| Arch Property Group Ltd | Real estate | 2022 |
| Arch-Tech Building Design Limited | Professional & scientific | 2009 |
| Archer House Consulting Ltd | Information & communication | 2015 |
| Archi - EG Limited | Construction | 2018 |
| Archway Building Consultancy Limited | Construction | 2017 |
| Archway Capital Ventures Limited | Financial services | 2026 |
| Archway Party Wall Surveyors Ltd | Professional & scientific | 2023 |
| Archway Pizza DA Milano Ltd | Hospitality | 2025 |
| Archway Property Development Ltd | Construction | 2018 |
| Archway Property Ventures Limited | Real estate | 2026 |
| Archway Strategic Holdings Ltd | Financial services | 2026 |
| Archway Techsurv Ltd | Construction | 2023 |
| Archways Pizza DA Milano Ltd | Hospitality | 2026 |
| Arclambda Ltd | Information & communication | 2019 |
| Ard@Agd Ltd | Construction | 2019 |
| Ardentis Innovations Ltd | Professional & scientific | 2025 |
| AREL2021 Ltd | Other services | 2025 |
| Arendse Family Law Limited | Professional & scientific | 2024 |
| Ares A.D. Ltd | Construction | 2021 |
| Aresh Capital Ltd | Financial services | 2024 |
| Arezo Properties Ltd | Real estate | 2025 |
| Arham Solutions Limited | Real estate | 2014 |
| Ari-O Chattels Ltd | Real estate | 2023 |
| Aria Horizons Limited | Manufacturing | 2016 |
| Ariana - Services Limited | Construction | 2016 |
| Ariana First Service Limited | Wholesale & retail | 2013 |
| Ariana Hair Dressing Salon Limited | Other services | 2018 |
| Ariana Hair Stylists Ltd | Other services | 2018 |
| Ariana Hairstylist (Harrow) Ltd | Other services | 2018 |
| Ariana World Wide Ltd | Wholesale & retail | 2012 |
| Aries Timber Exports Limited | Wholesale & retail | 2014 |
| Arigal FS Limited | Financial services | 2014 |
| Arigal Wealth Management Ltd | Professional & scientific | 2009 |
| Arihant Medical Solutions Limited | Health & social care | 2024 |
| Arihant Properties Ltd | Real estate | 2023 |
| Arina Restaurant Ltd | Hospitality | 2025 |
| Arise Asian Limited | Real estate | 2024 |
| Arisen Ltd | Construction | 2025 |
| Arivu Trust UK Ltd | Education | 2022 |
| Arizen Ltd | Real estate | 2025 |
| ARK Edgware Limited | Wholesale & retail | 2019 |
| ARK Sunrise Ltd | Wholesale & retail | 2020 |
| Arkadiya Limited | Real estate | 2021 |
| Arkangel Productions Limited | Information & communication | 2016 |
| Arkansas West Limited | | 2011 |
| Arkin Associates Limited | Professional & scientific | 2008 |
| Arkix Design Ltd | Professional & scientific | 2025 |
| Arklinks Limited | Construction | 1976 |
| Arko Construction Ltd | Construction | 2022 |
| Arks Restaurants Limited | Hospitality | 2021 |
| Arleia Tech Consulting Limited | Professional & scientific | 2026 |
| Arlene's Holdings Limited | Financial services | 2020 |
| Arlene's Properties (London) Limited | Real estate | 2020 |
| Arlyruby Limited | Hospitality | 2019 |
| Arma Investments Limited | Financial services | 2022 |
| Arma LDN Ltd | Wholesale & retail | 2020 |
| Arma Projects Ltd | Construction | 2020 |
| Armaghan (London) Limited | Wholesale & retail | 2024 |
| Arman Cars Ltd | Wholesale & retail | 2019 |
| Armoni Buildings Ltd | Construction | 2025 |
| Armoni Ltd | Real estate | 2025 |
| Arms Engineering Ltd | Construction | 2017 |
| Armstrong Huntley Ltd | Households | 2022 |
| Arni Properties Limited | Real estate | 2019 |
| ARO Painting and Decorating Ltd | Construction | 2023 |
| Arogant Ltd | Wholesale & retail | 2020 |
| Aroma Bakery Ltd | Wholesale & retail | 2025 |
| Arome Atelier Ltd | Manufacturing | 2025 |
| Aronclaudia Ltd | Construction | 2022 |
| Arora Property Investments Limited | Real estate | 2021 |
| ARP Theatre Limited | Arts & recreation | 2016 |
| Arrd Investments Limited | Real estate | 2017 |
| Arrowlight Limited | Real estate | 2016 |
| Arsalan Collection Ltd | Wholesale & retail | 2019 |
| Arsana Limited | Real estate | 2021 |
| Arseniou Neurophysiology Ltd | Health & social care | 2023 |
| Arsinte Construction Limited | Construction | 2017 |
| Art Chauffeur Services Ltd | Transport & logistics | 2011 |
| Artax Capital Ltd | Professional & scientific | 2022 |
| Artemee Advisors Limited | Administrative & support | 2020 |
| Artemis Advisors Limited | Financial services | 2005 |
| Artic Trucking Co.Limited | Administrative & support | 1957 |
| Artilligence Ltd | Extraterritorial | 2013 |
| Artisan Peninsula Ltd | Real estate | 2020 |
| Artist Construction Limited | Construction | 2026 |
| Artistic Clothing Ltd | Wholesale & retail | 2023 |
| Artloe Limited | Manufacturing | 2019 |
| Artocopus Limited | Financial services | 2015 |
| Artus and Truelove Limited | Real estate | 2001 |
| Artwell Properties Limited | Real estate | 2021 |
| Arun Property Investment Holdings Ltd | Real estate | 2025 |
| Aruna Lettings Ltd | Real estate | 2026 |
| Arundel Property Management Ltd | Households | 2019 |
| Arundell Carpets Holdings Limited | Real estate | 1972 |
| Arvo Buildings Ltd | Administrative & support | 2017 |
| Arya Investments Limited | Real estate | 2007 |
| Arya Projects Limited | Construction | 2022 |
| Aryana Fish & Meat Ltd | Wholesale & retail | 2021 |
| Aryash Power Engineers Limited | Construction | 2012 |
| Arytech Limited | Information & communication | 2025 |