Check the Luhn key of a French establishment number

Administrative teams check a SIRET before adding a supplier, customer or establishment to records and business workflows.

Check the Luhn key of a French establishment number. No registration is needed to obtain a clear output that is ready for real work.

How to use

Paste a fourteen-digit SIRET into the field after removing spaces, dots and other separators from the number.
Run the verification action to apply the Luhn key check to the digits you supplied.
Look at the returned message to learn whether the SIRET is consistent or flagged as invalid.
When the result is negative, compare the number with your source record and correct any typing error.
Use the erase control afterwards if the screen may be seen by other people.

Example

An administrative assistant adding a new supplier location pastes the SIRET 12345678200002. They confirm that the Luhn key is accepted before saving the record, then check the name and address in their own business system.

Input

12345678200002

Limits and formats

The check validates the format and key, not whether the establishment truly exists.
A valid SIRET can still belong to a closed location or a different activity.
Input must contain fourteen digits, with no letters or punctuation.
It does not replace an official registry lookup for address or legal status.
A successful check should still be reviewed by a person before accounting use.

Where processing happens

The verification takes place entirely in your browser. The fourteen digits stay on your device and are not sent anywhere while the key is being checked.

Frequently asked questions

Does a SIRET always have fourteen digits?

The format used here expects fourteen digits: the nine-digit SIREN plus a five-digit establishment number. Remove any spaces, dots or hyphens before running the check.

Why is a correct SIRET rejected?

A typing error, a reversed digit or a forgotten separator can break the Luhn key. Check the original source, then paste only the fourteen digits and run the verification again.

Does the tool show the establishment name?

No. It only checks the Luhn key of the number. To find the legal name, address or activity, use an official registry, your accounting software or another trusted record.