| Ansh Creations Ltd | Information & communication | 2018 |
| Anstee Contracting Solutions Ltd | Construction | 2025 |
| Antea Construction Ltd | Construction | 2020 |
| Antholex Limited | Health & social care | 2022 |
| Anthony Jones (U.K.) Limited | Financial services | 1984 |
| Antios Multi-Concepts UK Ltd | Professional & scientific | 2022 |
| Antler Incorporated Ltd | Professional & scientific | 2022 |
| Antonio Property Experts Ltd | Households | 2024 |
| Antons Oak Interiors Limited | Wholesale & retail | 2003 |
| Antsam Properties Ltd | Real estate | 2025 |
| Anupama Homes Limited | Real estate | 2023 |
| ANY Drains Direct Limited | Construction | 2022 |
| ANY Events (London) Ltd | Professional & scientific | 2015 |
| ANY Type Shapewear Ltd | Other services | 2024 |
| Anyman Sauces Ltd | Manufacturing | 2026 |
| AO Property Wealth Partnerships Ltd | Real estate | 2018 |
| Aobproperty Ltd | Real estate | 2020 |
| AOD Properties Limited | Real estate | 2025 |
| Aodryliner Ltd | Construction | 2023 |
| AOO Real Estate Limited | Real estate | 2023 |
| AOT Investments Ltd | Financial services | 2025 |
| AP Derm Limited | Health & social care | 2023 |
| AP Venture Invest Ltd | Real estate | 2024 |
| APARTMENT47 Ltd | Real estate | 2019 |
| Apaura Consulting Ltd | Information & communication | 2025 |
| APE Property Management Ltd | Real estate | 2026 |
| Apex Airconditioning Services Limited | Construction | 2020 |
| Apex Cleaners Ltd | Administrative & support | 2025 |
| Apex Coating Services Limited | Construction | 1996 |
| Apex Control of Work Ltd | Professional & scientific | 2026 |
| Apex Education Recruitment Ltd | Administrative & support | 2019 |
| Apex Education Training Ltd | Administrative & support | 2013 |
| Apex Property Maintance Ltd | Construction | 2022 |
| Apex Recruitment Group Limited | Administrative & support | 2026 |
| Apex Residential & Commercial Ltd | Real estate | 2013 |
| Apexight Accounting Service Limited | Professional & scientific | 2019 |
| Apextech IT Consulting Limited | Information & communication | 2026 |
| Aphobos Crossfit Ltd | Arts & recreation | 2016 |
| Aphobos Sevenoaks Ltd | Arts & recreation | 2024 |
| Apis Contractings Ltd | Administrative & support | 2024 |
| APL Building Ltd | Construction | 2015 |
| Apollo Building Services Limited | Construction | 2008 |
| Apollo Commercial Cleaning Ltd | Other services | 2023 |
| Apollo Platforms Ltd | Administrative & support | 2024 |
| App Investments and Management Limited | Real estate | 2026 |
| Apparelly Limited | Wholesale & retail | 2016 |
| Apphiareli International Ltd | Wholesale & retail | 2020 |
| Appi Tutor Ltd | Education | 2023 |
| Applefields Management Company Limited | Households | 1991 |
| Appleville Innovations Technology Ltd | Information & communication | 2023 |
| Applify Limited | Arts & recreation | 2013 |
| Applycare.Io Ltd | Administrative & support | 2017 |
| Appmanevents Ltd | Information & communication | 2019 |
| Aprvd Limited | Information & communication | 2017 |
| APS Info Ltd | Information & communication | 2021 |
| Apstt Limited | Real estate | 2025 |
| Apstt Retail Ltd | Wholesale & retail | 2026 |
| Aqua CUT UK Ltd | Professional & scientific | 2004 |
| Aqualeaf Limited | Construction | 2012 |
| Aquarius Logistics Ltd | Transport & logistics | 2015 |
| Aquarius Multiservices Limited | Administrative & support | 2021 |
| Aquate Consultancy Ltd | Professional & scientific | 2012 |
| Aqumen Freight Management Limited | Transport & logistics | 2003 |
| Aqumen Logistics Ltd | Transport & logistics | 2005 |
| AR Design & Construction Ltd | Construction | 2020 |
| AR Developers Ltd | Real estate | 2014 |
| AR Estate Management Ltd | Real estate | 2025 |
| Araliconsults Limited | Construction | 2009 |
| Araoluwa Limited | Health & social care | 2024 |
| Aras Vildan Ltd | Other services | 2025 |
| Arasoft Ltd | Information & communication | 2025 |
| Arathee Limited | Administrative & support | 2018 |
| Arbortas Ltd | Agriculture & fishing | 2020 |
| ARC Network Productions Ltd | Information & communication | 2023 |
| Arc-Uk Technologies Limited | Professional & scientific | 2003 |
| Arch Way Restaurants & Bars Ltd | Hospitality | 2022 |
| Archie Sharp Limited | Arts & recreation | 2018 |
| Architects Atelier Ltd | Professional & scientific | 2013 |
| Arckod Consulting Ltd | Health & social care | 2023 |
| Arcmillan Limited | Administrative & support | 2012 |
| Arcot Limited | Administrative & support | 1998 |
| Ardas Property Ltd | Real estate | 2025 |
| Ardec Designs Ltd | Professional & scientific | 2011 |
| Ardian's Construction Group Ltd | Construction | 2025 |
| Ardit Construction Ltd | Construction | 2015 |
| Ardit Contractors Ltd | Construction | 2022 |
| Arell Fibre Ltd | Information & communication | 2022 |
| Arena Video Ltd | Administrative & support | 2022 |
| Areva Consultancy Limited | Information & communication | 2016 |
| Areva Limited | Information & communication | 2018 |
| Args Group Holdings Limited | Financial services | 2020 |
| ARI Prime Homes Ltd | Construction | 2023 |
| Aries Solutions Limited | Information & communication | 2010 |
| Arilex Consultancy Ltd | Professional & scientific | 2015 |
| Arish Engineering Ltd | Construction | 2015 |
| Ariyah Solutions Limited | Transport & logistics | 2020 |
| ARK Guard Ltd | Hospitality | 2021 |
| Arknoid Ltd | Professional & scientific | 2024 |
| Arlon Solutions Limited | Professional & scientific | 2026 |
| Arman Hotel Ltd | Hospitality | 2018 |