French SIRET Number Validator
Validate the authenticity, format, and checksum of French SIRET Number.
About French SIRET Number Validation
The SIRET number (Système d'Identification du Répertoire des Établissements) is the 14-digit identifier for each physical branch or establishment of a French company.
Composed of the 9-digit SIREN followed by the 5-digit NIC (Numéro Interne de Classement). All 14 digits must satisfy the Luhn algorithm (Modulo 10).
Anatomy & Structure of French SIRET (14 Digits)
The SIRET number identifies a specific local establishment across 14 digits in 3 blocks:
| Position | Field | Length | Meaning & Rule | Example |
|---|---|---|---|---|
| 1 to 9 | SIREN Number | 9 digits | National company registration identifier | 123456782 |
| 10 to 13 | NIC Code | 4 digits | Facility unit code (typically 0001 for headquarters, 0002+ for branches) | 0001 |
| 14 | Global Check Digit | 1 digit | Luhn checksum validating all 14 digits together | 8 |
SIRET Validation Algorithm (14-Digit Luhn Modulo 10)
Global verification applies the Luhn algorithm across all 14 digits from left to right:
sum(double_at_odd_positions(d_i)) % 10 == 0
- 1. Process left-to-right (1-indexed 1 to 14):
- 2. Odd positions (1st, 3rd, 5th, 7th, 9th, 11th, 13th): double the digit (if > 9, subtract 9).
- 3. Even positions (2nd, 4th, 6th, 8th, 10th, 12th, 14th): keep direct value.
- 4. Sum all resulting components.
- 5. The SIRET is valid if the grand total is evenly divisible by 10 (Sum % 10 == 0).