| Claimsforce GmbH | Hamburg |
| Claneo | |
| Clanq AG | |
| Claranet GmbH | Hesse |
| CLARIN-D | |
| Clarity & Success Software GmbH | North Rhine-Westphalia |
| Clarity AG | Hesse |
| Clark Germany GmbH | Hesse |
| Claro AI | |
| Clasen Datensysteme GmbH | Rhineland-Palatinate |
| Classix Software GmbH | Hamburg |
| ClassWizard GmbH | Hamburg |
| Claudia und Andreas Unkelbach | Hesse |
| Claw Design Software | Baden-Württemberg |
| CLC Unternehmensberatung für Logistik GmbH | Baden-Württemberg |
| Clean Code Developer | |
| CleanHub | |
| Clearingstelle | Baden-Württemberg |
| Clearline Design | Schleswig-Holstein |
| Clemens GmbH | Bavaria |
| Clever + Zöger GmbH | North Rhine-Westphalia |
| Clever Elements GmbH | Berlin |
| Cleverbridge | North Rhine-Westphalia |
| Cleverbridge AG | North Rhine-Westphalia |
| Cleverciti Systems GmbH | |
| CleverReach GmbH & Co. KG | |
| Cleversoft GmbH | Bavaria |
| Cleverworks | Hesse |
| Clevver GmbH | |
| CLiB Computerlösungen im Bauwesen GmbH | Hamburg |
| Click Effect | Baden-Württemberg |
| Click Solutions GmbH | |
| Clickconcepts GmbH | Baden-Württemberg |
| Clickfineon | Rhineland-Palatinate |
| Clicks Digital GmbH | |
| CLICKSPORTS GmbH | Bavaria |
| clickstorm GmbH | |
| clickworker GmbH | North Rhine-Westphalia |
| Climate Founders GmbH | |
| Climatiq Technologies GmbH | |
| Climedo Health GmbH | |
| ClinFlows UG (haftungsbeschränkt) & Co. KG | |
| Clink | |
| ClipboardAI | |
| Cliptec GmbH | Lower Saxony |
| clockin GmbH | |
| Clockodo | North Rhine-Westphalia |
| close2 new media GmbH | |
| closetag UG (haftungsbeschränkt) | |
| Cloud Monsters GmbH | |