| Comet Kft. | |
| ComParts Line Kft. | Budapest |
| Compete Digital | Budapest |
| Compocity Kft. | |
| Component Soft | |
| Component Soft Kft. | Budapest |
| Compure Kft. | Budapest |
| Computer Emporium | |
| Computer Imperium Kft. | Budapest |
| Computerworld.hu | Budapest |
| CompuTREND Zrt. | |
| Compuworx Informatikai Zrt. | Budapest |
| Comsys Software | |
| Comtech Kft. | |
| Conet Számítógép és Hálózatfejlesztő Kft. | Budapest |
| ConfigCat | |
| ConorFund | |
| Consulting Hungary | |
| Control X-Medical Ltd | |
| CONTROLLTraining Kft. | Budapest |
| Cordines Computer Kft. | Budapest |
| Coretechs Solutions | |
| Cosmo Consult Kft. | Budapest |
| CoWo Budapest | |
| Craftbot | |
| cre-art stúdió | Zala |
| Creatic Online Kft. | |
| Creatit Solutions Kft. | |
| Creative Accelerator | |
| Crome Communication Kft. | |
| CrySyS Lab | |
| CSB IT Hosting & Consulting Bt. | |
| Cubicfox Kft. | |
| Cubilog Digital | |
| Cubilog Kft. | |
| CyberBanan.hu | Szabolcs-Szatmár-Bereg |
| CycloLab | |
| Cytocast | |
| D-Link Magyarország Kft. | Budapest |
| D2 Digital Studio | |
| DAM Invisible Technology | |
| Danubus IT Solutions | |
| Dasetech Kft. | |
| Data-Press Informatikai Kft. | |
| Data36 | |
| DataConsult Kft. | Hajdú-Bihar |
| DataExpert Services Ltd | |
| Dataking Kft. | |
| Datamagic | |
| Datapao | |