| ANT Learning Education LLP | | 2017 |
| Antal Charitable Foundation Limited | Administrative & support | 2008 |
| Antal International Italy Limited | Administrative & support | 2006 |
| Antal International Limited | Administrative & support | 2006 |
| Antal International Network Limited | Administrative & support | 2000 |
| Antal Jobs Ltd | Professional & scientific | 2021 |
| Antal Recruitment Ltd | Administrative & support | 2020 |
| Antanova Ltd | Information & communication | 2005 |
| Antelope Properties Ltd | Real estate | 2022 |
| Anthem Clothing Ltd | Wholesale & retail | 2021 |
| Anti Reflective Film Limited | Wholesale & retail | 2026 |
| Antinous 333 Ltd | Other services | 2023 |
| Antiquarium Londinium Ltd | Wholesale & retail | 2025 |
| Antler First Holdings Limited | Financial services | 2021 |
| Antoinette Consulting Ltd | Information & communication | 2012 |
| Antro Limited | Administrative & support | 2017 |
| Antrouse Ltd | Administrative & support | 2018 |
| ANU Sols Ltd | Information & communication | 2026 |
| Anugrah Foods Ltd | Hospitality | 2024 |
| Anugrah Investments Ltd | Real estate | 2023 |
| Anugrah Limited | Wholesale & retail | 2017 |
| Anup Consulting Ltd | Information & communication | 2014 |
| Anup Rehab Ltd | Health & social care | 2023 |
| Anushtel Limited | Information & communication | 2017 |
| Anuuthi IT Services Ltd | Information & communication | 2022 |
| Anuuthi Limited | Real estate | 2019 |
| Anvcutting Limited | Other services | 2021 |
| Anvcutting Room Ltd | Other services | 2026 |
| Anya Limited | Wholesale & retail | 2024 |
| Anytime Clearances Ltd | Transport & logistics | 2023 |
| Anzen Dai-Ichi Ltd | Professional & scientific | 2025 |
| AO Advanced Ltd | Administrative & support | 2022 |
| Ao'Mahony Limited | Construction | 2015 |
| AOB Media Group Ltd | Information & communication | 2024 |
| AOD Couriers Limited | Transport & logistics | 2023 |
| AOI Properties Ltd | Real estate | 2023 |
| Aoife's Legacy Investement Limited | Real estate | 2022 |
| Aoisin Estates Limited | Real estate | 1998 |
| AOM Group Ltd | Real estate | 2026 |
| AP Consultant Ltd | Information & communication | 2020 |
| AP Consulting Limited | Professional & scientific | 2014 |
| AP Design and Build Ltd | Real estate | 2021 |
| AP Engineering Consultancy Services Ltd | Professional & scientific | 2023 |
| AP Engineering Services Ltd | Professional & scientific | 2019 |
| AP Global Resources Ltd | Wholesale & retail | 2023 |
| AP Luxury Assets Ltd | Wholesale & retail | 2024 |
| AP Property Holdings Limited | Real estate | 2015 |
| AP Rail Resources Ltd | Construction | 2017 |
| AP Tecnologies Limited | Information & communication | 2018 |
| Apala (UK) Limited | Administrative & support | 2024 |
| Apar International Ltd | Real estate | 2024 |
| Apayo Limited | Information & communication | 2017 |
| APC Cleaning Services Limited | Administrative & support | 2003 |
| Apex Design & Refurbishment Ltd | Construction | 2022 |
| Apex Flood Solutions Limited | Manufacturing | 2023 |
| Apex Haul Ltd | Transport & logistics | 2026 |
| Apex Protective Group Ltd | Wholesale & retail | 2023 |
| Apex Resources Group Ltd | Financial services | 2024 |
| Apex Resources Limited | Administrative & support | 2004 |
| APG PVT Limited | Real estate | 2020 |
| Aphrodite Holdings Limited | Financial services | 2020 |
| Aphs Herts Ltd | Professional & scientific | 2023 |
| APM Design and Build Limited | Construction | 2019 |
| APM Paint Specialists Ltd | Construction | 2023 |
| APN Properties Ltd | Real estate | 2018 |
| Apollo CIS Limited | Professional & scientific | 2014 |
| Apollo Communication Intelligence and Security Limited | Professional & scientific | 2014 |
| Apollo House Management Company Limited | Households | 1981 |
| Apollo Window Blinds Watford Ltd | Wholesale & retail | 2020 |
| App Abacus Limited | Information & communication | 2002 |
| Apparel 33 Limited | Wholesale & retail | 2020 |
| Appdrawn Ltd | Information & communication | 2016 |
| Apple Engineering Consultancy Ltd | Professional & scientific | 2023 |
| Apple Production Ltd | Administrative & support | 2023 |
| Apple Textile Limited | Wholesale & retail | 2022 |
| Apple Tree Design and Build Limited | Construction | 2023 |
| Applepeach Limited | Real estate | 2004 |
| Applette Limited | Information & communication | 2011 |
| Applewade Limited | Administrative & support | 1992 |
| Appoyo Limited | Information & communication | 2022 |
| Approved Traders Ltd | Wholesale & retail | 2023 |
| Appwill Company Ltd | Wholesale & retail | 2014 |
| Appz Solutions Limited | Information & communication | 2025 |
| APR Consultants Ltd | Administrative & support | 2016 |
| Apres Academy Ltd | Other services | 2026 |
| APS Livingstone Limited | Wholesale & retail | 2023 |
| APS Mechanical (Holdings) Limited | Real estate | 2020 |
| APS Talent Solutions Limited | Professional & scientific | 2009 |
| Apsak Limited | Real estate | 2020 |
| Apta Investments Limited | Real estate | 2018 |
| Apteligen Limited | Professional & scientific | 2010 |
| Aptus Heat Pumps Limited | Extraterritorial | 2012 |
| Apvans Express Ltd | Transport & logistics | 2025 |
| APW Consulting Limited | Information & communication | 2007 |
| Aqualux Properties Ltd | Real estate | 2026 |
| Aquamod Ltd | Construction | 2018 |
| Aquarius Capital Limited | Real estate | 2009 |
| Aquasolve Limited | Construction | 2025 |
| Aquilex Talent Ltd | Information & communication | 2022 |
| AR 786 Ltd | Construction | 2022 |