What is the Partita IVA?
The Partita IVA (literally "VAT share") is Italy's VAT identification number. It is an 11-digit numeric code assigned by the Agenzia delle Entrate (Italian Revenue Agency) to any entity — companies, sole traders, freelancers, and professionals — that carries out VAT-relevant economic activity in Italy. When prefixed with the country code IT, it forms the 13-character EU VAT number (e.g. IT12345678901).
Every business that issues invoices in Italy must have a Partita IVA, and every B2B invoice routed through the Sistema di Interscambio (SDI) must carry the sender's and receiver's Partita IVA in the correct XML fields.
Structure of the 11 digits
The 11 digits are not random — they encode routing information:
Ufficio) that issued the VAT number.Importers of Italian invoice data should reject any value that is not exactly 11 digits, has a failed check digit, or uses an out-of-range office code.
Partita IVA vs. Codice Fiscale
A common source of confusion for ERP vendors entering the Italian market: the Codice Fiscale is a different identifier.
On FatturaPA invoices, both may appear on the same party: the Partita IVA in cac:PartyTaxScheme/cbc:CompanyID, and the Codice Fiscale in cac:PartyLegalEntity/cbc:CompanyID (typically with @schemeID set to 0210 for the Italian fiscal code scheme).
Where the Partita IVA Appears in E-Invoicing
On an EN 16931-compliant invoice, the Partita IVA is used as the VAT identifier for both seller and buyer:
IT + 11 digits.In Peppol and FatturaPA, the Partita IVA is also used for routing via the Endpoint ID under scheme 0201 for public administrations (IPA index) or as part of the SDI's own routing resolution through the Codice Destinatario (SDI code).
UBL and CII Representation
In UBL, the Italian VAT number populates cac:PartyTaxScheme/cbc:CompanyID with cbc:TaxScheme/cbc:ID set to VAT. In CII/FatturaPA, it lives under ram:SpecifiedTaxRegistration/ram:ID with @schemeID="VA".
What ERP Developers Need to Know
If you're building invoicing or accounting software that serves Italian customers:
1. Validate on input — Enforce the 11-digit format and verify the check digit at data-entry time. Invalid Partita IVAs are a leading cause of SDI rejection codes.
2. Don't confuse with Codice Fiscale — Separate fields, separate validation rules. Some entities have one, some have both.
3. Normalise the country prefix — Internally store the raw 11 digits plus the country code; EN 16931 and Peppol expect the full IT + 11-digit form.
4. Check VIES for EU cross-border transactions — For intra-community supplies, the Partita IVA must be valid in the EU VIES database on the date of the transaction.
5. Handle closed VAT numbers — Partita IVAs can be deactivated (cessata). Your master-data logic should distinguish active from closed numbers before allowing an invoice to be issued.
Relation to EN 16931 and the SDI
The Italian FatturaPA format is a CIUS (Core Invoice Usage Specification) built on top of EN 16931's semantic model, but it uses a national XML schema rather than pure UBL or CII. The Partita IVA is one of the few fields that has identical meaning across all three — EN 16931's BT-31/BT-48, Peppol BIS 3.0, and FatturaPA — which makes it one of the most portable pieces of data in cross-format conversions.