Peppol BIS Billing 3.0 requires a non-empty sixth part in a Greek seller's invoice or credit note number.
How to fix it
Check the sixth part of cbc:ID directly under Invoice or CreditNote and fill it in if it is empty. In the six-part format, this is the part after the fifth vertical bar (|).
Once the file is corrected, check it again for free: Validate a Peppol BIS invoice
Or fix the invoice in a form and download the corrected file, for 1 credit: Fix a rejected e-invoice
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 GR-R-001-7 still fails, and which other rules do.
Related rules
- GR-R-001-6 Greek invoice number: fifth part must not be empty
- GR-R-001-5 Greek invoice number: fourth part must be a document type
- GR-R-001-4 Greek invoice number: third part must be a whole number
- GR-R-001-3 Greek invoice number: second part must be the invoice date
- GR-R-001-2 Greek invoice number: first part must be a valid TIN
- GR-R-001-1 A Greek invoice number must have six parts