Check a French VAT number

Paste a French intra-EU VAT number: the tool checks that its two-digit key matches the SIREN that follows, and that the SIREN is itself well-formed. Everything runs in your browser: the number is not sent anywhere.

The calculation runs in your browser: the number you type is not sent to any server.

What this check proves

That a French VAT number is self-consistent: the key is computed from the SIREN — (12 + 3 × (SIREN mod 97)) mod 97 — and the SIREN carries its own Luhn digit. A number copied with a typo, or invented to dress up a fake invoice, almost always fails.

On an invoice the VAT number must match the SIRET printed next to it: the first nine digits of the SIRET are the SIREN that follows the key. A gap between the two is one of the most telling inconsistencies, and one TrustyFile looks for in a document.

What it does not prove

That the number is assigned, active and registered for intra-EU trade. Only the European Commission's VIES database answers that, by querying the country's tax administration. A French business under the VAT exemption threshold may have no intra-EU number at all and still be perfectly real.

Some French numbers have a key containing letters, computed with a different algorithm: this tool reports them as out of scope rather than validating or rejecting them wrongly.

How to read the result

• Key valid: the number is consistent. Compare it with the SIRET on the invoice and, for a new supplier, look it up in VIES.
• Key invalid, SIREN well-formed: the expected key is shown. A single typo explains it — so does a fabricated number.
• SIREN invalid: the core of the number is wrong; copy it again from the original document before concluding.

Check the whole invoice, not just the VAT number

TrustyFile runs this check on the numbers found in a PDF, matches the VAT number against the SIRET, queries the company register, then looks for what a consistent number will never reveal: a covered amount, a revision added afterwards, hidden text.

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