| ID | Name | Type |
|---|---|---|
| #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 |
| #16109 | Corin Howitt | + |
| #2793 | Corinne Stockley | ? |
| #17193 | Cornforth Marketing Services | M |
| #2794 | Cornhill Services | Z |
| #2795 | Cornsoft | Z |
| #2796 | Cornsoft Group Inc | Z |
| #21276 | Coronado Games | P |