| Name | Region |
|---|---|
| Adalta | |
| Adam Appointments | |
| Adam Bradford Ltd | |
| ADAM Continuity | Hampshire |
| Adam Durrant | |
| Adam Matthew Digital Ltd | |
| ADAMAPP | |
| Adams Group | Kent |
| Adams IT Services UK | |
| Adao Ltd | |
| Adappt | Greater London |
| Adapt IT Recruitment Ltd | Buckinghamshire |
| Adapt Studios | |
| Adapt Worldwide | |
| Adaptatech | Greater London |
| Adaptavate Ltd | |
| Adaptavist Group Ltd | |
| Adaptive Automation | |
| Adaptive Conversions | Greater London |
| Adaptive Modules Ltd | East Sussex |
| Adaptive SEO | |
| Adaptive Web Ltd | Derbyshire |
| Adaptive Wireless Solutions Ltd | Oxfordshire |
| Adaptix Ltd | |
| Adaptsys Ltd | |
| Adarga | |
| Adastral Park | Suffolk |
| Adavatek | Wrexham County Borough |
| Adclear | |
| AdCombo | |
| Add Creative | Dorset |
| Add Jam | |
| Add People | Greater Manchester |
| Added Bytes Ltd | |
| Adder Technology Ltd | Cambridgeshire |
| ADdictive Digital Ltd | |
| Addictivity | Greater London |
| Addis Software plc | |
| Addition Design Ltd | |
| Addition Solutions | |
| Addmonte Ltd | |
| addmustard | |
| Addresscloud Ltd | |
| Addtime Recording Company Ltd | Greater Manchester |
| ADECS Ltd | West Midlands |
| Adelante | |
| Adelo | |
| Adelphi Automation Ltd | |
| Adendra Therapeutics Ltd | |
| Adenza |