| ATELIER777 Ltd | Manufacturing | 2025 |
| Atesoglu Consultancy Ltd | Wholesale & retail | 2020 |
| Athithi Consulting Ltd | Information & communication | 2013 |
| Atlantic Finance Group Ltd | Real estate | 2020 |
| Atri Ltd | Real estate | 2021 |
| Atrubeauty Ltd | Other services | 2024 |
| Atrucafe Ltd | Hospitality | 2024 |
| Atrumedia Ltd | Manufacturing | 2024 |
| Atrupharma Ltd | Wholesale & retail | 2020 |
| Atruproperty Ltd | Real estate | 2019 |
| Attila Kent Ltd | Education | 2024 |
| Aubrey Corporation Ltd | Health & social care | 2014 |
| Augurity Ltd | Information & communication | 2019 |
| Aura Building Supplies Limited | Wholesale & retail | 2020 |
| Auralite Atelier Ltd | Wholesale & retail | 2026 |
| Aureolus Limited | Information & communication | 2013 |
| Aurex Capital Group Ltd | Agriculture & fishing | 2025 |
| Aussie Logistics Limited | Public administration | 2014 |
| Auster Enterprises Limited | Administrative & support | 2025 |
| Authentic YOU NOW Ltd | Other services | 2011 |
| Auto 50 Ltd | Wholesale & retail | 2017 |
| Auto Products Ltd | Wholesale & retail | 2017 |
| Automapath Ltd | Information & communication | 2025 |
| Autoroute Limited | Wholesale & retail | 2022 |
| Autoturn IT Limited | Manufacturing | 2021 |
| Autoworks Systems Limited | Information & communication | 2019 |
| Autumn Sisters Ltd | Other services | 2020 |
| Avalon HR and Training Ltd | Education | 2011 |
| Avatar Retail Ltd | Wholesale & retail | 2018 |
| Avenorservices Ltd | Professional & scientific | 2025 |
| Aventro Ltd | Wholesale & retail | 2025 |
| Avermann England Ltd | Wholesale & retail | 2026 |
| Avery Hill Services Limited | Transport & logistics | 2005 |
| Avesen Ltd | Wholesale & retail | 2018 |
| Avibuy Aircraft and Parts Limited | Other services | 2022 |
| Avid Consulting Ltd | Professional & scientific | 2024 |
| Avid London Ltd | Information & communication | 2019 |
| Avid Roofing and Building Ltd | Construction | 2025 |
| Avighna Tech Solutions Ltd | Information & communication | 2022 |
| Avjp Project Management Ltd | Information & communication | 2019 |
| Avonhead Financial Consultants Limited | Professional & scientific | 2005 |
| AW Commercial Ltd | Wholesale & retail | 2025 |
| Awemazing Ltd | Professional & scientific | 2023 |
| AWS Plastering Limited | Construction | 2006 |
| Axim Build Ltd | Construction | 2012 |
| Axion Construction Ltd | Construction | 2026 |
| Axion Ventures Ltd | Real estate | 2026 |
| Axios Group Ltd | Administrative & support | 2018 |
| Axis Wellness Partners Ltd | Professional & scientific | 2025 |
| Axon Insights Limited | Wholesale & retail | 2024 |
| Axtract Business Solutions Ltd | Wholesale & retail | 2025 |
| Ayam Zaman Ltd | Extraterritorial | 2015 |
| Ayapa Accessories Limited | Wholesale & retail | 2017 |
| Ayapa Properties Ltd | Real estate | 2023 |
| AYB Homes Ltd | Real estate | 2021 |
| AYB Limited | Professional & scientific | 2018 |
| AYB Solutions Limited | Information & communication | 2023 |
| Ayora Ltd | Professional & scientific | 2020 |
| Ayrine & DON Limited | Wholesale & retail | 2022 |
| Ayush Services Ltd | Professional & scientific | 2022 |
| Ayva Capital Limited | Real estate | 2024 |
| Ayyami Co., Ltd | Wholesale & retail | 2022 |
| Ayyash Publishing Ltd | Information & communication | 2023 |
| AZ Pipe Solutions Ltd | Construction | 2024 |
| Azhiya Limited | Information & communication | 2008 |
| B & D Enterprises Ltd | Financial services | 2019 |
| B & K Environmental Services Limited | Other services | 2006 |
| B & R Bistros Ltd | Hospitality | 2019 |
| B E H Laluvein Consulting Limited | Professional & scientific | 2010 |
| B Graduate School Ltd | Education | 2012 |
| B Hive Learning Limited | Information & communication | 2012 |
| B&K Ruislip Yard Ltd | Real estate | 2025 |
| B-Advancy Certification UK Ltd. | Professional & scientific | 2020 |
| B.C.Mistry Limited | Professional & scientific | 2020 |
| B.Uniq Limited | Wholesale & retail | 2018 |
| BAA Investments Limited | Real estate | 2025 |
| Baasher Solutions Limited | Information & communication | 2026 |
| Bacoyo Limited | Wholesale & retail | 2025 |
| Badger Books Limited | Information & communication | 2024 |
| Bailey Creative Ltd | Administrative & support | 2018 |
| Bailey's Lead Works Ltd | Construction | 2023 |
| Bains Driving School Limited | Education | 2022 |
| Baixin Shoes Trading Co., Ltd | Administrative & support | 2023 |
| Bakhishli.Com Ltd | Information & communication | 2024 |
| BAL Singh Limited | Construction | 2019 |
| Balada Group Holdings Limited | Real estate | 2026 |
| Balada Group Ltd | Real estate | 2020 |
| Balance Psych Ltd | Health & social care | 2024 |
| Balancewell Holistic Therapy Ltd | Health & social care | 2021 |
| Baldrik Limited | Construction | 2014 |
| Bally Skips Ltd | Water & waste | 2014 |
| Balsa Ltd | Professional & scientific | 2015 |
| BAN Shamoon Properties Ltd | Real estate | 2021 |
| Banbury (BAS) Limited | Administrative & support | 2015 |
| Bandz Entertainment Ltd | Information & communication | 2025 |
| Banquet Bliss Ltd | Administrative & support | 2025 |
| Banyan FIG Ltd | Information & communication | 2025 |
| Banāvō Ltd | Professional & scientific | 2023 |
| Baork Consultancy & Construction Services Ltd | Construction | 2026 |
| Bar Buddy Ltd | Information & communication | 2025 |