| Arrow Haulage Services Ltd | Transport & logistics | 2023 |
| Arrow Property Ltd | Real estate | 2022 |
| Arrow Support Services Ltd | Administrative & support | 2026 |
| Arrowknee Ltd | Information & communication | 2024 |
| Arshad Ltd | Wholesale & retail | 2024 |
| Arshman Halal Meat Ltd | Wholesale & retail | 2025 |
| Arsiiah's Luxe Limited | Wholesale & retail | 2026 |
| Arslan Massage & Therapy Ltd | Health & social care | 2021 |
| Art 86 Limited | Financial services | 2019 |
| Art and I Limited | Arts & recreation | 2022 |
| Art by Caroline Boff Ltd | Wholesale & retail | 2022 |
| Art Courier Limited | Transport & logistics | 2021 |
| Art for YOU C.I.C. | Arts & recreation | 2012 |
| Art of Radical Limited | Wholesale & retail | 2024 |
| Art of Stylez Ltd | Wholesale & retail | 2025 |
| Art Tech IT Ltd | Information & communication | 2019 |
| ARTBURST21 Ltd | Arts & recreation | 2015 |
| Artem Recruitment Ltd | Administrative & support | 2016 |
| Artemis Consulting Services Limited | Professional & scientific | 2024 |
| Artemis Trade Solutions Ltd | Wholesale & retail | 2024 |
| Artez Group Limited | Professional & scientific | 2013 |
| Arthur Holdings (Horwich) Ltd | Real estate | 2023 |
| Arthurian Marketing Ltd | Professional & scientific | 2020 |
| Artifex NW Ltd | Construction | 2021 |
| Artificial Intelligence Engineers Ltd | Wholesale & retail | 2024 |
| Artisan DRY Lining Ltd | Construction | 2017 |
| Artisan Emporium Ltd | Wholesale & retail | 2024 |
| Artisan Furnishings Limited | Manufacturing | 2007 |
| Arucal Ltd | Wholesale & retail | 2019 |
| Arvarsani Properties Ltd | Real estate | 2025 |
| Arvind Naran Vala Indira Aastha Properties Ltd | Administrative & support | 2024 |
| Arwa Collection Limited | Wholesale & retail | 2025 |
| Arxality Limited | Wholesale & retail | 2023 |
| Arxenix Ltd | Extraterritorial | 2015 |
| Arya Autos Ltd | Other services | 2018 |
| Aryana Food Distribution Limited | Wholesale & retail | 2022 |
| Aryo Properties Ltd | Real estate | 2022 |
| ARZ Haulage NW Ltd | Transport & logistics | 2025 |
| ARZ Services Limited | Transport & logistics | 2022 |
| Arza Bioscience Limited | Professional & scientific | 2017 |
| Arzoid Ltd | Wholesale & retail | 2022 |
| AS Properties Group Ltd | Real estate | 2021 |
| AS Ecom Trading Ltd | Wholesale & retail | 2025 |
| AS Real Estate Trading Limited | Real estate | 2025 |
| AS Required Limited | Professional & scientific | 2010 |
| AS Siddeeq Holdings Limited | Financial services | 2024 |
| AS Smile Care Ltd | Health & social care | 2024 |
| AS Vitality UK Ltd | Wholesale & retail | 2024 |
| AS WE ARE Ltd | Wholesale & retail | 2025 |
| AS Xcel Ltd | Hospitality | 2025 |
| As-Ms Accountants Limited | Professional & scientific | 2023 |
| ASA Real Estate Management Ltd | Real estate | 2025 |
| Asad Movers Ltd | Transport & logistics | 2025 |
| Asap Transport Service Limited | Other services | 2018 |
| Asari Solutions Ltd | Information & communication | 2021 |
| Asas Convenience Ltd | Wholesale & retail | 2025 |
| Asas Developments Ltd | Real estate | 2018 |
| ASB Media Investment Group Limited | Information & communication | 2022 |
| ASB Trading Ltd | Transport & logistics | 2011 |
| ASC (Steeplejacks) Ltd | Construction | 2017 |
| ASC Capital Investments Ltd | Financial services | 2024 |
| ASC Healthcare Limited | Health & social care | 2013 |
| ASC UK Properties Ltd | Households | 2024 |
| Ascalon Properties Limited | Real estate | 2013 |
| Ascend Investors Ltd | Real estate | 2026 |
| Ascend T&T Ltd | Real estate | 2025 |
| Ascend Wellbeing Limited | Health & social care | 2026 |
| Ascendo Partners Limited | Professional & scientific | 2024 |
| Ascent Cars Ltd | Wholesale & retail | 2013 |
| Ascent Imports Ltd | Wholesale & retail | 2025 |
| Ascent Retail Ltd | Wholesale & retail | 2019 |
| Ascento Limited | Wholesale & retail | 2014 |
| Ascorium Limited | Wholesale & retail | 2023 |
| Ascot College Limited | Education | 2013 |
| Ascot Holdings Limited | Real estate | 2016 |
| Ascot Homes (D’Urton) Limited | Construction | 2017 |
| Aseel C. E. Ltd | Professional & scientific | 2021 |
| Aseel Commercial Management Ltd | Construction | 2025 |
| Asenmo Ltd | Professional & scientific | 2025 |
| ASH Marques Limited | Wholesale & retail | 1999 |
| ASH Medical Solutions Ltd | Health & social care | 2022 |
| ASH Motor Parts Ltd | Wholesale & retail | 2025 |
| ASH R Management Ltd | Households | 2025 |
| ASH UK Properties Ltd | Real estate | 2024 |
| Ashbee Ltd | Wholesale & retail | 2022 |
| Ashbury Fields Properties and Developments Limited | Real estate | 2026 |
| Ashcroft House (Monton) Limited | Construction | 2022 |
| Ashcroft Plant (Cumbria) Limited | Construction | 1999 |
| Ashcroft Trading Ltd | Wholesale & retail | 2026 |
| Ashdale Construction Ltd | Construction | 2010 |
| Ashdale Property Services Limited | Administrative & support | 2015 |
| Ashe Autos & Tyres Ltd | Wholesale & retail | 2024 |
| Asher Ventures Limited | Financial services | 2025 |
| Ashfield (UK) Limited | Manufacturing | 1986 |
| Ashfield Accountants Ltd | Professional & scientific | 2021 |
| Ashfield Enterprise Ltd | Financial services | 2009 |
| Ashland Wealth Management Limited | Professional & scientific | 2016 |
| Ashley & Arlo Properties Ltd | Real estate | 2025 |
| Ashley Jackson Manchester Ltd | Construction | 2015 |
| Ashley Property Solutions Ltd | Households | 2025 |