Check a French VAT number

A French VAT number is checked in two steps: its check key, which you can compute from the SIREN, then its active registration in the EU's VIES database. The tool below does the first step instantly.

Updated October 14, 2026

Only have the SIREN? Enter it in the SIREN / SIRET tool: it works out the matching VAT number.

How a French VAT number is built

It has 13 characters: FR, a 2-digit key, then the company's 9-digit SIREN. For example: FR 44 732829320.

The key is computed as:

key = (12 + 3 × (SIREN mod 97)) mod 97

A number whose key doesn't match its SIREN is necessarily wrong: a typo, or a made-up number. A few old numbers use an alphanumeric key; those can only be checked on VIES.

Is it active? VIES

A valid key proves the number is well formed, not that it's assigned or active. For that, use VIES, the European Commission's free service: it tells whether the number is valid today and, for France, the company name.

Why check it

• On an invoice you receive: the supplier's VAT number must match its SIREN. A mismatch is a warning sign.
• For an intra-EU sale: the VAT exemption requires a valid customer VAT number, printed on the invoice.
• Under reverse charge: the customer's number is a mandatory mention.

Other EU countries

Each country has its own format: DE and 9 digits for Germany, BE and 10 digits for Belgium, IT and 11 digits for Italy, and so on. Check keys differ by country; VIES checks them all.