Every company registered in France receives a 9-digit SIREN number and at least one 14-digit SIRET number. These two identifiers, assigned by INSEE, refer to distinct realities: the SIREN designates the legal entity, while the SIRET points to a specific place of activity. The Sirene directory is the national database that centralizes all this information.
The NIC code, the technical link between SIREN and SIRET
Most guides detail the SIREN and SIRET separately without explaining the mechanism that connects them. The internal classification number (NIC) is this missing piece. Composed of 5 digits, it is attached to the SIREN to form the SIRET.
The NIC identifies each establishment within the same company. A company operating three points of sale has a single SIREN and three different NICs, thus three distinct SIRETs. When an establishment closes, its NIC is deactivated, but the SIREN remains unchanged.
This modular logic has a practical consequence: a change of registered office generates a new SIRET because the NIC changes, while the SIREN accompanies the company from its creation until its dissolution. To delve deeper into this mechanism, you can access the Gestion Entreprise website which details every scenario.
Sirene Directory: much more than a business directory
The Sirene directory, managed by INSEE, records the civil status of all companies and their establishments located in France, regardless of their legal form or sector of activity. Legal entities, self-employed individuals, local authorities, associations: all are included.
Revisable data, not fixed
INSEE specifies that the data in the Sirene directory can be corrected over time. For a given cohort, the latest delivered file is authoritative. This point is rarely mentioned, but it has a direct impact for companies using Sirene for compliance or internal analysis: an extraction made in January may differ from an extraction covering the same period but conducted in June.
Geocoding and economic mapping
The Sirene datasets are now cross-referenced with other sources, such as the BODACC (Official Bulletin of Civil and Commercial Announcements), to produce maps of the French economic fabric. These uses go beyond simple identification: they allow tracking the creation, transfer, and cessation of establishments on a nearly local scale.
Single window INPI and the process for obtaining SIREN and SIRET
Since 2023, the single window hosted by INPI centralizes the formalities for creating, modifying, and ceasing business activities. This change has concretely altered the process for assigning SIREN and SIRET numbers.
Before this shift, the procedures went through several formalities centers (CFE) depending on the activity. Now, all declarations go through a single entry point, regardless of legal status. INSEE then receives the information transmitted through this window to register the company in the Sirene directory and assign its identifiers.
The direct consequence: any change of address, activity, or manager declared at the single window is reflected in the Sirene directory. A change of registered office address triggers the assignment of a new NIC, thus a new SIRET, without affecting the SIREN.
SIREN, SIRET, and NIC: summary table of differences
| Criterion | SIREN | SIRET | NIC |
|---|---|---|---|
| Number of digits | 9 | 14 | 5 |
| What it identifies | The legal entity (company) | A specific establishment | The establishment within the company |
| Uniqueness | One per company | One per establishment | One per establishment |
| Permanence | Never changes | Changes if the establishment moves or closes | Changes with the establishment |
| Composition | Standalone number | SIREN + NIC | Suffix of the SIRET |
Legal obligations and personal data in the Sirene directory
The Sirene directory contains personal data, particularly for individual entrepreneurs whose names appear in the database. INSEE imposes legal obligations for the use of this data, a point that practical guides rarely mention.
Companies or service providers that exploit Sirene extractions for commercial purposes (prospecting, scoring, file enrichment) must comply with the regulatory framework applicable to personal data. Individuals registered in the directory can request that certain information not be disclosed.
- The SIREN and SIRET appear on invoices, quotes, contracts, and legal notices on a website. Their absence exposes one to sanctions.
- The APE code (main activity exercised), assigned at the same time as the SIREN, determines the applicable collective agreement and serves as a statistical reference.
- Downloadable Sirene extracts in open data do not exempt one from verifying the update date: INSEE corrections may retroactively modify certain information.
The SIREN, SIRET, and Sirene directory form a coherent system where each element plays a specific role. The NIC, often overlooked, is the keystone that articulates the stable identity of the company with the changing reality of its establishments. Regularly checking the consistency of its identifiers at the single window remains the most useful reflex to avoid administrative blockages.