| Authority Hacker | |
| Autifony Therapeutics Ltd | |
| Auto Extract Systems Ltd | |
| Auto Marine Cables Ltd | Greater Manchester |
| Auto Mate Systems | |
| Auto Soft | Surrey |
| Auto Time Solutions Ltd | West Midlands |
| Auto Time Systems Northern Ltd | Greater Manchester |
| AutoAlert Ltd | |
| Autoblogging | |
| Autocab GPC Software Ltd | Greater Manchester |
| Autoclock Systems Ltd | |
| Autocom Products | Cambridgeshire |
| AutoConvert | |
| Autodata Products Ltd | |
| AutogenAI | |
| Autographic Insight | |
| AutoIt Consulting Ltd | |
| Automarine UK Ltd | |
| Automata | |
| Automated Architecture Ltd | |
| Automated Intelligence Ltd | Belfast |
| Automated Marketing System | Greater London |
| AutomatePro Ltd | |
| Automation Consultants Ltd | |
| Automation Ninjas | |
| Automation Solutions Ltd | Surrey |
| Automation Squared Ltd | |
| Automation Systems Integrators Ltd | |
| Automation Technologies Ltd | |
| Automations IO Ltd | |
| Autometers Systems Ltd | |
| Automise | |
| Automotive Software Solutions | |
| Automotive Transformation Group | |
| Autone | |
| Autonomic Co-operative Ltd | |
| Autonomous Flight | |
| Autopage Ltd | Norfolk |
| Autoplus | Cornwall |
| AutoRek | Glasgow |
| Autoscript | Greater London |
| Autoweb Design | |
| Autus Digital Agency UK | |
| AV Parts Master Ltd | Berkshire |
| AVA CAD/CAM Group Ltd | Cheshire |
| Avacta Life Sciences Ltd | |
| Avamae Software Solutions Ltd | |
| Avandda Ltd | Cheshire |
| Avantek Computer Ltd | Leicestershire |