| Computers at Work Ltd | Waikato |
| Computers Downunder | Northland |
| ComputerTraining.co.nz | Auckland |
| ComputerWorld New Zealand | Auckland |
| Computerz and More Ltd | Gisborne |
| Computing Solutions Ltd | Canterbury |
| Comrad Medical Systems Ltd | Canterbury |
| Comtek Computing Solutions Ltd | Waikato |
| Comteq Ltd | Canterbury |
| ComX | Auckland |
| Conbrio Technology | Auckland |
| Concilio | Canterbury |
| Conerstone Software Ltd | Auckland |
| ConnectNZ Ltd | Auckland |
| Connexion Point | Auckland |
| Connexionz | Canterbury |
| Consumer Electronics Association of New Zealand | Auckland |
| Contec Group International | Canterbury |
| Contract Eagle Ltd | Auckland |
| Control Power Technology Ltd | Taranaki |
| Convergence | Auckland |
| Copyleft | Otago |
| Core Technology Brokers Ltd | Auckland |
| CoreLogic NZ Ltd | Wellington |
| Corporate Computers | Auckland |
| Corporate Consumables | Auckland |
| Cosine Solutions | Auckland |
| Cosyn Software | Auckland |
| CR8 Software Solutions Ltd | Auckland |
| Craig Thorn PC Repairs Ltd | Wellington |
| Create Hosting Ltd | Waikato |
| Creatit IT | Marlborough |
| Creative Digital Ltd | Auckland |
| Creative Fuel Design | Auckland |
| Creative HQ | Wellington |
| Creative Source Ltd | Auckland |
| Creative Web Ideas Ltd | Northland |
| Credenza Co-working | Wellington |
| Crimson Education | Auckland |
| Cristalink | Auckland |
| Critchlow Ltd | Wellington |
| Crossware Ltd | Auckland |
| Croxford Technology | Otago |
| Cryptlib | Auckland |
| Crystal Electronics Ltd | Auckland |
| CS Unplugged | Canterbury |
| CSE W. Arthur Fisher Ltd | Auckland |
| CT Business Solutions Ltd | Waikato |
| CubeMedia | Waikato |
| Cucumber | Bay of Plenty |