| CPK Automotive GmbH & Co. KG | North Rhine-Westphalia |
| cplus Informationssysteme und -beratung GmbH | Schleswig-Holstein |
| CPN Cooperation Network GmbH | |
| CPN Satellite Services GmbH | Hesse |
| CPS Administration GmbH | Rhineland-Palatinate |
| CPS Systemhaus GmbH | Baden-Württemberg |
| CPS-Datensysteme GmbH | Rhineland-Palatinate |
| CPS-IT GmbH | Berlin |
| CPU IT-Dienstleistungen GmbH | Saarland |
| CPU Software & Service GmbH | Saxony |
| CPU Softwarehouse AG | Bavaria |
| CPU-net e.K. | |
| Craftview Software GmbH | |
| Cramer & Consorten GmbH | Hamburg |
| Crash-PC-Service GmbH | Berlin |
| Crazy Compilers | Bavaria |
| CreAktiv komma münchen GmbH | |
| CreaLog GmbH | Bavaria |
| Crealytics GmbH | |
| Creanetsoft | Thuringia |
| CREATEOCEANS GmbH & Co. KG | North Rhine-Westphalia |
| CREATHOR VENTURE Management GmbH | Hesse |
| Creative Media Service GmbH | Bavaria |
| Creative Promotion | Baden-Württemberg |
| Creative Soft-& Hardware | Hesse |
| Creative-Networks Application Development UG (haftungsbeschränkt) | Bavaria |
| creative-webdesign | Hesse |
| Creative360 | Baden-Württemberg |
| CreativeDogDesign | Saxony |
| CreativeNet | Lower Saxony |
| Creators by Drees & Sommer SE | |
| Credativ GmbH | North Rhine-Westphalia |
| credia communications GmbH | North Rhine-Westphalia |
| Credit Europe Bank N.V., Niederlassung Deutschland | |
| CreditLinks GmbH | |
| Creditplus Bank AG | Baden-Württemberg |
| credX AG | |
| CRELUX GmbH | |
| Creopard Network & Websolutions | Bavaria |
| Creos Lernideen und Beratung GmbH | North Rhine-Westphalia |
| Criadero GbR | Brandenburg |
| Crispy IT-Solutions GmbH & Co. KG | |
| crisscrossed GmbH | Hesse |
| CRM InformationSystems GmbH | Bavaria |
| crm-now GmbH | Berlin |
| Cronon GmbH | Berlin |
| Cronsync | Berlin |
| CROSS Solution | |
| crossbase mediasolution GmbH | Baden-Württemberg |
| Crossconcept GmbH | North Rhine-Westphalia |