Each SIREN unit identifies a legal unit. A legal unit is an individual company or a company exercising a productive activity. The directory SIREN is exhaustive on the field of the trade productive units. It integrates non-market units (municipality, a professional syndicate, an association, a joint-ownership administrator or a State department).
In theory, the SIREN is an individual or legal entity conducting a non-salaried activity on its own account. It is identified by the SIREN number.