| ID | Name | Type |
|---|---|---|
| #2774 | Consult Software Ltd | P |
| #2775 | Consumer Electronics Ltd | Z |
| #2776 | Consumers' Association | Z |
| #2777 | Continental Movie Productions | Z |
| #2778 | Continental Software | Z |
| #2779 | Contrast Software | Z |
| #2780 | Control Software | Z |
| #17969 | Control Technology | Z |
| #2781 | Convention | Z |
| #2782 | Conver-Utility | ? |
| #2784 | Coo Coo Soft | Z |
| #2785 | Cookridge Computer Supplies | Z |
| #2786 | Coolguys Ltd | Z |
| #2787 | Cooper | ? |
| #2788 | Coos Haak | ? |
| #2789 | Copper Feet | Z |
| #19939 | Copy | - |
| #2790 | Copyright Control | Z |
| #2791 | Coral Software | Z |
| #2792 | Corgi Books | P |