| Copy Service S.R.L. | Bucharest |
| Cos Software Solutions | Bucharest |
| Cosys Computer Systems | Covasna |
| Coworking Bucuresti 160 | |
| Coworkperativa | |
| Craf Interactive S.R.L. | Bucharest |
| Crafting Software | Cluj |
| Creare Site Web | Bucharest |
| CreareWEB.ro | |
| Creative Tim | Bucharest |
| Credia Fintech S.R.L. | |
| Credit Europe Bank | Bucharest |
| Criosweb | Dâmbovița |
| CRIsoft | |
| Crystal Eye | |
| CS-Software S.R.L. | Bucharest |
| CSSTemplatesForFree | Bucharest |
| Cubus Arts | Sibiu |
| Custom Web | Bucharest |
| CustomSoft | |
| CustomSoft | |
| CyberGhost S.A. | Bucharest |
| Cybernet | Bucharest |
| D-Net | |
| DAB MSP | Prahova |
| Dabex Online Market S.R.L. | Bucharest |
| Dallnet | Bucharest |
| Danco Vision S.R.L. | Bucharest |
| Danco Vision S.R.L. | |
| Dante-HD Computers & Trading | Bucharest |
| Data Core Systems | |
| Data Revolt Agency | |
| Datacom International S.A. | |
| DataGrab | |
| Datanest | |
| Datanet Systems | Bucharest |
| DCS Plus | Bucharest |
| Deboot | Timiș |
| DEC-IT | |
| Deck Computers | Bucharest |
| Deep Vision | |
| Defend IT | Alba |
| DeliteSoft S.R.L. | |
| Delphi Webdesign | Bucharest |
| Delta HR Consult | |
| Dendrio | Bucharest |
| Design of Frames | Bucharest |
| Dev-Play | Bucharest |
| Deventure | |
| Devious Technologies | Bucharest |