French Nomenclature des Activités Françaises (NAF) numbers are common codes that are used by the French government to display and track economic statistical data. For instance, if your company manufactures computers, the NAF code for your company might be 300C, which is the NAF code for manufacturing computers and other computer hardware. If your company is involved in building houses, your NAF code would be 452A.
The siret is a 14-digit number that identifies a business, a branch of the business, and a person associated with the business activity. Businesses obtain a siret number at the time of registration with the French government. You can use the siret number to verify that an enterprise is correctly registered and authorized to do business with you.
Since the siret number also is linked to a geographical site, a person or company that does business at more than one location would need a siret number for each location.