What it means
When the seller is Greek, the invoice number (BT-1) must be built from exactly six parts separated by the vertical bar character (|). This rule only counts the parts. GR-R-001-2 to GR-R-001-7 check what each part contains. It applies to invoices and credit notes.
Why it matters
Peppol BIS Billing 3.0 requires a six-part number for invoices and credit notes from Greek sellers.
How to fix it
Check how your invoicing software builds the invoice number. If you type the number yourself, make sure it has exactly five bars and that no part contains a bar of its own. In the UBL file it is the cbc:ID directly under the Invoice or CreditNote element.
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-001-1 still fails, and which other rules do.
Related rules
- GR-R-001-2 Greek invoice number: first part must be a valid TIN
- GR-R-001-3 Greek invoice number: second part must be the invoice date
- GR-R-001-4 Greek invoice number: third part must be a whole number
- GR-R-001-5 Greek invoice number: fourth part must be a document type
- GR-R-001-6 Greek invoice number: fifth part must not be empty
- GR-R-001-7 Greek invoice number: sixth part must not be empty