| Artisan and Reenactors Market Ltd | Wholesale & retail | 2024 |
| Artisan Spice Ltd | Hospitality | 2019 |
| Artstribe Ltd | Wholesale & retail | 2026 |
| AS Healthcare Services Limited | Health & social care | 2024 |
| AS Social Care Limited | Health & social care | 2013 |
| AS Time Goes by Memorials Ltd | Other services | 2022 |
| As&Ib Food Ltd | Hospitality | 2026 |
| Asad Property Management Limited | Real estate | 2023 |
| ASB Mechanical Services Limited | Construction | 2024 |
| ASB Woodburners Limited | Administrative & support | 2018 |
| Ascendant Software Ltd | Information & communication | 2019 |
| ASD Distribution Ltd | Wholesale & retail | 1998 |
| ASH Automobile Ltd | Wholesale & retail | 2020 |
| ASH Electrical Installation Ltd | Construction | 2025 |
| Ashaz Express Ltd | Transport & logistics | 2026 |
| Ashby Creative Ltd | Professional & scientific | 2019 |
| Ashcroft Mailing Solutions Limited | Transport & logistics | 1998 |
| Ashfee Co Ltd | Wholesale & retail | 2025 |
| Ashleigh Works Ltd | Construction | 2021 |
| Ashton Property Rental Ltd | Real estate | 2020 |
| ASJ PAT Testing Limited | Professional & scientific | 2013 |
| ASK Annie Ltd | Hospitality | 2019 |
| Askpertask Services Ltd | Information & communication | 2025 |
| ASP Promotions Limited | Wholesale & retail | 2005 |
| Aspen Williams Recruitment Limited | Administrative & support | 2015 |
| Aspire DDA Limited | Administrative & support | 2011 |
| Aspro Contractors Ltd | Construction | 2014 |
| Association for Student Residential Accommodation | Other services | 2021 |
| Association of Land Rover Clubs Limited | Arts & recreation | 1984 |
| Association of Rover Clubs Limited | Extraterritorial | 2001 |
| Assured Wills, Trusts and Estate Planning Ltd | Professional & scientific | 2020 |
| AST Tools Ltd | Real estate | 2000 |
| Astin & Co Limited | Wholesale & retail | 2026 |
| Astin Fresh Limited | Wholesale & retail | 2025 |
| Astin Investments Ltd | Real estate | 2025 |
| Astin Mart Limited | Wholesale & retail | 2025 |
| Astin Overseas Consultants Limited | Education | 2021 |
| Astin Retail Ltd | Wholesale & retail | 2021 |
| Astinmartandco Ltd | Wholesale & retail | 2024 |
| Astwood (White Lion) Management Limited | Households | 2016 |
| Astwood 4 X 4 Limited | Wholesale & retail | 2015 |
| Astwood Bank Community Group Community Interest Company | Other services | 2019 |
| Astwood Cattery Limited | Agriculture & fishing | 2017 |
| Astwood Grange Residents' Association Limited | Households | 2005 |
| Astwood Heritage Limited | Wholesale & retail | 2019 |
| Astwood HS Ltd | Hospitality | 2021 |
| Astwood Landscapes & Driveways Ltd | Administrative & support | 2020 |
| Astwood Law Limited | Other services | 2012 |
| Astwood Livery Limited | Agriculture & fishing | 2008 |
| Astwood Osteopaths Limited | Health & social care | 2005 |
| Astwood Projects Limited | Professional & scientific | 2008 |
| Astwood Property Management Limited | Real estate | 2018 |
| Astwood QA Services Limited | Information & communication | 2017 |
| Astwood Service Centre Limited | Wholesale & retail | 2006 |
| Astwoods Construction Group Limited | Construction | 2014 |
| ASW Clothing Limited | Wholesale & retail | 2026 |
| ATC MOT Limited | Wholesale & retail | 2022 |
| Ateq UK Limited | Manufacturing | 1994 |
| Athena Aesthetics and Beauty Limited | Other services | 2018 |
| Athena Beauty Academy Ltd | Other services | 2019 |
| Athena Health, Well-Being and Performance Solutions CIC | Health & social care | 2024 |
| Athena Performance Ltd | Arts & recreation | 2021 |
| Athenalearn Limited | Education | 2025 |
| Atif Trading Ltd | Hospitality | 2023 |
| Atkins Search Limited | Administrative & support | 2016 |
| Atlas Container Line Limited | Extraterritorial | 1995 |
| Atlas Handling (UK) Limited | Wholesale & retail | 2001 |
| Atlaswkg Ltd | Professional & scientific | 2023 |
| Atom Displays Limited | Professional & scientific | 2017 |
| Atrium Land & Property Limited | Real estate | 2016 |
| ATS Pubs Ltd | Hospitality | 2025 |
| Attensys Limited | Administrative & support | 2025 |
| Attwell Family Investment Company Limited | Financial services | 2021 |
| Attwell Farm Limited | Agriculture & fishing | 1998 |
| AU Sports Ltd | Arts & recreation | 2013 |
| Aubreyavenue Property Ltd | Real estate | 2019 |
| Auchlossan Limited | Real estate | 2018 |
| Aura Works Limited | Construction | 2018 |
| Ausum Inc Limited | Real estate | 2022 |
| Auto Aircon (UK) Ltd | Wholesale & retail | 1999 |
| Auto Electrics (Redditch) Holdings Limited | Real estate | 2021 |
| Auto Electrics (Redditch) Limited | Wholesale & retail | 2005 |
| Autoconnect Limited | Information & communication | 1997 |
| Autofile Limited | Information & communication | 2023 |
| Autominate Limited | Information & communication | 2023 |
| Autosanctum Ltd | Transport & logistics | 2026 |
| Autotech MOT Centre Ltd | Wholesale & retail | 2010 |
| Autoworld Media Limited | Information & communication | 2021 |
| Av-Ex Logistics Ltd | Transport & logistics | 2023 |
| Ava-Matic (U.K.) Limited | Manufacturing | 1988 |
| Avancer Cars and Commercials Limited | Wholesale & retail | 2019 |
| Avancer Holdings Limited | Financial services | 2018 |
| Avancer Transport and Maintenance Limited | Wholesale & retail | 2011 |
| Avayler Holdings Limited | Financial services | 2023 |
| Avayler Trading Limited | Information & communication | 2021 |
| Avgo Group Ltd | Real estate | 2019 |
| Avian Remote Consulting Limited | Professional & scientific | 2025 |
| Avicenna Healthcare International Limited | Manufacturing | 2021 |
| Avicenna Surgical Limited | Manufacturing | 2014 |
| Aviguard Network Limited | Agriculture & fishing | 2026 |