| Clearfield Software Ltd | Auckland |
| ClearPoint Ltd | Auckland |
| Clever Internet | Auckland |
| Click Online | Auckland |
| Click suite | Wellington |
| ClickThrough | Auckland |
| ClikOnce Ltd | Auckland |
| Cloud My Staff | Otago |
| CLOUD39 | Auckland |
| CloudCannon Ltd | Otago |
| CLVR Cloud | Wellington |
| CNC Design Ltd | Auckland |
| Co-operative Bank Ltd | |
| Co-sys group | Auckland |
| Cobussen | Auckland |
| Cobweb Designs | Otago |
| Code Avengers | Auckland |
| Code Camp Wellington | Wellington |
| CodeClouds | Wellington |
| CodeLingo | Otago |
| Cogent Ltd | Auckland |
| Cohesion Online Ltd | Bay of Plenty |
| Com-Centre Communication Equipment Ltd | Auckland |
| Command IT | Auckland |
| Commercial Communications Council | Auckland |
| Communica | Auckland |
| Company-X | Waikato |
| Compass | Wellington |
| Compass Business Partners Ltd | Canterbury |
| Compel Computer Services Ltd | Waikato |
| Compliance Solutions Ltd | Auckland |
| Compu-IT Ltd | Taranaki |
| Compucon New Zealand | Auckland |
| Computablility NZ Ltd | Auckland |
| Computer & Telephone Services Ltd | Wellington |
| Computer Centre (1990) Ltd | Canterbury |
| Computer Craft | Auckland |
| Computer Enhancements NZ Ltd | Auckland |
| Computer Forensics NZ Ltd | Auckland |
| Computer Geek Services | Canterbury |
| Computer Help NZ Ltd | Canterbury |
| Computer Lounge | Auckland |
| Computer Network Support Ltd | Wellington |
| Computer Partners | Wellington |
| Computer Recyclers | Bay of Plenty |
| Computer Shop Timaru 2000 Ltd | Canterbury |
| Computer Technologies Ltd | Nelson |
| Computer Troubleshooters Wellington South | Wellington |
| ComputerFood Ltd | Auckland |
| Computerforce | Auckland |