What it means
When the seller is Greek, the fifth part of the invoice number (BT-1) must contain something. The test only checks that the part is not empty. It does not check what is in it. It applies to invoices and credit notes.
Why it matters
An empty part leaves the invoice number incomplete.
How to fix it
Fill in the fifth part of cbc:ID directly under Invoice or CreditNote. If you build the number yourself, check the part between the fourth and fifth vertical bars (|); it must not be empty.
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-001-6 still fails, and which other rules do.
Related rules
- GR-R-001-7 Greek invoice number: sixth 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