| C&A | C&M | Cafe |
| Cafe & Bar Celona | Cafeteria | Call Center |
| Call Shop | Camaflex | Camping |
| Campingbedarf | Campingplatz | Campingzubehör |
| CAMPUS72 | Caravan | Carglass |
| Caritas | Caritasverband | caritative Organisationen |
| Carport | Casino | Casio |
| Catering | CBRE | CD-Produzenten |
| CDU | CECIL | Cegelec |
| Chemie | Chemiehandel | Chemikalien |
| chemische Industrie | chemische Reinigung | China Imbiss |
| China Restaurant | Chinese | chinesisches Restaurant |
| Chinesisch Essen | Chiropraktik | Chiropraktiker |
| Chirotherapie | Chirurg | Chirurgie |
| Chor | christliche Vereinigung | Cinegate |
| Cineplex | CineStar | Citizen |
| City PC | CJD | Cleanskin |
| Clinique | Clown | Clubhaus |
| Clubs | CMS Hasche Sigle | CNC |
| Coaching | Cocktailbar | Cocktails |
| Cofely Refrigeration | Coiffeur | Colt Technology Services |
| Comiczeichner | Commerzbank | Computer |
| Computer Großhandel | Computerkurse | Computerladen |
| Computerreparatur | Computertechnik | Computertomographie |
| Computerzubehör Großhandel | Computerzubehör Hersteller | Concordia Versicherung |
| Confiserie | Conrad | Consulting |
| Container | Containerdienst | Containerservice |
| Containertransporte | Copyshop | COP® Polizeiausrüstung |
| COREALCREDIT BANK | Cosmetic | Creditreform |
| CSU | CVJM |
