| ID | Name | Type |
|---|---|---|
| #431 | Advanced Memory Systems Ltd | Z |
| #17029 | Adventure Exchange Club | U |
| #432 | Adventure International | P |
| #434 | Adventure Probe Software | Z |
| #17030 | Adventure Soft Mail Order | S |
| #435 | Adventure Software | Z |
| #436 | Adventure Writer | Z |
| #17915 | Adventure-Zone Software | Z |
| #17031 | Adventureline Club | U |
| #17033 | Adventurer's Guild | S |
| #437 | Adventurers Anonymous | Z |
| #438 | Adventuresoft UK Ltd | S |
| #439 | Adventureworld | Z |
| #19055 | Adventuron Software Ltd | P |
| #17034 | Afdec Electronics | H |
| #440 | Again Again | Z |
| #441 | Agatangelo Soler Montellano | ? |
| #442 | Agatha Christie | + |
| #443 | Agent-X | ? |
| #444 | Agnes Reisert | ? |