| A Rigby Contracting Ltd | Information & communication | 2018 |
| A S D Consultancy Ltd | Information & communication | 2007 |
| A S Equine Ltd | Agriculture & fishing | 2025 |
| A S K Properties Limited | Real estate | 1996 |
| A Sawdon Smith Ltd | Construction | 2020 |
| A Smart Phull Aluminium Bifolding Doors and Windows Ltd | Manufacturing | 2021 |
| A Solo Security Ltd | Administrative & support | 2023 |
| A Southern Plumbing & Heating Ltd | Construction | 2022 |
| A Spotless Office Limited | Administrative & support | 2025 |
| A Star Barbers MOH Ltd | Other services | 2025 |
| A Star Barbers RG2 Ltd | Other services | 2026 |
| A Star Executive Cars Ltd | Transport & logistics | 2023 |
| A Star Wheelchairs & Minibuses Limited | Transport & logistics | 2024 |
| A Starz Car Limited | Wholesale & retail | 2022 |
| A Stevanovic Limited | Information & communication | 2023 |
| A T Hope Limited | Construction | 2019 |
| A Tanner Limited | Construction | 2006 |
| A to Z Property Solutions Ltd | Construction | 2021 |
| A Type of Design Limited | Arts & recreation | 2014 |
| A Vida Fashion Limited | Manufacturing | 2007 |
| A Villa Property Solutions Ltd | Real estate | 2022 |
| A W Warwick Brickwork Limited | Construction | 2003 |
| A&A Advisory Partnership Ltd | Professional & scientific | 2020 |
| A&A Commercial Developments Limited | Real estate | 2025 |
| A&A Software Ltd | Administrative & support | 2017 |
| A&A Synergy Ltd | Real estate | 2024 |
| A&A Therapy Ltd | Health & social care | 2020 |
| A&B Roofing Limited | Construction | 2014 |
| A&D Car Sales Ltd | Wholesale & retail | 2017 |
| A&E Carpenters Ltd | Construction | 2024 |
| A&E Holdcroft Ltd | Hospitality | 2020 |
| A&G Airconditioning Ltd | Energy | 2022 |
| A&Gf Ltd | Households | 2005 |
| A&H 93 Construction Ltd | Construction | 2023 |
| A&J Properties Investments Ltd | Real estate | 2022 |
| A&J's Enterprise Limited | Other services | 2026 |
| A&K Auto Repair Ltd | Wholesale & retail | 2022 |
| A&M (Donnington) Parts Limited | Extraterritorial | 2019 |
| A&N Underfloor Heating Limited | Construction | 2023 |
| A&P Courier Ltd | Transport & logistics | 2019 |
| A&S Auto Care Centre Limited | Wholesale & retail | 2019 |
| A&S Bowes Thatching Limited | Construction | 2025 |
| A&S Property Development 214 Limited | Real estate | 2022 |
| A&S Property Solutions Limited | Real estate | 2018 |
| A&S Worldwide Trade UK Ltd | Wholesale & retail | 2014 |
| A&Sc Properties Limited | Real estate | 2026 |
| A&T Taxi Service Limited | Other services | 2025 |
| A&U Shehzadi Ltd | Wholesale & retail | 2023 |
| A&W Exporter Ltd | Wholesale & retail | 2019 |
| A&Z Mobiles UK Limited | Wholesale & retail | 2011 |
| A-Buy Ltd | Information & communication | 2013 |
| A-Design Gallery Ltd | Wholesale & retail | 2025 |
| A-S Building Services 2 Ltd | Construction | 2018 |
| A-Trax Group Ltd | Administrative & support | 2015 |
| A. Ballard Limited | Construction | 2017 |
| A. Bryan Builders Limited | Construction | 2003 |
| A. C. White Limited | Construction | 2021 |
| A. E. Petsche UK Limited | Wholesale & retail | 2011 |
| A. F. Jones Stonemasons Limited | Manufacturing | 2009 |
| A. Johnson Home Developments Ltd | Construction | 2017 |
| A. Karim Holdings Ltd | Real estate | 2020 |
| A. Karim M. Deen Imperium Ltd | Construction | 2023 |
| A. Langham Builders Limited | Construction | 2003 |
| A. Lusha Brickwork Ltd | Construction | 2021 |
| A. Manning Property Investments Limited | Real estate | 2016 |
| A.C.K.G Holdings Limited | Financial services | 2025 |
| A.D.J Film Limited | Information & communication | 2016 |
| A.G.M. Chilled Distribution Ltd | Transport & logistics | 2004 |
| A.J.Allen Ltd | Wholesale & retail | 2024 |
| A.J.Sellwood Contracting Ltd | Construction | 2013 |
| A.Muja Limited | Financial services | 2025 |
| A.P. Faulkner (Plumbing) Limited | Professional & scientific | 1981 |
| A.P. Faulkner Limited | Professional & scientific | 2014 |
| A.S Hygiene and Aesthetics Ltd | Health & social care | 2019 |
| A.S Telecommunications Ltd | Information & communication | 2024 |
| A.S.E Medical Group Ltd | Health & social care | 2023 |
| A.S.L Homes Limited | Real estate | 2021 |
| A1 Construction (Reading) Ltd | Construction | 2003 |
| A1 Discos Limited | Arts & recreation | 1998 |
| A1 Locksmiths (Berkshire) Limited | Administrative & support | 2006 |
| A1 Services PVT Ltd | Transport & logistics | 2015 |
| A1 Sovereign Limited | Manufacturing | 2006 |
| A1 Telecommunication Services Ltd | Information & communication | 2021 |
| A1POKA Ltd | Administrative & support | 2016 |
| A2 Investor Limited | Real estate | 2020 |
| A21 UK (Holdings) Limited | Extraterritorial | 2018 |
| A2B Swift Delivery Ltd | Transport & logistics | 2026 |
| A2BCLEANING Ltd | Wholesale & retail | 2025 |
| A2E Foods Ltd | Hospitality | 2023 |
| A2H Limited | Real estate | 2025 |
| A2K Hotels Ltd | Hospitality | 2022 |
| A2K Investments Limited | Financial services | 2013 |
| A2K Leisure LLP | | 2022 |
| A2K Properties Limited | Real estate | 2014 |
| A2Z Transport & Recovery Services Ltd | Wholesale & retail | 2025 |
| A3 Cloud Solutions Limited | Information & communication | 2021 |
| A3 Project Ltd | Wholesale & retail | 2015 |
| A3VOLUTION Limited | Information & communication | 2025 |
| A4 Autocentre Limited | Wholesale & retail | 2026 |
| A4 Bouncy Castles Ltd | Administrative & support | 2021 |