| Croxford Technology | Otago |
| CruzPro Ltd | |
| Cryptlib | Auckland |
| Crystal Electronics Ltd | Auckland |
| CS Unplugged | Canterbury |
| CSE W. Arthur Fisher Ltd | Auckland |
| CSL Design | |
| CSL Invercargill | |
| CT Business Solutions Ltd | Waikato |
| CubeMedia | Waikato |
| Cucumber | Bay of Plenty |
| Cuik Technologies Ltd | |
| Curative | Auckland |
| Cure Kids Ventures Ltd | Auckland |
| Curonz Ltd | |
| Custom Digital Marketing | |
| Custom website designers | Auckland |
| Custom365 | |
| Custombased Software | |
| CustomD | Canterbury |
| Cyber Spot | Auckland |
| CyberCom | Auckland |
| CyberKode | Auckland |
| CyberWorkshop | |
| Cyclone Computer Co Ltd | Auckland |
| Daisy Lab | |
| Dalyn Software Ltd | Wellington |
| Dash Design | Auckland |
| Data Cal | |
| Data Management Solutions Ltd | Wellington |
| Data Recovery Services Ltd | Canterbury |
| Data Synthesis Ltd | Auckland |
| Data.gov.nz | Auckland |
| Data4U Ltd | Auckland |
| Databases By Design Ltd | Wellington |
| Datacable | Auckland |
| Datacom Group Ltd | Auckland |
| Datacomms Plus Ltd | |
| Datadog | Bay of Plenty |
| DataGenius Software Labs Ltd | |
| Datagroup Solutions | Auckland |
| DataguardNZ Ltd | Auckland |
| Dataimporter | Auckland |
| Datalab Ltd | Auckland |
| Datanow | |
| DataTalk | |
| DataTorque | Wellington |
| Davanti Consulting Ltd | Auckland |
| DBS Business Systems Ltd | Auckland |
| DCL Computer Services | Wellington |