Italian VAT Number Validator

Italian VAT number (Partita IVA): 11 digits with a Luhn check

Italy's VAT number is the Partita IVA: the prefix IT followed by exactly 11 digits, e.g. IT12345678901. The structure is well-defined: the first 7 digits are a sequential taxpayer number, the next 3 identify the issuing provincial office of the Agenzia delle Entrate (with 100–121, 888 and 999 reserved), and the 11th digit is a check digit.

The check digit uses the Luhn algorithm (mod 10): double the digits in even positions (1-indexed from the left, i.e. positions 2,4,6,8,10), subtract 9 from any result over 9, sum everything; the check digit makes the total a multiple of 10. This is the same family of checksum used by credit cards.

Partita IVA vs Codice Fiscale

• Partita IVA: 11 numeric digits; identifies a business/VAT taxpayer. This is the EU VAT number, validatable in VIES.
• Codice Fiscale: 16 alphanumeric characters for individuals (derived from name + birth date + birthplace), or 11 digits for entities. Companies often have both — for a sole trader the Codice Fiscale and Partita IVA can even coincide as the same 11 digits.
• Codice SDI / PEC: the 7-character recipient code for the mandatory Fattura Elettronica e-invoicing system — separate from the VAT number.

Common pitfalls

• Wrong length: anything other than 11 digits after IT is invalid — no spaces, no letters.
• Invalid office code: the 8th–10th digits must be a valid provincial office (1–100, 120, 121, 888, 999 are the allowed ranges).
• Format ≠ active: a valid checksum doesn't prove the business is open; check VIES or the Agenzia delle Entrate portal for status.

FAQ

How many digits is a Partita IVA? Exactly 11 numeric digits (13 characters with the IT prefix).

What checksum does it use? The Luhn (mod 10) algorithm on all 11 digits.

Can the Partita IVA equal the Codice Fiscale? For a sole trader (ditta individuale), the 11-digit Partita IVA can serve as the entity's Codice Fiscale — but individuals also have their own 16-character alphanumeric code.