| Code Runners | Sofia |
| Codecover | Sofia |
| Coherent Labs | Sofia |
| Coinpanda | Sofia |
| CoinPoint | Sofia |
| Colibra | Sofia |
| Colibri ERP | Sofia |
| Comac Medical Ltd | Sofia |
| Comel Soft Multimedia Ltd | Sofia |
| Commission for Personal Data Protection | Sofia |
| ComNet | Sofia |
| Computer 2000 | Sofia |
| Computer Security Services | Sofia |
| Computerworld.bg | Sofia |
| ComSoft Ltd | Sofia |
| Concept Digital | Sofia |
| Coolbox | Sofia |
| Corpus | Sofia |
| Coshare HIVE | Sofia |
| Creative Brains | Sofia |
| Creative Corner Studio | |
| Creative Point | Sofia |
| Creative Web Bulgaria | Sofia |
| Creativeideas | Sofia |
| Creativity Design Studio | Sofia |
| Cryptoken Media | Sofia |
| CSoft | Varna |
| D&G Technology | Sofia |
| DAIS | Sofia |
| Daisy Technology | Sofia |
| Daskal.eu | Sofia |
| Data Science Society | Sofia |
| Data Solutions | Sofia |
| DataArt | Sofia |
| Datacenter Bulgaria | Sofia |
| DataMax | Sofia |
| Datamax Ltd | Sofia |
| Datecs Ltd | Sofia |
| Daticum | Sofia |
| DAVID Holding Company | Sofia |
| Dekada Digital | Sofia |
| Dekom | Sofia |
| Delinx.Digital | Sofia |
| DelivMe | Sofia |
| Delta.BG | Sofia |
| Denkovi Assembly Electronics Ltd | Varna |
| Desc Satellite | Sofia |
| Descom | Sofia |
| Design Studio 42 | Sofia |
| DEV.BG | Sofia |