| Ammc Construction Ltd | Construction | 2025 |
| Among Bytes Ltd | Information & communication | 2017 |
| Ampelos London Ltd | Education | 2023 |
| AMS and Sons Limited | Health & social care | 2012 |
| Anagibb Limited | Wholesale & retail | 2010 |
| Anani Ltd | Health & social care | 2016 |
| Anatolian Trade Ltd | Wholesale & retail | 2024 |
| Anchor Car Park Limited | Hospitality | 2026 |
| Anchor Investments Holding Limited | Financial services | 2026 |
| Andrada's Fashion House Ltd | Manufacturing | 2022 |
| Anesti Kitchen Fitting Ltd | Construction | 2022 |
| Angel Base Limited | Real estate | 2026 |
| Angel Homes (V.G) Ltd | Health & social care | 2025 |
| Angela Swaan Ltd | Health & social care | 2021 |
| Anglo International School Ltd | Education | 2016 |
| Anibert Ltd | Transport & logistics | 2019 |
| Anja Middleton-Gayle Ltd | Health & social care | 2025 |
| Anme Properties Ltd | Real estate | 2022 |
| Anna Hursey Sports Management Limited | Arts & recreation | 2019 |
| Anna's Event Management Limited | Hospitality | 2018 |
| Another Beauty Supply Company Ltd | Wholesale & retail | 2021 |
| ANS Consultancy Services Ltd | Professional & scientific | 2024 |
| Ansell Resilience Consultancy Limited | Other services | 2025 |
| Ansp Ltd | Real estate | 2025 |
| ANT & Matt Limited | Administrative & support | 2017 |
| Antalyn Lettings Limited | Real estate | 2025 |
| Anthonia Childminder Limited | Health & social care | 2020 |
| Antonio Woodwork Limited | Manufacturing | 2023 |
| Ants Removals and Store Ltd | Transport & logistics | 2024 |
| Antvic RC Ltd | Construction | 2024 |
| Anuone Property Investment Ltd | Real estate | 2024 |
| ANY Telecom Ltd | Financial services | 2016 |
| Anya Group Limited | Wholesale & retail | 2023 |
| Anytimechildcare CIC | Health & social care | 2020 |
| AOA Testing Limited | Information & communication | 2015 |
| AOS Renewables Limited | Extraterritorial | 2012 |
| AP Renewable Ltd | Construction | 2026 |
| AP Square Ltd | Real estate | 2022 |
| APC Repairs Limited | Other services | 2007 |
| Apex Financial Consultants Ltd | Professional & scientific | 2024 |
| Apex Play & Leisure Ltd | Hospitality | 2026 |
| Apex Plumbing and Drainage Ltd | Water & waste | 2024 |
| Apex Renu Installations Limited | Construction | 2025 |
| Apex Search and Selection Consultancy Ltd | Professional & scientific | 2025 |
| APG Solutions Ltd | Real estate | 2021 |
| APM Utility Services Limited | Professional & scientific | 2012 |
| Apollo Labs BIO Tech UK Ltd | Professional & scientific | 2026 |
| Applewood Serviced Accommodation Ltd. | Real estate | 2021 |
| Aqua Core Plumbing & Heating Ltd | Construction | 2026 |
| AR Motors 1 Ltd | Wholesale & retail | 2022 |
| Aramaz Holding Limited | Financial services | 2025 |
| Archline Solutions Ltd | Professional & scientific | 2019 |
| Ardent Management (Holdings) Limited | Real estate | 2009 |
| Ardent Management Limited | Real estate | 1992 |
| Ardent Management NO.10 Limited | Financial services | 2021 |
| Ardent Management NO.11 Limited | Extraterritorial | 2022 |
| Ardent Management NO.4 Limited | Financial services | 2014 |
| Ardent Management NO.5 Limited | Financial services | 2015 |
| Ardent Management NO.6 Limited | Financial services | 2018 |
| Ardent Management NO.7 Limited | Financial services | 2018 |
| Ardent Management NO.8 Limited | Financial services | 2020 |
| Ardent Management NO.9 Limited | Financial services | 2020 |
| Areca Limited | Health & social care | 2021 |
| Areti Investments Ltd | Real estate | 2024 |
| ARF Consulting Services Ltd | Professional & scientific | 2025 |
| ARF Ltd | Real estate | 2017 |
| Argentum Tech Ltd | Wholesale & retail | 2021 |
| Arhaariya Ltd | Wholesale & retail | 2022 |
| Arin Kemal Ltd | Real estate | 2026 |
| Aristoren Filmworks Ltd | Arts & recreation | 2017 |
| ARK Elite Ltd | Professional & scientific | 2025 |
| Arkle Vass Ltd | Construction | 2016 |
| Armada Services Limited | Information & communication | 2015 |
| Aroma WBY Ltd. | Hospitality | 2017 |
| Aroma&Love Limited | Manufacturing | 2025 |
| Arrange Finance Limited | Real estate | 2018 |
| Arro Food & Wine Ltd | Wholesale & retail | 2018 |
| Artemis Cloud Services LLP | | 2021 |
| Artemis Network Services Ltd | Other services | 2017 |
| Artisan Place Residents Management Company Limited | Households | 2014 |
| Artwood Design Ltd | Manufacturing | 2012 |
| Arvos Ventures Ltd | Real estate | 2025 |
| Arvus Holdings Limited | Financial services | 2024 |
| AS Rack Ltd | Hospitality | 2026 |
| As&I Group Limited | Professional & scientific | 2023 |
| ASA Fast Food Limited | Hospitality | 2018 |
| ASA Investments London Ltd | Real estate | 2024 |
| ASC Services Limited | Professional & scientific | 2024 |
| Ascend Build Group Ltd | Construction | 2026 |
| Ascl Ltd | Real estate | 2025 |
| Asey Accountancy Ltd | Professional & scientific | 2025 |
| Asgard Vehicle Rentals Limited | Administrative & support | 1999 |
| ASH Investment Holdings Ltd | Administrative & support | 2016 |
| Ashbourne Residents Management Company Limited | Real estate | 2005 |
| Ashcroft Group Ltd | Construction | 2020 |
| Ashmark Estate Management Ltd | Real estate | 2016 |
| Ashoka Lighting Ltd | Wholesale & retail | 2025 |
| Ashvin Property Ltd | Real estate | 2018 |
| ASK Building (London) Limited | Construction | 2021 |
| ASK Investment Properties Ltd | Real estate | 2026 |