| A&O Corsaire Ltd | Bracknell | 2015 |
| A&O Shared Solutions Limited | Bracknell | 2018 |
| A&P Collective Ltd | Petersfield | 2026 |
| A&P IT Solutions Ltd | Bournemouth | 2025 |
| A&P Network Solutions Ltd | Harlow | 2025 |
| A&P Systems Limited | Wellingborough | 2020 |
| A&Pp Home Solutions Ltd | Harrow | 2019 |
| A&R Films Limited | Stevenage | 2018 |
| A&R IT Consultancy Ltd | Solihull | 2016 |
| A&R Radar Ltd | Dorking | 2026 |
| A&S Global Ltd | London | 2022 |
| A&S Innovations Limited | Luton | 2014 |
| A&S IT Solutions Ltd | Halesowen | 2014 |
| A&S Media Ltd | 118-122 College Road | 2022 |
| A&S Morrow Ltd | Hove | 2013 |
| A&S Music Entertainment Ltd | Croydon | 2025 |
| A&S Private Limited | Milton Keynes | 2018 |
| A&S Signatures Ltd | Cullompton | 2024 |
| A&S Tech Solutions Ltd | Leicester | 2022 |
| A&S Trade Ltd | London | 2018 |
| A&S Worldwide Ltd | Barking | 2017 |
| A&T Business Insight Management Ltd | Birmingham | 2025 |
| A&T Constructions Company Ltd | London | 2025 |
| A&T Consultancies Limited | London | 2021 |
| A&T Consulting Ltd. | London | 2017 |
| A&T Digital Consultancy Ltd | London | 2019 |
| A&T Firm Ltd | London | 2025 |
| A&T IT Consultants Ltd | Gillingham | 2019 |
| A&T Labs Limited | Doncaster | 2025 |
| A&T Marketing Group Ltd | St. Albans | 2021 |
| A&T Software Ltd | Esher | 2022 |
| A&T UK Consulting Ltd | London | 2018 |
| A&T.Io Ltd | London | 2023 |
| A&U Services Limited | Bracknell | 2017 |
| A&V Group Ltd | Kington | 2023 |
| A&V Information Technology Consultancy Ltd. | Peterborough | 2017 |
| A&V Web Design Limited | Coulsdon | 2021 |
| A&V Worx Limited | Chester | 2026 |
| A&W Consultancy Services Ltd | Waterlooville | 2019 |
| A&W IT Consultancy Ltd | Redhill | 2022 |
| A&W Marketing Ltd | London | 2025 |
| A&X Limited | London | 2025 |
| A&Y Dynamics Ltd | Birmingham | 2025 |
| A&Y Education Ltd | Smethwick | 2019 |
| A&Z Labs Ltd | London | 2025 |
| A'Sheriv Intelligent Marine Technologies Ltd. | London | 2025 |
| A(I)Cademic Ltd | Seaford | 2024 |
| A+F Methods Limited | London | 2004 |
| A-2-SEA Solutions Limited | Romsey | 1996 |
| A-360 Data Ltd | Glasgow | 2022 |
| A-A-S-S Limited | Glasgow | 2025 |
| A-Algo Ltd | London | 2022 |
| A-Apps Limited | Durham | 2014 |
| A-Aston Technologies Limited | London | 2025 |
| A-B Labs Limited | London | 2023 |
| A-Buy Ltd | Reading | 2013 |
| A-Byte Computer Solutions Limited | Bishop Auckland | 2011 |
| A-C VFX Ltd | London | 2026 |
| A-Centre Ltd | Woking | 2015 |
| A-Commotion Limited | London | 2005 |
| A-Connect Ltd | St Ives | 2003 |
| A-Cube Ventures Limited | Bromley | 2024 |
| A-Cyber Solutions Ltd | Bury St. Edmunds | 2025 |
| A-Dept Creative Services Ltd | Cinderford | 2015 |
| A-Dex Prism Limited | Longfield | 2022 |
| A-Digital Works Ltd | London | 2023 |
| A-Dot Events & Publications Ltd | Glasgow | 2026 |
| A-Edge Systems Limited | Slough | 2012 |
| A-Futms Ltd | Belfast | 2025 |
| A-Game Commentary Ltd | Addlestone | 2025 |
| A-Hr.Pro Ltd | London | 2026 |
| A-Infinity Limited | London | 2005 |
| A-Lab Software Limited | Covent Garden | 2007 |
| A-Lab Solutions Limited | London | 2016 |
| A-Lan Solutions Ltd | Stockton On Tees | 2025 |
| A-Lan Technologies Ltd | Tunbridge Wells | 2023 |
| A-Level Software Limited | Surrey | 1996 |
| A-Line Creativity Ltd | Halifax | 2020 |
| A-Line Technical Services Limited | Lichfield | 2003 |
| A-List Film Production Pro Ltd | London | 2021 |
| A-List Productions Limited | Broxbourne | 2006 |
| A-List Records Global Ltd | Manchester | 2026 |
| A-Listware Ltd | St. Leonards-On-Sea | 2020 |
| A-Logics Ltd | East Ham | 2015 |
| A-Med Systems Limited | Milton Keynes | 2001 |
| A-Mnemonic Limited | London | 2013 |
| A-Muse Ltd | London | 2019 |
| A-Muse Services Ltd | Tadworth | 2026 |
| A-Object Consultancy Limited | Hounslow | 2017 |
| A-Ok Media House Ltd | Cardiff | 2016 |
| A-Oke Technologies & Consulting Ltd | Sutton | 2014 |
| A-Player AI Ltd | London | 2026 |
| A-Poj Limited | London | 2000 |
| A-Pro Consult Ltd | Belvedere | 2026 |
| A-Qub Ltd | Nottingham, | 2022 |
| A-S-L Computers Ltd. | Furzton | 2014 |
| A-Sarhan Ltd | Birmingham | 2024 |
| A-Sequence Limited | Swansea | 2018 |
| A-Side Studios Limited | Glasgow | 2008 |
| A-Sphere Insurance Software Limited | London | 2008 |