What it means
When the seller is Greek, the third part of the invoice number (BT-1) cannot be empty and has to be a whole number, 0 or higher. The official text says positive integer, but the test accepts 0 as well. An empty part, a negative number and text all fail. It applies to invoices and credit notes.
Why it matters
Peppol BIS Billing 3.0 requires the third part of a Greek seller's invoice or credit note number to contain a whole number of 0 or higher.
How to fix it
Correct the third part of cbc:ID directly under Invoice or CreditNote. Enter a whole number of 0 or higher, with no decimal part or text, and do not leave the part 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-001-4 still fails, and which other rules do.
Related rules
- 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
- 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