Italian VAT Number Validation
Format, pattern, and Luhn checksum algorithm for IT VAT numbers
Italian VAT numbers (Partita IVA or P.IVA) consist of 11 digits and use the standard Luhn algorithm for validation.
Format vs. Active Validation
This checks format only, not if a VAT number is really registered. Use VatDB's API to verify if a number is really registered and active. VatDB checks official EU and national datasources.
Format Overview
| Property | Value |
|---|---|
| Country Code | IT |
| Format | 11 digits |
| Length | 11 digits (13 characters with IT country prefix) |
| Examples | IT10115350158 IT01654010345 IT00159560366 |
Number Structure
- Digits 1-7: Company identifier
- Digits 8-10: Province code
- Digit 11: Check digit (Luhn)
Regex Pattern
^IT[0-9]{11}$
Checksum Algorithm (Luhn)
def validate_it_vat(number):
if number.startswith('IT'):
number = number[2:]
if len(number) != 11 or not number.isdigit():
return False
# Luhn algorithm
total = 0
for i, digit in enumerate(reversed(number)):
d = int(digit)
if i % 2 == 1: # Double every second digit from right
d = d * 2
if d > 9:
d -= 9
total += d
return total % 10 == 0
Important Notes
- Domestic Italian Partita IVA values are 11 digits. The EU/VIES format adds the
ITcountry prefix, for exampleIT12345678901. - An Italian VAT number can be valid domestically in Italy, but invalid for use in intra-EU commerce. Use VatDB to verify if an IT VAT number is eligible for intra-EU use.
- Preserve leading zeros when storing, normalizing, or validating Italian VAT numbers. Treat them as strings, not integers.
Frequently Asked Questions
How do I verify an Italian VAT number (Partita IVA)?
Italian VAT numbers use the Luhn algorithm for validation. Check that it has 11 digits, then apply Luhn checksum. Use VatDB's API for official verification against EU and Italian Agenzia delle Entrate databases.
What does an Italian VAT number look like?
An Italian VAT number (Partita IVA) has the format IT12345678901 - IT followed by exactly 11 digits. The first 7 digits identify the company, digits 8-10 are the province code, and digit 11 is the check digit.
How many digits are in an Italian VAT number?
An Italian VAT number (Partita IVA) contains exactly 11 digits after the IT country code. The complete number is 13 characters: IT + 11 digits.
What is a Partita IVA in Italy?
Partita IVA (P.IVA) is the Italian VAT number. 'Partita' means account/registration and 'IVA' stands for Imposta sul Valore Aggiunto (Value Added Tax). All Italian businesses need one for VAT purposes.
What do the digits in an Italian VAT number mean?
In an Italian Partita IVA: digits 1-7 are the company identifier, digits 8-10 indicate the province of registration, and digit 11 is the Luhn check digit.
How can I check an Italian company's VAT registration?
VatDB's API validates Italian VAT numbers against official EU and national databases in real-time. Get instant verification with company details and registration status.
What's the difference between format validation and checking if a VAT number is active?
Format validation ensures the number is correctly structured but says nothing about actual registration. A business might have closed or the number could be fabricated. VatDB verifies real status.
What are valid, real-world Italian VAT numbers?
Some active Italian VAT numbers from real businesses: IT10115350158, IT01654010345, IT00159560366.