What is the SIREN number?
SIREN stands for Système d'identification du répertoire des entreprises. The number identifies the company itself, that is, the legal unit: a company, a sole trader, an association or a public body. It does not change when the company moves, changes its name or its legal form. It disappears only with the company.
The company has nothing to do to obtain it: it receives it automatically once its registration is accepted, together with the SIRET of its first establishment. The Service-Public page “How to obtain a Siren or Siret number?” (in French) explains these rules.
The format: 9 digits and a check digit
A SIREN has exactly 9 digits. It is often written in groups of three, for example 552 100 554, but the spaces are not part of the number. The last digit is a check digit that catches typing mistakes: a missing or swapped digit almost always produces an invalid number.
A correct check digit does not mean the company exists or is active. For that you have to look the company up. The SIREN is also the basis of two other numbers:
- the SIRET, 14 digits, identifies each establishment: the SIREN followed by 5 digits (the NIC). See SIREN vs SIRET vs NIC: what is the difference?;
- the French intra-community VAT number, FR followed by two key characters and then the SIREN. See French VAT number: format and how to check it.
Who has a SIREN number?
- Companies: SAS, SARL, SA, civil companies and so on;
- sole traders, including micro-entrepreneurs, craftspeople, shopkeepers and the liberal professions;
- associations that employ staff, pay taxes or apply for public grants;
- government bodies, local authorities and public institutions.
A private individual has no SIREN, and neither does a foreign company with no declared activity in France. Each country has its own number: the 10-digit enterprise number in Belgium, the UID (CHE-…) in Switzerland, the company number in the United Kingdom.
Where to find a company's SIREN
The number appears on most of the company's official and commercial documents:
- The Kbis extract of a commercial company, where it appears as the identification number, often as “RCS” followed by the city of the registry court and the SIREN;
- its invoices and quotes, where the seller's SIREN is a mandatory mention; since 1 September 2026 the customer's is too (see France e-invoicing 2026);
- the legal notice of its website, which states the company's registration number;
- its VAT number, whose last 9 digits are the SIREN for a French company;
- a SIRET of one of its establishments, whose first 9 digits are the SIREN.
The most reliable way is to ask the company itself for the number, then verify it: a number copied from an old document can belong to a closed company or to another company of the group.
Finding the SIREN from the name
When you only know the name, the difficulty is companies with the same name: a common brand can match dozens of companies, franchisees, subsidiaries or co-ownership associations. Three details help you pick the right one:
- the city or postcode of the head office;
- the status: rule out closed companies first;
- the legal form and the activity, to tell an operating company from a holding company or a sole trader.
If in doubt, ask the customer to confirm: a wrong SIREN on an invoice is better corrected before sending than after a rejection.
With Companies: the SIREN in one call
Autocomplete suggests companies from the first letters, with their postcode and city. Exact names and active companies come first:
curl "https://companies.jsonpage.com/v2/autocomplete?q=carrefour&country=FR&limit=5" \
-H "X-API-Key: $COMPANIES_API_KEY"Each suggestion contains a global identifier, for example FR-652014051: the country code followed by the SIREN. You then just read the company record, for example GET /v2/companies/FR-552100554, to get its name (PEUGEOT SA), its status (here closed: the company is closed), its legal form, its activity and its dates. A number typed into the search, SIREN or SIRET, returns its company directly.
For fuller results (legal form, activity, creation date), the name search returns whole records. Without writing code, the Tester in your account area sends the same requests from your browser, and enrichment completes an entire file.
Frequently asked questions
How many digits does a SIREN number have?+
Nine. It is often written in groups of three (552 100 554), but the spaces are not part of the number. A 14-digit number is a SIRET, which identifies an establishment.
Does the SIREN change when the company moves?+
No. The SIREN stays the same for the whole life of the company, even if it changes address, name or legal form. It is the SIRET that changes when an establishment changes address.
Does a micro-entrepreneur have a SIREN?+
Yes. Every sole trader, micro-entrepreneurs included, receives a SIREN when registered, and a SIRET for the establishment.
How do I check that a SIREN is valid?+
The check digit catches a typing mistake, but only looking up the company confirms that it exists and is active. With Companies, GET /v2/validate does both in one call.
Keep reading
- E-INVOICINGFrance e-invoicing 2026: why your customers' SIREN becomes mandatoryThe four new mandatory mentions, the 2026-2027 timeline and how to verify your customers' SIREN numbers.
- SIREN · SIRETSIREN vs SIRET vs NIC: what is the difference?The company and its establishments: 9 or 14 digits, the role of the NIC and the right number for each use.
- VATFrench VAT number: format and how to check itThe French, Belgian and Swiss formats, the mentions on the invoice and the check before invoicing.