| Arjuna Fine Arts Studio London Limited | Arts & recreation | 2024 |
| ARK Retail Shop Ltd | Wholesale & retail | 2017 |
| Arkham London Ltd | Real estate | 2025 |
| Arkham Services Ltd | Construction | 2018 |
| Arkill Court Management Company Limited | Households | 1995 |
| Arkizo Limited | Wholesale & retail | 2025 |
| Arkley Automotive Ltd | Wholesale & retail | 2022 |
| Arlavicius Limited | Wholesale & retail | 2024 |
| Arlepo Childcare Ltd | Health & social care | 2022 |
| Arlesey Fish & Chips Ltd | Hospitality | 2023 |
| Armaan Creations Ltd | Information & communication | 2025 |
| Armani Bodywork Ltd | Wholesale & retail | 2022 |
| Armaro Ltd | Construction | 2025 |
| Armer Fit Limited | Other services | 2014 |
| Armina Holdings Ltd | Financial services | 2024 |
| Armour Electrical Services Ltd | Manufacturing | 2020 |
| ARO Foods Limited | Hospitality | 2025 |
| Aroda Limited | Professional & scientific | 2020 |
| Arom Construction Ltd | Construction | 2025 |
| Aroma Line Ltd | Wholesale & retail | 2025 |
| Aropp Ltd | Real estate | 2013 |
| Arotec Neon Signs Ltd | Other services | 2003 |
| Array Holdings(Uk) Ltd | Professional & scientific | 2023 |
| Arrow Mile Logistics Ltd | Transport & logistics | 2026 |
| ARS Contractors Ltd | Construction | 2018 |
| Arslan Box Storage Ltd | Transport & logistics | 2026 |
| Arslan Cash & Carry Limited | Other services | 2012 |
| Arslan Holdings Ltd | Real estate | 2024 |
| Arslan Investments Ltd | Real estate | 2021 |
| Arslan Top Shop Ltd | Wholesale & retail | 2025 |
| Arsln Property Limited | Real estate | 2021 |
| Arsov Limited | Construction | 2019 |
| Art 4 Solutions Ltd | Wholesale & retail | 2022 |
| Art Agency Presto Ltd | Education | 2014 |
| Art Decorating Solutions Ltd | Construction | 2021 |
| Arte Pizza Limited | Hospitality | 2016 |
| Artemon Strategy Limited | Professional & scientific | 2022 |
| Arthson Ltd | Transport & logistics | 2019 |
| Arthur C. Heyward Limited | Professional & scientific | 1973 |
| Artisan Restoration Ltd. | Construction | 2015 |
| Artisan Studio London Ltd | Wholesale & retail | 2022 |
| Artraders London Ltd | Other services | 2010 |
| Artwood&Co Ltd | Manufacturing | 2025 |
| Artysansz Ltd | Hospitality | 2025 |
| Arunglen Limited | Real estate | 2023 |
| Arvis Limited | Hospitality | 2011 |
| Arya NYR Ltd | Financial services | 2025 |
| Arya's Boutique Ltd | Wholesale & retail | 2018 |
| Aryan Convenience Stores Ltd | Wholesale & retail | 2019 |
| Aryan Real Estate Investments Limited | Real estate | 2021 |
| Aryana Motors Limited | Wholesale & retail | 2014 |
| Aryasi Limited | Manufacturing | 2025 |
| AS Direct Properties Ltd | Construction | 2019 |
| AS Plumbing & Heating (LDN) Ltd | Construction | 2018 |
| AS Smart Training Limited | Education | 2016 |
| AS1 Investments Ltd | Real estate | 2025 |
| ASA Lodge Ltd. | Health & social care | 2020 |
| Asafo Digital Ltd | Information & communication | 2025 |
| Asaz Ltd | Information & communication | 2013 |
| Ascend Marketing That Matters Ltd | Professional & scientific | 2024 |
| Ascendant Unity Limited | Information & communication | 2025 |
| Ascendclo Ltd | Wholesale & retail | 2025 |
| Ascent Global Holding Ltd | Financial services | 2026 |
| Ascent Global Investment Ltd | Financial services | 2026 |
| Ascent Global Property Ltd | Real estate | 2026 |
| Ascent Solutions Limited | Information & communication | 2025 |
| Ascot Eaton Myers Limited | Real estate | 2021 |
| Ascot Enfield Ltd | Real estate | 2022 |
| Ascot Lodge Freehold Limited | Households | 2014 |
| ASD Advisors Ltd | Administrative & support | 2026 |
| Asel Real Estate Limited | Real estate | 2025 |
| Asen Stanoev Ltd | Manufacturing | 2026 |
| ASG Hair and Beauty Ltd | Other services | 2023 |
| ASH Automotive Limited | Wholesale & retail | 2025 |
| ASH Rehab Ltd | Health & social care | 2021 |
| Ashbeigh Limited | Extraterritorial | 2003 |
| Ashblair Limited | Extraterritorial | 2002 |
| Ashbrook Investments Ltd | Real estate | 2013 |
| Ashby & Tate Limited | Real estate | 2015 |
| Ashdorah Prime Limited | Real estate | 2024 |
| Ashe Tech Solutions Limited | Administrative & support | 2025 |
| Ashford Moore Ltd | Real estate | 2026 |
| Ashgrove RD Ltd | Real estate | 2023 |
| Ashgrove Tax Services Limited | Professional & scientific | 2022 |
| Ashleigh Rose (International) Ltd | Manufacturing | 2003 |
| Ashton House Management Company Limited | Real estate | 2009 |
| Ashtonwell Properties Ltd | Real estate | 2008 |
| Ashurq Limited | Wholesale & retail | 2023 |
| Ashvale Ltd | Extraterritorial | 2005 |
| Asik Mene & Co Ltd | Professional & scientific | 2024 |
| Asim Itech Ltd | Information & communication | 2010 |
| Asir Consulting Services Limited | Information & communication | 2016 |
| ASJ Locksmiths Ltd | Administrative & support | 2025 |
| ASK Carpet & Flooring Ltd | Construction | 2024 |
| ASK Plumbing Ltd | Construction | 2023 |
| Askaa Ltd | Wholesale & retail | 2024 |
| Askew Fish Bar Ltd | Hospitality | 2024 |
| Askin Limited | Hospitality | 2017 |
| Asku Property Limited | Real estate | 2022 |
| Aslan Exclusive Men’S Grooming Ltd | Other services | 2025 |