| Conitec Datensysteme GmbH | Hesse |
| ConiuGo GmbH | Brandenburg |
| Conlabz GmbH | Rhineland-Palatinate |
| conLeos GmbH | Lower Saxony |
| ConnecT Informationstechnik GmbH | North Rhine-Westphalia |
| Connect Platform UG | |
| connect! Schulungszentrum | Hesse |
| Connect1 | Hesse |
| Connecta AG | Hesse |
| ConnectData GmbH | |
| Connected Reality | |
| Connectish | |
| connectiv! eSolutions GmbH | Lower Saxony |
| ConnectyCube | |
| Connedata Software + Systemnberatung GmbH | Lower Saxony |
| ConPartner - ICT GmbH | |
| Conplus Mittelstandslösungen GbR | North Rhine-Westphalia |
| ConPoint AG | Baden-Württemberg |
| ConPresso | North Rhine-Westphalia |
| Conratio Managementberatung GmbH | Baden-Württemberg |
| Consalco GmbH | Bavaria |
| Consalio | |
| Consedia Consulting | Rhineland-Palatinate |
| ConSense GmbH | North Rhine-Westphalia |
| Consideo GmbH | Schleswig-Holstein |
| Consileon Business Consultancy GmbH | Baden-Württemberg |
| Consipio Software Engineering GmbH | Baden-Württemberg |
| Consistec Engineering & Consulting GmbH | Saarland |
| Consline AG | Bavaria |
| ConSoft GmbH | Lower Saxony |
| ConSol Consulting & Solutions Software GmbH | Bavaria |
| Consolware | |
| Consors Finanz | |
| Constellr GmbH | |
| Constructiva Solutions GmbH | North Rhine-Westphalia |
| Constructor Capital | |
| Constructor University Bremen gGmbH | |
| construktiv GmbH | Bremen |
| Consulaqua Hamburg Beratungsgesellschaft mbH | Hamburg |
| CONSULT Personaldienstleistungen GmbH | |
| Consult+System Group GmbH | North Rhine-Westphalia |
| ConsulTech GmbH | |
| Consulting Union eG | |
| consulting1x1 GmbH | North Rhine-Westphalia |
| Consulting4IT GmbH | |
| CONSYS Gesellschaft für Softwaretechnologie und Systementwicklung mbH | Bavaria |
| CONTA-CLIP Verbindungstechnik GmbH | |
| Contabo GmbH | Bavaria |
| CONTACT Software GmbH | Bremen |
| Contag AG | Berlin |