What it means
When the seller is Italian, the seller's tax number (BT-32), the tax registration number that is not the VAT number, must be 11 to 16 characters long and use only capital letters A to Z and digits. The rule checks each tax registration entry of the seller whose tax scheme is not VAT, so the VAT number itself is not tested. Spaces at the start or end are ignored, but spaces, hyphens or lower case letters inside the number fail.
Why it matters
The Italian rules add this on top of EN 16931, which sets no length for this number. In Italy it is normally the codice fiscale, and Italian systems use it to identify the seller. A number that is too short, too long or has other characters fails the check and the invoice is rejected.
How to fix it
Open your company details in your invoicing software and look at the tax number or codice fiscale field. Remove spaces and hyphens, use capital letters and check that the length is between 11 and 16 characters. In the XML this is cbc:CompanyID in the cac:PartyTaxScheme of cac:AccountingSupplierParty whose cac:TaxScheme/cbc:ID is not VAT. Your VAT number is a separate entry and is not affected by this rule.
The rule as published
Read the rule on the publisher's site
Business terms: BT-32
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 IT-R-001 still fails, and which other rules do.
Related rules
- BR-AE-02 Reverse-charge lines need both VAT numbers
- BR-AE-03 Reverse-charge invoice discounts need both VAT numbers
- BR-AE-04 Reverse-charge invoice charges need both VAT numbers
- BR-AF-02 IGIC lines need a tax number for the seller
- BR-AF-03 IGIC discounts on the whole invoice need a seller tax number
- BR-AF-04 IGIC charges on the whole invoice need a seller tax number