| Anatec BI | Berkshire |
| Anatomise Biostats | |
| ANB Software Ltd | South Yorkshire |
| Ancoris Ltd | Berkshire |
| AND Digital | |
| Andalay Technologies | |
| Anderson IT Consulting | Oxfordshire |
| Anderson Stockley Accredited Training Ltd | |
| Andica Ltd | Buckinghamshire |
| Andover College | |
| Andpartnership | |
| Andre Armacollo | Greater London |
| Andrew Backhouse | |
| Andrew Burdett Design | Derbyshire |
| Andrew Lock | |
| Andrews & Arnold Ltd | Berkshire |
| Andrews Computer Services Ltd | Hertfordshire |
| Andy Morley | Derbyshire |
| Andy Pike Ltd | Surrey |
| Anexsys Ltd | |
| Angel Digital Marketing | Nottinghamshire |
| Angel Investment Network Ltd | |
| Angel Solutions Ltd | Merseyside |
| Angell & Co. | |
| Angello | |
| Angels Den | |
| Angels in MedCity | |
| Angels Media Ltd | |
| Angels Partners | |
| Angiodesign (UK) Ltd | |
| Angle plc | |
| Angle Studios | |
| Anglia Research Services | |
| Anglia Ruskin University | Cambridgeshire |
| Anglia Ruskin University - Computing and Information Science | Cambridgeshire |
| Anglia Telephones | Norfolk |
| Anglian Internet | |
| Anglian Internet Ltd | Norfolk |
| Anglian Linux User Group | Norfolk |
| Angular UK Opco Ltd | |
| Anicca Digital | |
| Anika Digital | |
| Animacs | Cambridgeshire |
| Animal Systems Ltd | Wiltshire |
| Animated Technologies Ltd | |
| Animo Consultancy | |
| Animorph Ltd | |
| Animus Technology | |
| Animus Technology | |
| ANNA | |