SIREN vs SIRET: What Every Foreign Business Owner in France Needs to Know

Almost every foreign founder we work with mixes these two up at least once, usually on a form that gets rejected because the wrong number was used in the wrong field. Here is the actual difference, in plain terms.

SIREN identifies the company. SIRET identifies a location.

The SIREN is a 9-digit number that uniquely identifies your legal entity, the company itself, full stop. You will have exactly one SIREN for as long as that company exists.

The SIRET is 14 digits: your SIREN plus a 5-digit suffix (the NIC, numéro interne de classement) that identifies a specific physical establishment. A company with one office has one SIRET. A company that opens a second office, warehouse, or branch gets a second SIRET: same SIREN, different suffix.

In practice: if a form asks for your company's identity (tax filings, most B2B contracts, your K-bis), it usually wants the SIREN. If it asks specifically which location or establishment is invoicing or operating (some VAT and payroll contexts), it wants the SIRET.

You do not apply for either: they are issued automatically

There is no separate application. Both numbers are generated automatically the moment your company registration is processed through the Guichet Unique. You do not need to visit a separate office or file additional paperwork to receive them.

How long it actually takes

Timelines vary by structure: companies (SAS, SARL) typically receive their SIRET within a few days of the commercial court confirming registration, sometimes 48–72 hours if the file was complete and clean. Micro-entrepreneurs usually receive theirs within one to two weeks of declaring their activity. In both cases, you do not have to wait for the physical confirmation letter. Your number is searchable in the SIRENE public database (or via infogreffe.fr) as soon as it is issued.

Every business and self-employed individual in France needs both

This is not optional or structure-dependent. A SIREN and at least one SIRET are mandatory for every registered business and self-employed individual in France, from a solo micro-entrepreneur to a multinational subsidiary.

Where founders get stuck

The confusion rarely causes a real problem on its own. The common failure mode is a founder who invoices, opens a bank account, or files a form using the wrong number, then loses time correcting it. If you are opening your first business bank account or signing your first commercial lease, double-check which number the counterparty is actually asking for before you submit anything. See our guide on registering a company in France for the full sequence this fits into.