"RCS", a city, then nine digits: French companies print this on their invoices, websites and letters. If you work with French companies, you'll be asked for the number, or you'll need to read one. The good news: there's no separate number to look up. This guide explains what an RCS number is, how it's built, who has one, where to find it, and what it tells you about the company.
Rules come from service-public.fr and Légifrance, read on 10 October 2026.
What you'll learn
- What the RCS is and what an "RCS number" really is
- How it's written, and how to read the SIREN inside it
- Who has one, and who doesn't
- Where companies must show it
- How it fits with the SIREN, the Kbis and the RNE
What the RCS is
The RCS (Registre du commerce et des sociétés) is the French trade and companies register, kept by the registries (greffes) of the commercial courts. According to service-public.fr, registration in the RCS concerns traders (commerçants) and commercial companies.
Since 1 January 2023, a national register run by INPI, the RNE (registre national des entreprises), gathers what three registers used to hold: the national trade register (RNCS), the craft register (RM) and the register of agricultural businesses, according to INPI. Every company with a commercial, craft, agricultural or independent activity in France must be registered in the RNE.
What an "RCS number" is
There's no separate RCS number. According to service-public.fr, the registration number is written:
RCS + city of registration + SIREN
For example: "RCS" then the city whose registry holds the company's file, then the company's nine-digit SIREN.
So when someone asks for your "RCS number", they mean the SIREN with the registry's city. And when you read an RCS number, you can take its last nine digits and look the company up by its SIREN. See how to find a company's SIREN or SIRET.
Who has one, and who doesn't
- Commercial companies (SAS, SASU, SARL, SA…): yes, they're registered in the RCS.
- Individual traders (commerçants): yes.
- Craftspeople and liberal professions: their commercial documents mention "RNE" instead, according to service-public.fr.
- Many micro-entrepreneurs: depending on their activity, they may not be registered in the RCS. They still have a SIREN.
So the absence of an RCS number isn't a red flag in itself: it depends on the activity. The SIREN is the one identifier every business has. See French legal forms explained.
Where companies must show it
Article R123-237 of the Commercial Code requires registered persons to show, on their invoices, order forms, price lists, advertising documents and correspondence: their unique identification number, the mention "RCS" followed by the name of the city of the registry where they're registered, the location of their registered office and, where applicable, the fact that they're in liquidation. Their website must show the same "RCS" mention.
Service-public.fr's page on companies' commercial documents adds, for a company's website and advertising: the SIREN, "RCS" with the city (commercial activity) or "RNE" (craft or liberal activity), the registered office, the share capital for SARL, SAS and SA companies, and the liquidation status if applicable.
In practice, look at:
- the legal notice (mentions légales) of the company's website;
- the footer of its invoices and quotes;
- its terms of sale;
- its letterhead.
What the RCS number tells you
Reading an RCS number gives you two things:
- The SIREN, the company's permanent identity.
- The registry's city: the registry where the company is registered.
What it doesn't tell you:
- Whether the company is still active. A number printed on an old invoice says nothing about today. Check the status: see how to check whether a French company is still active.
- Whether it's in collective proceedings. Look at the BODACC.
- Where it operates. The registered office can be at a domiciliation company.
And if a document mentions "en liquidation" next to the RCS number, the company is in liquidation: that's a mandatory mention under the same article.
RCS, Kbis and RNE: which proof?
- The Kbis extract is the official proof of registration in the RCS, issued by the registry.
- The RNE registration certificate is an alternative proof, available free on INPI's data portal for businesses registered in the RNE, according to service-public.fr.
- The Sirene situation notice from INSEE shows the company's identification and status in the Sirene directory.
Which one to ask for depends on why you need it: see Kbis, Sirene notice and RNE extract.
Common questions from foreign teams
Teams outside France often meet the RCS number for the first time on a supplier form or a French invoice:
- "Our form has a 'company registration number' field." For a French company, put the SIREN there; if the form wants the full reference, write "RCS", the city and the SIREN.
- "The supplier gave us a SIRET instead." The first nine digits of a SIRET are the SIREN. The last five identify a site.
- "The website shows 'RNE' instead of 'RCS'." That's expected for craft and liberal activities, according to service-public.fr. Use the SIREN.
- "Two documents show different cities." A company that moved its registered office can change registry. Look the SIREN up to see the current registered office.
Checking an RCS number
- Take the nine digits after the city.
- Check them with the SIREN's check digit (Luhn): a mistyped number fails it about nine times in ten, according to INSEE's definition. See SIREN, SIRET and VAT formats.
- Look the SIREN up in the State's directory: same name, same registered office, active status.
Fuentio's API will return, for a SIREN, the legal name, legal form, registered office and status with its date, with the source and the check date. It isn't open yet: join the waitlist below to hear the day it opens.
See what we cover in France and Spain.
Limits. Rules come from service-public.fr (identification numbers, page checked on 3 April 2026; commercial documents, page checked on 8 December 2025), Légifrance (article R123-237 of the Commercial Code) and INPI, read on 10 October 2026. Not legal advice.
Frequently asked questions
Is the RCS number different from the SIREN?
No. It's written "RCS", the registry's city, then the SIREN. The nine digits are the same.
Does every French company have an RCS number?
No. Commercial companies and traders do; craftspeople and liberal professions mention "RNE" instead, and some micro-entrepreneurs aren't in the RCS. Every business has a SIREN.
Where can I find a company's RCS number?
In the legal notice of its website, on its invoices, quotes and terms of sale.
What does "en liquidation" next to the RCS number mean?
The company is in liquidation. It's a mandatory mention under article R123-237 of the Commercial Code.
Sources
- Service-public.fr, a company's identification numbers (page checked on 3 April 2026): entreprendre.service-public.gouv.fr
- Service-public.fr, a company's commercial documents (page checked on 8 December 2025): entreprendre.service-public.gouv.fr
- Légifrance, article R123-237 of the Commercial Code: legifrance.gouv.fr
- INPI, the national company register (RNE): inpi.fr
- Service-public.fr, the RNE registration certificate: entreprendre.service-public.gouv.fr
- INSEE, definition of the SIREN number: insee.fr