Before choosing a name, check that it does not copy or imitate a name already protected for identical or similar activities: registered companies (search on DATA INPI), filed trademarks, and trade names or shop signs already in use. If an earlier right exists, its holder can sue for infringement or unfair competition and force you to change your name, even after registration. 
INPI
What to check
| Database | What it protects | Where to search |
|---|---|---|
| National business register (RNE) | Company names, protected throughout France from registration | DATA INPI |
| Trademarks | The name for the goods and services it covers | INPI trademark databases |
| Trade names and shop signs | The name used with the public, protected in the area where the business has its customers | DATA INPI, web search |
| Domain names | Your online address | Domain name registries |
Company name, trade name, shop sign: three different things
- The company name (dénomination sociale) is the company's official name, the one in the articles of association and on the Kbis.
- The trade name is the name the public knows you by; it can differ from the company name.
- The shop sign (enseigne) identifies a place of business, for example on a shopfront.
An identical name is not always forbidden
The risk arises when the name is identical or similar and the activities are identical or similar. A name already used by a company in a completely different sector may still be usable; when in doubt, a prior-rights search by an industrial property attorney settles it.
Protecting the name afterwards
If the name is also the name of your products or services, the INPI recommends filing a trademark: the company name alone does not protect the name of your products. 
Service-public
Written by Razvan Toma, founder of LegalRapide. How we check our figures · LinkedIn