Free tool
SIREN Number Lookup
Type a SIREN and the check reports whether it is nine digits with a valid Luhn check digit. It reads the number, not the register. INSEE, which issues SIREN numbers, is where the company is confirmed.
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The result appears here. Nothing is stored, and the allowance is per visitor per day.
Example result
A well-formed SIREN
- SIREN
- 303265045
- Digits
- 9
- Luhn check digit
- Matches
- Verdict
- Well formed
- Where to confirm
- INSEE Sirene
SA SODIMAS carries this SIREN in the French register. Passing here says the digits are well formed; INSEE is where the company behind the SIREN is confirmed.
A real check above replaces this example.
What the check reads
- Nine digits
- The count runs after spaces and dots are stripped. A SIRET adds five digits for one establishment, so a fourteen-digit number fails here as a SIREN.
- The Luhn check digit
- The last digit is computed by the Luhn rule over the first eight. If the recomputed digit does not match, the number is not well formed, which usually means a transposed pair.
- Spaces and dots
- The number is often written in groups, as in 303 265 045. Separators are formatting only, so the check ignores them.
- SIREN and SIRET
- The SIREN is the nine-digit entity number. The SIRET is the SIREN plus five digits for one premises. A SIRET passes only its first nine digits, which are the SIREN.
- What this does not check
- Whether the number was issued, which company holds it, and whether it is still active. INSEE holds all of that in the SIRENE register.
Where the answer comes from
- INSEE
The French statistics institute that holds the SIRENE register and issues SIREN numbers.
- Annuaire des entreprises
The public company directory built on the SIRENE register, for confirming a SIREN or SIRET.
Worked examples
Example inputs and the results they return.
A well-formed SIREN
- SIREN
- 303265045
- Digits
- 9
- Luhn check digit
- Matches
- Verdict
- Well formed
- Where to confirm
- INSEE Sirene
SA SODIMAS carries this SIREN in the French register. Passing here says the digits are well formed; INSEE is where the company behind the SIREN is confirmed.
Two digits transposed
- Digits
- 9
- Luhn check digit
- Does not match
- Verdict
- Not well formed
- Likely cause
- Two digits transposed or one mistyped
Swapping the last two digits breaks the Luhn sum, so the number cannot be a real SIREN.
One digit short
- Digits
- 8
- Needed
- 9
- Verdict
- Not a SIREN
A SIREN is nine digits, so an eight-digit input is short by one. A fourteen-digit SIRET fails here too and should be trimmed to its first nine digits.
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