| Arcadiam Limited | Professional & scientific | 2009 |
| Arcessum Limited | Information & communication | 2017 |
| Archel Road Management Company Limited | Professional & scientific | 2004 |
| Archeus Estate Ltd | Real estate | 2024 |
| Archeus Property Limited | Real estate | 2024 |
| Archinno Ltd | Professional & scientific | 2011 |
| Architecture Factory Limited | Wholesale & retail | 2013 |
| Architiq Group Limited | Professional & scientific | 2020 |
| Archmate Solutions Limited | Information & communication | 2014 |
| Archnest Constructions Ltd | Construction | 2025 |
| Arcus 62 Ltd | Professional & scientific | 2016 |
| Ardent Developers Ltd | Real estate | 2014 |
| Ardent Maritime UK Limited | Construction | 1996 |
| Ardmay Estate Limited | Households | 1985 |
| Arelex Consultancy Ltd | Professional & scientific | 2012 |
| Arena Foods Market Limited | Wholesale & retail | 2024 |
| Ares Holdings International Ltd | Construction | 2026 |
| Arghya Ltd | Information & communication | 2017 |
| Ariella Agyeman Limited | Health & social care | 2021 |
| Arif Kara Investments Limited | Real estate | 2025 |
| Arigatou Ltd | Extraterritorial | 2023 |
| Arihant Technologies Limited | Information & communication | 2022 |
| Arise Children's Home Limited | Health & social care | 2024 |
| Arise Homecare Solutions Ltd | Health & social care | 2017 |
| Arivan Ltd | Education | 2026 |
| Arizata 2001 Ltd | Construction | 2024 |
| Arka Capital Ltd | Information & communication | 2019 |
| Arkizon Investments Ltd | Real estate | 2019 |
| Arkmar Ltd | Wholesale & retail | 2017 |
| Arks Property Management Limited | Households | 2014 |
| Arland Projects Ltd | Real estate | 2026 |
| Arlesiana Ltd | Professional & scientific | 2016 |
| Arlis & Adis Construction Ltd | Construction | 2023 |
| ARM Code Ltd | Information & communication | 2025 |
| Arma GM Limited | Agriculture & fishing | 2018 |
| Armada House Securities Limited | Other services | 1992 |
| Armata Home Limited | Construction | 2014 |
| Armdoc Limited | Health & social care | 2015 |
| Armirate Education Limited | Education | 2023 |
| Armour Consultants Ltd | Administrative & support | 2020 |
| Armour Properties Ltd | Real estate | 2020 |
| Arnica Telecom Ltd | Information & communication | 2014 |
| Arnosh Ltd | Real estate | 2024 |
| Aromma Ltd | Hospitality | 2013 |
| Aronova Holdings Limited | Professional & scientific | 2003 |
| Aronova Interactive Limited | Information & communication | 2003 |
| Arons Construction UK Ltd | Construction | 2016 |
| ARS 84 Limited | Wholesale & retail | 2026 |
| ARS 84 Property Limited | Real estate | 2026 |
| Arsalan Distributions Limited | Transport & logistics | 2025 |
| Artemis Talent Group Limited | Administrative & support | 2020 |
| Arthika Ltd | Real estate | 2026 |
| Artifloor Ltd | Wholesale & retail | 2017 |
| Artizan Brickwork Limited | Construction | 2024 |
| Artmoor House Limited | Arts & recreation | 2010 |
| Arton Screen Ltd | Information & communication | 2016 |
| Aruc Property Ltd | Real estate | 2020 |
| Arun Consultants Ltd | Information & communication | 2015 |
| Arundel Crescent Ltd | Professional & scientific | 2020 |
| Arundel House South Croydon (Freehold) Limited | Households | 2001 |
| Arwin Supermarket Ltd | Wholesale & retail | 2016 |
| Arxnovo Limited | Professional & scientific | 2025 |
| Arya Advani Properties Ltd | Real estate | 2022 |
| Aryaan Grill Ltd | Hospitality | 2019 |
| Arzath Ltd | Manufacturing | 2024 |
| AS Nofil Limited | Education | 2018 |
| AS Service Ltd | Professional & scientific | 2022 |
| Asad & Rizwan Trading Ltd | Wholesale & retail | 2026 |
| Asaitec Ltd | Other services | 2015 |
| ASB Services Electrical & Building Limited | Manufacturing | 2011 |
| Ascend House Limited | Real estate | 2026 |
| ASD Builders Limited | Construction | 1995 |
| ASD Impex Limited | Professional & scientific | 2013 |
| Asfcas Limited | Information & communication | 2025 |
| ASH and SO Ltd | Construction | 2017 |
| ASH Cars (PVT) Ltd | Transport & logistics | 2023 |
| ASH Cars Ltd | Wholesale & retail | 2023 |
| ASH Graham Limited | Real estate | 2003 |
| ASH Transport (Surrey) Ltd | Transport & logistics | 2011 |
| Asharaj Properties Ltd | Real estate | 2025 |
| Ashbourne Capital Estates Limited | Real estate | 2026 |
| Ashdown Freehold (Sutton) Limited | Households | 2015 |
| Ashdown Management Company Limited | Households | 1988 |
| Ashford Builders Limited | | 1979 |
| Ashiana Inc Ltd | Real estate | 2020 |
| Ashiyana Properties PVT Ltd | Real estate | 2015 |
| Ashlei Associates Limited | Information & communication | 2001 |
| Ashwell Landscapes Limited | Administrative & support | 2010 |
| Asma Technologies Ltd | Information & communication | 2025 |
| Asmi Holidays Limited | Administrative & support | 2022 |
| Asomasegaran Ltd | Other services | 2020 |
| Aspc Consultancy Ltd | Health & social care | 2021 |
| Aspect Sales and Lettings Limited | Real estate | 2008 |
| Aspen Capital Partners (Europe) Ltd. | Financial services | 1997 |
| Aspire Educate Ltd | Education | 2019 |
| Aspire Legal Limited | Professional & scientific | 2018 |
| Aspire Meadows Children’S Home Ltd | Health & social care | 2025 |
| Aspire Web Media Limited | Information & communication | 2009 |
| Aspirea Ltd | Information & communication | 2024 |
| Asquare Resources Limited | Real estate | 2025 |