| Bürger-Energie Lichtenau eG | — | — | Lichtenau | Germany |
| Bürger-Energie Region Mühlacker eG | — | — | Mühlacker | Germany |
| BürgerEnergieGenossenschaft Nordeifel eG | — | — | Roetgen | Germany |
| Bürgerenergie Bille eG | — | — | Wohltorf | Germany |
| Bürgerwerke | — | — | Heidelberg | |
| Bürgerwindpark Vinstedt GmbH & Co. KG in Gründung | — | — | Natendorf | Germany |
| Bürklin GmbH & Co. KG | info@buerklin.com | — | Oberhaching | Germany |
| C+J Immobilien GMBH & Co. KG | — | — | Essingen | Germany |
| C-Werk GmbH | — | — | Aachen | Germany |
| C.Ed. Schulte GmbH Zylinderschlossfabrik | — | — | Velbert | Germany |
| CALOR | — | +49 2401 91790 | Baesweiler | Germany |
| CAMPELL GROUP | — | — | — | Switzerland |
| CBRE Group, Inc. | — | +1 214-979-6100 | Dallas | United States |
| CCD Weber | — | — | — | |
| CCG automotive | — | +49 241 60844320 | Aachen | Germany |
| CENA Kunststoff | — | — | Vienna | United States |
| CERTUSS Dampfautomaten GmbH & Co. KG | — | — | Krefeld | Germany |
| CEVA Logistics | — | — | Marseille | France |
| CH AG | — | — | Kaltbrunn | Switzerland |
| CHIO Aachen | — | — | Aachen | Germany |
| CMC Klebetechnik GmbH | info@cmc.de | +49 6233 872300 | Frankenthal (Pfalz) | Germany |
| CO-POWER GmbH | — | — | München | Germany |
| COBUS ConCept GmbH | — | — | Rheda-Wiedenbrück | Germany |
| CT Engineering | — | — | Milton | United Kingdom |
| CUBOS Service GmbH | — | +4953616549500 | Wolfsburg | Germany |