| AGF Survey Supply Ltd | Wholesale & retail | 2017 |
| Aggarwal Advisory Services Limited | Health & social care | 2018 |
| Aggarwal Services Limited | Health & social care | 2008 |
| Agglomeration Ltd | Administrative & support | 2024 |
| Aggregate Sand Gravel Ltd | Wholesale & retail | 2026 |
| Aggressive Limited | Professional & scientific | 2013 |
| Aggressive Perimeter Security Ltd | Administrative & support | 2025 |
| AGH Infection Control Services Limited | Health & social care | 2015 |
| Agha Lounge Limited | Hospitality | 2019 |
| Aghoco 1337 Limited | Information & communication | 2015 |
| Aghoco 1952 Limited | Extraterritorial | 2020 |
| Agile Adoption Ltd | Information & communication | 2018 |
| Agile Cybersecurity Ltd | Administrative & support | 2024 |
| Agile Financial Solutions Limited | Extraterritorial | 2018 |
| Agile Property Investments Limited | Real estate | 2021 |
| Agilesurgical Limited | Health & social care | 2016 |
| Agilio Software Bidco Limited | Financial services | 2019 |
| Agilio Software Topco Limited | Financial services | 2019 |
| Agincourt Advisors Ltd | Professional & scientific | 2021 |
| AGK Traders Ltd | Manufacturing | 2026 |
| AGM Project Management Ltd | Professional & scientific | 2022 |
| Agma Services Limited | Public administration | 2019 |
| AGN Ventures Ltd | Real estate | 2024 |
| Agni Foods Limited | Extraterritorial | 2021 |
| Agni Trading Limited | Wholesale & retail | 2024 |
| Agnw Group Ltd | Hospitality | 2025 |
| Agora Bidco Limited | Financial services | 2020 |
| Agora Midco 2 Limited | Extraterritorial | 2021 |
| Agora Midco Limited | Extraterritorial | 2021 |
| Agora Topco Limited | Extraterritorial | 2021 |
| AGP BIO Limited | Professional & scientific | 2009 |
| Agrawall Limited | Health & social care | 2023 |
| Agricorp Group Limited | Administrative & support | 2025 |
| Agrimark Limited | Wholesale & retail | 2007 |
| Agrimark Trailers Limited | Extraterritorial | 2002 |
| Agriplant Vehicle Services Limited | Wholesale & retail | 1998 |
| Agromykos Limited | Agriculture & fishing | 2023 |
| AGS Care Consultancy Limited | Real estate | 2022 |
| AGS Construction Limited | Construction | 2016 |
| AGS Hospitality Ltd | Hospitality | 2021 |
| Agsg Group Ltd | Professional & scientific | 2023 |
| AGT Richardson Ltd | Real estate | 2026 |
| Aguachem Holdings Ltd | Financial services | 2025 |
| Aguachem Ltd | Water & waste | 2004 |
| Aguilarity Limited | Other services | 2025 |
| AH (REC) Ltd | Administrative & support | 2010 |
| AH (Yorkshire) Limited | Other services | 2019 |
| AH Accessories Limited | Wholesale & retail | 2024 |
| AH Development Healthcare Limited | Manufacturing | 2024 |
| AH Investment Group Ltd | Real estate | 2025 |
| AH Logistics Wholesale Ltd | Wholesale & retail | 2007 |
| AH Medical Limited | Health & social care | 2019 |
| AH Proxima Limited | Wholesale & retail | 2025 |
| AHA (UK) Limited | Professional & scientific | 2015 |
| AHA Analytics Ltd | Information & communication | 2016 |
| AHA UK Trading Limited | Wholesale & retail | 2024 |
| Ahad Tandoori Restaurant Limited | Hospitality | 1999 |
| Ahava Vivere Victus Ltd | Health & social care | 2025 |
| AHB Properties Ltd | Households | 2018 |
| AHH Midco 1 Limited | Financial services | 2022 |
| AHH Midco 2 Limited | Financial services | 2022 |
| AHI Aurin Limited | Real estate | 2024 |
| AHI Properties Ltd | Real estate | 2021 |
| AHJ Wealth Management Ltd | Financial services | 2014 |
| AHJ Wills & Estates Ltd | Professional & scientific | 2021 |
| Ahmad Tanwir Locums Ltd | Health & social care | 2018 |
| Ahmadi Ltd | Real estate | 2018 |
| Ahmads Shop Ltd | Wholesale & retail | 2026 |
| Ahmadsalis Limited | Wholesale & retail | 2025 |
| Ahmed Realty Group Ltd | Real estate | 2023 |
| Ahmed Yasin Ltd | Wholesale & retail | 2025 |
| Ahmed's Deliveries Limited | Transport & logistics | 2025 |
| Ahods Holdings SR Limited | Real estate | 2024 |
| AHS Smiles Ltd | Health & social care | 2023 |
| Ahs-H Limited | Professional & scientific | 2026 |
| Ahsdigital Ltd | Wholesale & retail | 2021 |
| AHT Riverside Properties Ltd | Real estate | 2020 |
| Ahzerclothing Limited | Other services | 2025 |
| AI Automate Ltd | Information & communication | 2024 |
| AI Convergence Limited | Administrative & support | 2024 |
| AI Coverage Solutions Limited | Information & communication | 2026 |
| AI DEV Studio Ltd | Professional & scientific | 2026 |
| AI Merchants Ltd | Wholesale & retail | 2023 |
| AI Pharm (Sheffield) Limited | Health & social care | 2022 |
| AI Portraiture Ltd | Arts & recreation | 2025 |
| AI Telecoms Ltd | Information & communication | 2024 |
| Aial Limited | Administrative & support | 1998 |
| AIC Consultants Ltd | Professional & scientific | 2021 |
| Aidan Foods Ltd | Hospitality | 2026 |
| Aidan Homes Limited | Real estate | 2021 |
| Aiden’S Barber Limited | Other services | 2019 |
| Aifa B. & Aquaa 29 Limited | Manufacturing | 2025 |
| Aigem Ltd | Information & communication | 2025 |
| Aijia Ceramics UK Ltd | Wholesale & retail | 2015 |
| Aiken Fleet Services Limited | Wholesale & retail | 2021 |
| Aiktom Digital Ltd | Information & communication | 2025 |
| Aikz Ltd | Hospitality | 2024 |
| Ailerondwarf Ltd | Information & communication | 2021 |
| Ailsa Barr Consultancy Ltd | Professional & scientific | 2025 |
| AIM 4 Growth Limited | Real estate | 2001 |