How to get a SIRET number in France: the complete process

Updated March 2026 - A SIRET number cannot be "ordered" or purchased. It is assigned automatically after completing the official business registration formality for the company or establishment through the guichet unique des formalités d'entreprises (the official one-stop portal for business formalities), and its recording in the official INSEE Sirene directory.

See also check a SIRET number for free, LMNP and SIRET: is it mandatory? and characterising a business correctly.

The SIRET number identifies a specific establishment (not just the legal entity). It is built from two components:

• ▸the SIREN number (9 digits): this identifies the legal entity — the company itself — regardless of how many establishments it has or where they are located;
• ▸the NIC (Numéro Interne de Classement, 5 digits): this identifies a specific establishment of that company — its main office, a branch, a warehouse, a production site.

A business with a single establishment has a single SIRET number. A business with multiple establishments (registered offices, warehouses, retail locations, etc.) has one SIREN and one SIRET for each establishment. The SIRET of the main establishment is typically the SIREN + "00001".

There is no separate process to "get" a SIRET — it is automatically assigned as part of the general business registration process. In practice:

• ▸declare your activity: complete the required registration formality for your legal form (auto-entrepreneur, EURL, SARL, SAS, etc.) through the official guichet unique at formalites.entreprises.gouv.fr;
• ▸complete the online formality: submit the registration request with the required documents — identity, legal form details, registered address, activity description;
• ▸wait for the identifiers to be assigned: the INSEE processes the registration and assigns the SIREN and SIRET numbers. For auto-entrepreneurs and simple registrations, assignment is typically fast — a few days. For more complex structures or certain regulated activities, it may take longer.

Hayot Expertise advice: SIREN/SIRET registration is free through official channels. In 2026, companies — especially newly created ones — must still be alert to letters and payment requests that exploit confusion around the SIRET process. These are commercial solicitations from private registries, not official obligations. The official process goes through formalites.entreprises.gouv.fr and costs nothing for the registration itself.

• ▸LMNP (furnished rental): a specific SIRET question arises for furnished rental landlords — see our dedicated article on LMNP and SIRET obligations;
• ▸opening a new establishment: adding a secondary site or branch to an existing company also requires a formality through the guichet unique, which creates a new SIRET for that establishment;
• ▸change of registered address: moving the company's registered office also requires a formality, which may update the existing SIRET rather than create a new one.

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In 2026, getting a SIRET number means completing the official business registration formality through the correct public channels. The right reflex is always to use the official guichet unique — and to avoid private intermediaries who charge for services that are either free or unnecessary.

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