| Asparagus Green Outside Limited | Hospitality | 2019 |
| Aspect Flooring Solutions Ltd | Construction | 2020 |
| Aspect IT Limited | Information & communication | 2003 |
| Aspect Management Group Limited | Financial services | 2023 |
| Aspen Woodwork Limited | Construction | 1995 |
| Aspenwood Finance Ltd | Financial services | 2024 |
| Asphalt Black Ltd | Wholesale & retail | 2021 |
| Aspire (Mboro) Ltd | Other services | 2022 |
| Aspire Aesthetic Academy Ltd | Education | 2021 |
| Aspire Building Solutions Ltd | Construction | 2025 |
| Aspire Care Consultants Ltd | Professional & scientific | 2023 |
| Aspire Construction Projects Ltd | Construction | 2010 |
| Aspire Group 360 Ltd | Manufacturing | 2013 |
| Aspire Hair Studio by Rohan Ltd | Other services | 2024 |
| Aspire Service and Supplies Ltd | Administrative & support | 2013 |
| Aspirecarehomes Ltd | Administrative & support | 2025 |
| Aspirica Ltd | Information & communication | 2020 |
| Asquith Tutoring Ltd | Education | 2022 |
| ASR Optical Services Ltd | Health & social care | 2017 |
| Asset Haven Ltd | Real estate | 2024 |
| Asset Property Ltd | Real estate | 2018 |
| Assist Commercial Ltd | Real estate | 2020 |
| Assistlink Limited | Construction | 1992 |
| Associated North West Media Ltd | Information & communication | 2021 |
| Assp Ltd | Manufacturing | 2019 |
| Assurance Trading Limited | Wholesale & retail | 2014 |
| Assure Certification Ltd | Administrative & support | 2017 |
| Assure Corporate Holdings Ltd | Financial services | 2024 |
| Assure Insolvency Ltd | Financial services | 2025 |
| Assure Property & Estates Ltd | Real estate | 2023 |
| Assure Training Ltd | Education | 2017 |
| Assured GAS Services Limited | Construction | 2013 |
| Assured Passive Fire Inspections Ltd | Construction | 2017 |
| Astade Limited | Construction | 2015 |
| Astbury Contractors Ltd | Construction | 2007 |
| Astell Services Ltd | Administrative & support | 2025 |
| Astirvant Limited | Other services | 1971 |
| Asus RE Ltd | Real estate | 2024 |
| Aswad Enterprises Ltd | Wholesale & retail | 2026 |
| AT Consultancy Group Limited | Professional & scientific | 2026 |
| AT the Lake Limited | Extraterritorial | 2022 |
| At&T Transport Ltd | Transport & logistics | 2021 |
| Atalanti Eight Limited | Real estate | 2005 |
| Atat Group Ltd | Administrative & support | 2023 |
| Atex Electrical Contracting Ltd | Construction | 2024 |
| ATG (N/W) Limited | Construction | 2006 |
| Athbeauty Ltd | Wholesale & retail | 2024 |
| Athena BI Ltd | Administrative & support | 2013 |
| Athene Environmental | Professional & scientific | 2010 |
| Atherton Developments Limited | Real estate | 2020 |
| Athora Aesthetics Limited | Other services | 2026 |
| Athroughz Ltd | Wholesale & retail | 2020 |
| Athy Ltd | Real estate | 2024 |
| Atique Hussain Transport Ltd | Transport & logistics | 2025 |
| Atix Group Company Limited | Wholesale & retail | 2025 |
| Atlantic Publishings Limited | Information & communication | 2024 |
| Atlas Machinery Limited | Wholesale & retail | 2014 |
| Atlas Maintenance Ltd | Other services | 2014 |
| Atlas Trading Business Ltd | Construction | 2007 |
| Atlas Trading Services Ltd | Construction | 2019 |
| Atlas Tube Bending 1 Ltd | Financial services | 2024 |
| Atlas Tube Bending Limited | Manufacturing | 1996 |
| Atlas Tube Holdings Limited | Professional & scientific | 2012 |
| Atlasx Engineering Services Ltd | Manufacturing | 2026 |
| Atomic Buns Ltd | Hospitality | 2025 |
| ATOZ2025 Ltd | Wholesale & retail | 2025 |
| ATP Tuning and Developments Ltd | Wholesale & retail | 2025 |
| ATT Logistics Ltd | Transport & logistics | 2025 |
| Atta Optom Ltd | Health & social care | 2023 |
| Attendant Property Group Ltd | Real estate | 2022 |
| Attentive Deliver Limited | Transport & logistics | 2025 |
| Attia Properties Limited | Real estate | 2002 |
| Attock Properties Limited | Real estate | 2023 |
| Attocks Superstore Limited | Wholesale & retail | 2025 |
| Atws Logistics Consultancy Limited | Transport & logistics | 2013 |
| Atx-Dyno Ltd. | Manufacturing | 2015 |
| Atx-Wash Limited | Administrative & support | 2015 |
| AU Bullion’S Ltd | Manufacturing | 2022 |
| AU Locum Ltd | Health & social care | 2019 |
| Audhealth Ltd | Health & social care | 2026 |
| Audiobeat Limited | Arts & recreation | 1989 |
| Audiobeat Touring Ltd | Information & communication | 2022 |
| Audrey Consultant Limited | Information & communication | 2016 |
| Aughton Utilities Ltd | Water & waste | 2023 |
| Aulakh Prime Ltd | Construction | 2026 |
| AUR Healthcare Ltd | Health & social care | 2025 |
| Aura Cafeteria Ltd | Hospitality | 2023 |
| Aura Cafeteria NW Ltd | Hospitality | 2025 |
| Aura Clip-Ins Ltd | Manufacturing | 2026 |
| Aura Digimart Ltd | Professional & scientific | 2025 |
| Aura Motor Group Ltd | Wholesale & retail | 2024 |
| Auracom Ltd | Manufacturing | 2025 |
| Aure Studio Ltd | Professional & scientific | 2026 |
| Aureon AV Ltd | Professional & scientific | 2026 |
| Aurevexa AI Limited | Wholesale & retail | 2025 |
| Aurevica AI Limited | Wholesale & retail | 2025 |
| Aurion Advisory Limited | Wholesale & retail | 2025 |
| Aurora Resin Ltd | Construction | 2022 |
| Aurora Solid Roof's Limited | Extraterritorial | 2019 |
| Aurore Lodges Ltd | Hospitality | 2019 |