| Amzom Ltd | Information & communication | 2024 |
| AN Market Ltd | Wholesale & retail | 2017 |
| Anabra Ltd | Hospitality | 2020 |
| Anchor Property Holdings Limited | Financial services | 2003 |
| Anchor Support Services Limited | Health & social care | 2008 |
| Andeevs Limited | Wholesale & retail | 2006 |
| Anderson Phillips Accountants Limited | Professional & scientific | 2006 |
| Anderson Phillips Legal Services Ltd | Financial services | 2014 |
| Andrew Burford Stunts Ltd | Administrative & support | 2011 |
| Andrew Prosser Consulting Limited | Professional & scientific | 2019 |
| Andy's Automatics Ltd | Education | 2025 |
| Angel PSV Transport Ltd | Transport & logistics | 2025 |
| Angell Compliance Services Ltd | Professional & scientific | 2026 |
| Angels Property Ventures Ltd | Real estate | 2026 |
| Angletwich Financial Limited | Financial services | 2019 |
| Anhub Construction Ltd | Construction | 2024 |
| ANI Cleaning Solutions Ltd | Administrative & support | 2018 |
| Aniv Trans Ltd | Construction | 2011 |
| Anje Oppong Ltd | Other services | 2021 |
| Ankara Festival UK Ltd | Administrative & support | 2026 |
| Anlo Solutions Ltd | Professional & scientific | 2026 |
| Anne Janu Limited | Hospitality | 2026 |
| Annkeade Ltd | Health & social care | 2023 |
| Annkyra Limited | Real estate | 2024 |
| Anoa Consulting Limited | Professional & scientific | 2018 |
| Anode Outlet Limited | Wholesale & retail | 2022 |
| Ansonics Consulting Ltd | Professional & scientific | 2016 |
| Antech Services (UK) Ltd | Wholesale & retail | 2006 |
| Antmas Services Limited | Construction | 2014 |
| AOB Ventures Ltd | Professional & scientific | 2019 |
| AOI Enterprise Limited | Public administration | 2025 |
| AOJ Ventures Ltd | Information & communication | 2024 |
| AOL Investment Limited | Professional & scientific | 2020 |
| AP SD Nineteen Limited | Wholesale & retail | 2025 |
| AP Trees (Kent) Limited | Agriculture & fishing | 2017 |
| Apal Limited | Professional & scientific | 2015 |
| APB Project Solutions Ltd | Construction | 2017 |
| APC Technology Group Ltd | Professional & scientific | 1982 |
| APE Harrison Billet Ltd. | Manufacturing | 2005 |
| Apec Solutions Ltd | Professional & scientific | 2023 |
| Apex Carpentery Ltd | Construction | 2025 |
| Apex Crestfield Limited | Financial services | 2026 |
| Apex Pipework Ltd | Construction | 2020 |
| Apex Platforms Ltd | Wholesale & retail | 2018 |
| Apex Technical Consultants Ltd | Manufacturing | 2023 |
| Apex Vitals Limited | Wholesale & retail | 2014 |
| Apexone Property Services Limited | Real estate | 2026 |
| APG Topco Ltd | Professional & scientific | 2022 |
| APL Group Holdings Ltd | Financial services | 2023 |
| Apollo View Modular Ltd | Manufacturing | 2022 |
| Apos Dyne Ltd | Hospitality | 2025 |
| Appliance Care Experts (Ace) Limited | Other services | 2025 |
| Appropriate Training & Consultancy Ltd | Professional & scientific | 2021 |
| Appy Foods Ltd | Information & communication | 2019 |
| APR Property Maintenance Ltd | Construction | 2024 |
| APS 2024 Ltd | Transport & logistics | 2024 |
| APS C/T Properties Limited | Real estate | 2003 |
| APS Casino Properties Limited | Real estate | 2003 |
| APS Height Access Ltd. | Construction | 2013 |
| APS Inn Properties Limited | Real estate | 2003 |
| APS Park and Hire Limited | Other services | 2003 |
| Aquality Ltd | Extraterritorial | 2014 |
| Aquarius (Medway) Limited | Real estate | 2020 |
| AR Dream Homes Limited | Real estate | 2025 |
| AR Farming Ltd | Agriculture & fishing | 2020 |
| AR Lingo Ltd | Professional & scientific | 2025 |
| Aradee Restoration Limited | Administrative & support | 2025 |
| Aramide Consulting Limited | Information & communication | 2007 |
| Arbill Ltd | Real estate | 2024 |
| ARC Technics Ltd | Professional & scientific | 2024 |
| Arcade Finance Ltd | Professional & scientific | 2020 |
| Arcadia Carpets and Flooring Ltd | Construction | 2025 |
| Arcadia Contract Flooring Limited | Construction | 2014 |
| Arcflex Hose & Bellows Limited | Manufacturing | 1987 |
| Archie Bailey Limited | Real estate | 2016 |
| Arctic G Ltd | Manufacturing | 2025 |
| Arcview Ltd | Information & communication | 2025 |
| Ardomestic and Commercial Ltd | Water & waste | 2026 |
| ARF Media Limited | Information & communication | 2024 |
| Argb Ground Transport Ltd | Transport & logistics | 2022 |
| ARI & TEE Limited | Administrative & support | 2024 |
| Aria Enterprises Ltd | Wholesale & retail | 2024 |
| Ariella Holding Limited | Financial services | 2024 |
| Arjun Investments Limited | Real estate | 2025 |
| ARK Architectural Design Services Limited | Professional & scientific | 2021 |
| ARK Hill Developments Ltd | Construction | 2025 |
| Armac Shipping Services Ltd | Transport & logistics | 2007 |
| Armour Glazing Limited | Construction | 2026 |
| Arnies Snack Bar Limited | Hospitality | 2019 |
| Aroma Beauty Bar Ltd | Other services | 2019 |
| Aroma Theory Ltd | Manufacturing | 2021 |
| Arpenteur Nightingale Limited | Real estate | 2022 |
| Arriba Services Ltd | Professional & scientific | 2024 |
| Arrow Flooring Services Ltd | Construction | 2023 |
| Arrowteam Limited | Hospitality | 2003 |
| Arsto Ltd | Wholesale & retail | 2017 |
| Artemis Electrical and Building Ltd | Construction | 2023 |
| Arter & Company Ltd | Professional & scientific | 2006 |
| Artesian ENF Therapuetix Ltd | Professional & scientific | 2025 |
| Artisano (Rochester) Ltd | Hospitality | 2023 |