| Anthony Jefferies Ltd | Professional & scientific | 2025 |
| Anthony Urquhart Limited | Transport & logistics | 2025 |
| Antony Charles Treescapes Limited | Agriculture & fishing | 2011 |
| Antylia Ltd | Wholesale & retail | 2023 |
| ANU Beauty Studio Limited | Other services | 2025 |
| Anvil & IVY Ltd | Manufacturing | 2026 |
| Anvil Alloys Limited | Manufacturing | 2017 |
| Anwar & Hassan Co Ltd | Health & social care | 2017 |
| Anwar & Hassan Property Ltd | Real estate | 2025 |
| Anwar Holdings Ltd | Professional & scientific | 2020 |
| ANY Day Travel Ltd | Transport & logistics | 2024 |
| Anyaria Limited | Education | 2022 |
| ANYTHING2U Ltd | Manufacturing | 2022 |
| Anytime Health Care and Cleaners Ltd | Extraterritorial | 2019 |
| Anytime Plant Ltd | Administrative & support | 2021 |
| AOK Tyres Ltd | Wholesale & retail | 2021 |
| AOS Stores Ltd. | Wholesale & retail | 2016 |
| AOW Properties Ltd | Real estate | 2024 |
| AP Cleaning Worldwide Ltd | Administrative & support | 2025 |
| AP Housing PVT Ltd | Real estate | 2025 |
| AP Property Partners Limited | Real estate | 2025 |
| AP Rail Installations Limited | Administrative & support | 2016 |
| AP Worldwide U.K. Ltd | Transport & logistics | 2025 |
| Apache England Limited | Professional & scientific | 2025 |
| Apal Media Ltd | Information & communication | 2022 |
| Apal Products Ltd | Wholesale & retail | 2022 |
| APB Commercial Consultants Ltd | Other services | 2025 |
| APD Technologies Limited | Wholesale & retail | 2015 |
| Apdr Holdings Limited | Information & communication | 2020 |
| Aperta Property Solutions Limited | Real estate | 2025 |
| Apex Agencies International Limited | Other services | 1983 |
| Apex Close Protection Ltd | Public administration | 2025 |
| Apex Consultancy & Training Services Limited | Education | 2016 |
| Apex Driver & Rider Training Ltd | Education | 2019 |
| Apex Electrical Engineering Ltd | Construction | 2026 |
| Apex House Rentals Ltd | Real estate | 2023 |
| Apex Independent Academy Ltd | Education | 2024 |
| Apex Mini Buses Ltd | Transport & logistics | 2026 |
| Apex Power Gym Ltd | Arts & recreation | 2026 |
| Apex Services London Ltd | Administrative & support | 2020 |
| Apex Smart Ltd | Wholesale & retail | 2025 |
| Apex Training and Assessment Ltd | Education | 2025 |
| APEX-1 UK Security Ltd | Administrative & support | 2023 |
| Aphanite Ltd | Real estate | 2019 |
| APL Formwork Group Limited | Manufacturing | 2013 |
| APL Formwork Limited | Manufacturing | 2007 |
| Apms Healthcare Limited | Real estate | 2012 |
| Apna Adda Ltd | Hospitality | 2022 |
| Apogem Travel Agency Ltd | Information & communication | 2019 |
| Apollo Pools Limited | Education | 2023 |
| Apollo Stone Tops Limited | Wholesale & retail | 2025 |
| Apollo Tax Services Limited | Professional & scientific | 2010 |
| Apostolic Faith Mission Birmingham Central Assembly Limited | Other services | 2006 |
| Apostosy Jewels Ltd | Wholesale & retail | 2024 |
| Apotheker Limited | Health & social care | 2015 |
| App Carz Limited | Administrative & support | 2007 |
| Apple Interior & Exhibition Design Ltd | Administrative & support | 2003 |
| Appledore Court RTM Company Limited | Real estate | 2014 |
| Applied Chemicals UK Limited | Extraterritorial | 2007 |
| APR Studios Limited | Arts & recreation | 2025 |
| Aprilbtevents Ltd | Hospitality | 2025 |
| APS BH Ltd | Health & social care | 2021 |
| APS Studios Ltd | Information & communication | 2019 |
| Aptec Solutions Limited | Information & communication | 2015 |
| APW Home Improvements Limited | Construction | 2025 |
| APW Warm Roof Systems Limited | Construction | 2025 |
| AQ Cricket Foundation CIC | Education | 2025 |
| AQ Group Services Ltd | Health & social care | 2026 |
| Aqpvz Constructionsz Limited | Construction | 2025 |
| Aqua Install Limited | Wholesale & retail | 2012 |
| Aqua Linen Commercial Laundry Limited | Other services | 2006 |
| Aqua Plumbing & Heating Services Ltd | Construction | 2000 |
| Aqua Utility Engineering Ltd | Construction | 2026 |
| Aquacise Limited | Education | 2005 |
| Aquadition Limited | Construction | 1997 |
| Aquaflame Systems Limited | Extraterritorial | 2021 |
| Aquagas Plumbing and Heating Limited | Construction | 2005 |
| Aquainvest Acquisitions Limited | Professional & scientific | 2004 |
| Aquainvest Holding Company Limited | Professional & scientific | 2004 |
| Aquainvest Ventures Limited | Professional & scientific | 2004 |
| Aqualibra Limited | Real estate | 2002 |
| Aqualuxuk Ltd | Wholesale & retail | 2025 |
| Aquapaw Ltd | Wholesale & retail | 2025 |
| Aquastations Water Coolers Limited | Administrative & support | 2009 |
| Aquaven Ltd | Extraterritorial | 2000 |
| AR 1 Holdings Ltd | Real estate | 2023 |
| AR 91 Ltd | Real estate | 2025 |
| AR Build Solutions Ltd | Construction | 2023 |
| AR Claims Management Limited | Other services | 2020 |
| AR Detailing Club Ltd | Administrative & support | 2025 |
| AR Inventors Ltd | Wholesale & retail | 2025 |
| AR MLC Limited | Professional & scientific | 2017 |
| AR Tooling Ltd | Wholesale & retail | 2024 |
| Ar-Hg Limited | Real estate | 2021 |
| Ar-Rahmaan Properties Ltd | Real estate | 2023 |
| AR. Walsall Properties Ltd | Real estate | 2024 |
| Ar.Walsall Motors Ltd | Wholesale & retail | 2014 |
| AR1 Enterprises Ltd | Wholesale & retail | 2026 |
| Arainretail Ltd | Wholesale & retail | 2025 |
| Arbor Bookkeeping Ltd | Professional & scientific | 2023 |