What it means
When the seller is Italian, the seller's postal address must contain the post code (BT-38), known in Italy as the CAP. EN 16931 makes it optional; the Italian rules do not.
Why it matters
The Italian rules require the seller's postal address on the invoice. Without the post code the invoice fails the check and is rejected.
How to fix it
Open your company details in your invoicing software, go to the address and fill in the post code. In the XML this is cbc:PostalZone in cac:PostalAddress of cac:AccountingSupplierParty.
The rule as published
Read the rule on the publisher's site
Business terms: BT-38
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-004 still fails, and which other rules do.
Related rules
- BR-DE-4 Seller postcode is required
- BR-RO-L0201 Seller post code must be 20 characters or fewer
- DE-R-004 The seller post code is required between German parties
- IS-R-003 Icelandic sellers must give a street name and post code
- IT-R-003 Italian sellers must give the city in their address
- IT-R-002 Italian sellers must give the street in their address