Article R123-237 of the French Commercial code
All registered persons shall indicate on their invoices, order forms, price lists and advertising documents as well as on all correspondence and receipts concerning their activity and signed by them or on their behalf: 1° The unique company identification number issued in accordance with Article D. 123-235 ; 2° The mention RCS followed by the name of the town where the registry office where it is registered is located; 3°…