| Agro Ceylon Limited | Wholesale & retail | 2020 |
| AGS Deelightful Events Ltd | Hospitality | 2020 |
| Agência Zampa Supremo Ltd | Professional & scientific | 2025 |
| Aherns Roofing Ltd | Construction | 2026 |
| Ahmad Fast Food Limited | Hospitality | 2022 |
| Ahmed Jewellers Ltd | Wholesale & retail | 2019 |
| Ahote Films Ltd. | Information & communication | 2009 |
| Ahsan Ltd | Hospitality | 2018 |
| AI Data Services Limited | Information & communication | 2025 |
| AIDEN22 Ltd | Health & social care | 2024 |
| AIE Events Ltd | Wholesale & retail | 2025 |
| Aiga Residential Ltd | Real estate | 2016 |
| Aigis Security Consultants Ltd | Professional & scientific | 2002 |
| Aignosis Limited | Health & social care | 2025 |
| Aikon Method Group Ltd | Professional & scientific | 2026 |
| Ailo Limited | Other services | 2024 |
| AIM Driven Solutions Limited | Information & communication | 2012 |
| AIM Healthinfo Consultancy Limited | Professional & scientific | 2015 |
| AIM Play Ltd | Arts & recreation | 2019 |
| Ainhoaethan Ltd | Real estate | 2024 |
| Airbabies Ltd | Wholesale & retail | 2022 |
| Airbash Ltd | Wholesale & retail | 2023 |
| Aires Publishing Ltd | Information & communication | 2021 |
| Airficent (Holding) Ltd | Real estate | 2021 |
| Airficieant Ltd | Wholesale & retail | 2020 |
| Airflow Ventilation Ltd | Administrative & support | 2012 |
| Airgead Investments Ltd | Financial services | 2017 |
| Airmicasa Ltd | Real estate | 2024 |
| Airsucker Ltd | Manufacturing | 2026 |
| AIS Global Ventures Limited | Financial services | 2025 |
| AIS Pensions LLP | | 2015 |
| Aisigint Ltd | Information & communication | 2026 |
| Aitchison Development Construction Ltd | Construction | 2013 |
| Aitron Ltd | Information & communication | 2022 |
| AJ Asset Solutions Limited | Real estate | 2021 |
| AJ Call Ltd | Administrative & support | 2026 |
| AJ Innovative Solutions Ltd | Information & communication | 2024 |
| AJ Sports Limited | Arts & recreation | 2017 |
| AJ Sports Tours Ltd | Administrative & support | 2021 |
| Ajaj Ltd | Professional & scientific | 2017 |
| Ajay Electronics Limited | Manufacturing | 1976 |
| AJB Audio Ltd | Information & communication | 2019 |
| AJC Enterprise Investment Ltd | Real estate | 2017 |
| Ajcap Limited | Real estate | 2010 |
| AJM VK Ltd | Professional & scientific | 2024 |
| AJP Engineers Ltd | Professional & scientific | 2014 |
| Ajwa Enterprises Limited | Wholesale & retail | 2026 |
| AK Thangamaligai Limited | Wholesale & retail | 2024 |
| AKC Europe Ltd. | Construction | 2008 |
| Akcha Traders Ltd | Construction | 2018 |
| Akemid Limited | Wholesale & retail | 2025 |
| AKJ Consultancy Limited | Professional & scientific | 2021 |
| AKL Freehold Limited | Households | 2004 |
| Akodai Ltd | Administrative & support | 2025 |
| Akos Agro Limited | Manufacturing | 2025 |
| Akropolis Ltd | Construction | 2012 |
| Aksharan Foundation | Health & social care | 2018 |
| Akta Consulting Limited | Information & communication | 2015 |
| Akter's Trading Ltd | Wholesale & retail | 2020 |
| AL - Subhan Enterprises Limited | Wholesale & retail | 2025 |
| AL Hamd Halal Meat Sutton Ltd | Wholesale & retail | 2025 |
| AL Noor Cars Limited | Transport & logistics | 2015 |
| Al-Kindi | Other services | 2014 |
| Al-Mubarakia Limited | Real estate | 2009 |
| Alan Barbers Surrey Ltd | Other services | 2022 |
| Alaskan Properties Ltd | Real estate | 2015 |
| Alaskan Windows Ltd | Construction | 2004 |
| Alban Plumbing and Heating Ltd | Construction | 2021 |
| Albert Soden (Holdings) Limited | Real estate | 1991 |
| Albion Court (Sutton SM2) Limited | Households | 2024 |
| Albion Integrated Ltd | Manufacturing | 2025 |
| Albion Management (Sutton) Limited | Households | 2005 |
| Alchemation Limited | Arts & recreation | 2018 |
| Aleem Chowdhry Limited | Information & communication | 2010 |
| Aleem Ltd | Administrative & support | 2016 |
| Aleksandar Pashov Ltd | Transport & logistics | 2024 |
| Alena Events Ltd | Administrative & support | 2019 |
| Alentis Recruitment Ltd | Professional & scientific | 2020 |
| Aletheian Advisors Limited | Financial services | 2019 |
| Alex & Aaron Properties Ltd | Real estate | 2022 |
| Alex Anthony Construction Ltd | Construction | 2017 |
| Alex Construction Services Ltd | Construction | 2019 |
| ALEX06 Ltd | Construction | 2008 |
| Alexander James Design Ltd. | Wholesale & retail | 2013 |
| Alexander Krige Ltd | Arts & recreation | 2025 |
| Alexander Lodge Freehold Company Limited | Households | 2022 |
| Alexandra Road MGT Co Limited | Households | 2024 |
| Alexandrite Innovations Ltd | Information & communication | 2023 |
| Alexandrite Software Ltd | Information & communication | 2022 |
| Alexxus Ltd | Health & social care | 2022 |
| ALI Efendi Ltd | Hospitality | 2024 |
| Alia Homes Southern Limited | Construction | 2022 |
| Alice Haynes Racing Limited | Administrative & support | 2017 |
| Alicia Sophie Limited | Health & social care | 2021 |
| Alin Alpin Ltd | Construction | 2011 |
| Aliosman Ltd | Transport & logistics | 2018 |
| ALL Craft Roofing Ltd | Construction | 2024 |
| ALL Flowers Ltd | Wholesale & retail | 2022 |
| ALL for One Maintenance Ltd | Construction | 2024 |
| ALL in International Services Ltd | Other services | 2022 |