| Arthur Cambrey Limited | Extraterritorial | 2005 |
| Arthur Gresty Limited | Extraterritorial | 1963 |
| Arthur Johnson & Sons Limited | Professional & scientific | 1980 |
| Arthur Street Management 2012 Limited | Households | 2012 |
| Arti & Pari Trading Limited | Wholesale & retail | 2025 |
| Artibus Limited | Education | 2016 |
| Articulate Advantage Limited | Administrative & support | 2023 |
| Artifex Works Limited | Manufacturing | 2020 |
| Artificer Productions Limited | Information & communication | 2017 |
| Artificial Intelligence Academy International Ltd | Education | 2025 |
| Artificii Ltd | Professional & scientific | 2025 |
| Artify Ltd | Wholesale & retail | 2025 |
| Artim Labs Ltd | Information & communication | 2026 |
| Artisan & Colours Limited | Construction | 2026 |
| Artisan AI Limited | Financial services | 2026 |
| Artistic Touch Ltd | Other services | 2024 |
| Artistic Upholstery Holdings Limited | Real estate | 2019 |
| Artistic Upholstery Limited | Manufacturing | 1949 |
| Arto Living Limited | Real estate | 2025 |
| Artoria Ltd | Wholesale & retail | 2026 |
| Artpin Limited | Construction | 2018 |
| Artuk Film Limited | Information & communication | 2017 |
| Artur Turonek Ltd | Transport & logistics | 2011 |
| Artur Wysocki Ltd | Transport & logistics | 2024 |
| Artura Care Group Limited | Other services | 2025 |
| Artura Pharma Holdings Ltd | Financial services | 2025 |
| Arun & Karan Holdings Ltd | Hospitality | 2024 |
| Arun Financial Services Ltd | Financial services | 2021 |
| Arun Kumar Consulting Ltd | Professional & scientific | 2025 |
| Arundel House Residents Association Limited | Real estate | 1986 |
| Arven Group Ltd | Wholesale & retail | 2026 |
| Arvexis Limited | Information & communication | 2026 |
| Arya Cleaning Ltd | Administrative & support | 2020 |
| Arya Supplies Limited | Wholesale & retail | 2018 |
| Aryaass Properties Ltd | Real estate | 2023 |
| Aryal Brothers Gurkha Limited | Hospitality | 2021 |
| Aryan & Anika Properties Ltd | Real estate | 2019 |
| Aryan Solutions Ltd | Administrative & support | 2018 |
| Aryana Cargo Ltd | Transport & logistics | 2026 |
| Aryvhi Care Ltd | Health & social care | 2023 |
| Arzang International Limited | Professional & scientific | 2016 |
| Arzu Properties Ltd | Real estate | 2019 |
| Arzuno Ltd | Wholesale & retail | 2025 |
| AS & JS Solutions Ltd | Professional & scientific | 2025 |
| AS & TT Contracts Ltd. | Construction | 2018 |
| AS Boyal Ltd | Health & social care | 2018 |
| AS Builders (Nottingham) Limited | Construction | 2017 |
| AS Building & Driveways Ltd | Construction | 2023 |
| AS Compliance Limited | Professional & scientific | 2024 |
| AS Consulting & Business Services Ltd | Administrative & support | 2022 |
| AS Consulting & Finance Ltd | Professional & scientific | 2025 |
| AS Contracting UK Limited | Financial services | 2013 |
| AS Film, TV & Media Services Limited | Information & communication | 2017 |
| AS Furniture & Carpets Limited | Wholesale & retail | 2025 |
| AS Maintenance Limited | Other services | 2022 |
| AS Mallick Ltd | Financial services | 2025 |
| AS Move Ltd | Transport & logistics | 2021 |
| AS Moyo Limited | Health & social care | 2013 |
| AS One Builders Limited | Construction | 2019 |
| AS Pharma Consulting Ltd | Administrative & support | 2024 |
| AS Plaice Ltd | Hospitality | 2026 |
| AS Practice Limited | Health & social care | 2014 |
| AS Welder Ltd | Wholesale & retail | 2025 |
| As-Siraat Organisation Ltd | Education | 2023 |
| AS4 Waterproofing Ltd | Construction | 2023 |
| ASA (Nottingham) Limited | Real estate | 2024 |
| ASA Consultation Ltd | Professional & scientific | 2025 |
| ASA Landscaping Limited | Construction | 2021 |
| ASA Sales Limited | Wholesale & retail | 2014 |
| Asad & Sons Property Ltd | Real estate | 2024 |
| Asah Engineering Limited | Construction | 2022 |
| Asah Property Developments Ltd | Construction | 2025 |
| Asam Property Ltd | Construction | 2023 |
| Asamin Properties Limited | Real estate | 2022 |
| Asantey Ltd | Other services | 2023 |
| Asap Appliance Repairs Ltd | Other services | 2024 |
| Asap Corporation Limited | Professional & scientific | 1999 |
| Asap Domestic Repairs Ltd | Other services | 2025 |
| Asap Mobile Battery Service Ltd | Manufacturing | 2021 |
| Asap Roofing and Property Services Ltd | Construction | 2026 |
| Asap Transport Logistics Ltd | Transport & logistics | 2020 |
| Asasco Limited | Health & social care | 2020 |
| Asawla Estates Ltd | Real estate | 2022 |
| ASB Baglung Limited | Hospitality | 2025 |
| ASC Construct Limited | Construction | 2025 |
| ASC Project Solutions Limited | Information & communication | 2025 |
| Ascend Ecommerce Limited | Wholesale & retail | 2026 |
| Ascend ERP Ltd | Information & communication | 2024 |
| Ascend Management Ltd | Households | 2024 |
| Ascendis Ltd | Real estate | 2025 |
| Ascension Media Group Ltd | Information & communication | 2026 |
| Ascension Property Developments Limited | Real estate | 2017 |
| Ascent Property Developments 2 Ltd | Real estate | 2020 |
| Ascent Property Developments Limited | Real estate | 2016 |
| Ascesa Limited | Information & communication | 2009 |
| Asclepius Limited | Administrative & support | 2014 |
| Ascol Limited | Extraterritorial | 2000 |
| Ascot Housing CIC | Real estate | 2024 |
| Ascotmed Limited | Health & social care | 2011 |
| Ascott Stone Limited | Real estate | 2026 |