| ADM Prime Properties Ltd | Real estate | 2025 |
| Aero Carbon Limited | Wholesale & retail | 2021 |
| Aerodyn Ltd | Manufacturing | 2007 |
| Aesra CIC | Professional & scientific | 2019 |
| Affan Food Fusion Ltd | Hospitality | 2024 |
| Afternoomi Ltd | Information & communication | 2025 |
| AG London Consultancy Ltd | Professional & scientific | 2000 |
| AGC Design Limited | Professional & scientific | 2009 |
| Agent Building Services Ltd | Construction | 2019 |
| Agentic-Gtm Ltd | Wholesale & retail | 2025 |
| AH5 Limited | Real estate | 2022 |
| AH6 Limited | Real estate | 2022 |
| AH7 Ltd | Real estate | 2023 |
| Aires DEL SUR Limited | Professional & scientific | 2024 |
| Airon Switch Services Ltd | Information & communication | 2009 |
| Aita Consulting Limited | Information & communication | 2021 |
| Aitken Macdonald Ltd | Professional & scientific | 2026 |
| Aizzon Ltd | Wholesale & retail | 2025 |
| Ajar Consulting Limited | Information & communication | 2016 |
| AJC Advisory Ltd | Professional & scientific | 2024 |
| Ajgraniteuk Limited | Construction | 2013 |
| Ajsportsuk Ltd | Wholesale & retail | 2021 |
| Akanni Estates Limited | Real estate | 2019 |
| Akash Properties Investment Ltd | Real estate | 2016 |
| Akgun Restaurant Limited | Hospitality | 2019 |
| Akhm Ltd | Hospitality | 2020 |
| Akhm Properties Ltd | Real estate | 2025 |
| Akilah Aesthetics Ltd | Health & social care | 2023 |
| Aknk Properties Ltd | Real estate | 2019 |
| Akvosphere UK Ltd | Water & waste | 2023 |
| AL Design Studio Ltd | Information & communication | 2024 |
| Alanmo Consultancy Limited | Professional & scientific | 2015 |
| ALARM7 Fire & Security Ltd | Administrative & support | 2022 |
| ALBO49 Limited | Professional & scientific | 2023 |
| Alexyon Ltd | Construction | 2014 |
| Alfa Investmens Limited | Real estate | 2021 |
| ALI Ecom Solutions Limited | Wholesale & retail | 2025 |
| Alimin Properties Limited | Construction | 2019 |
| ALL by Asia Ltd | Real estate | 2020 |
| Allbikes (Surrey) Limited | Wholesale & retail | 2012 |
| Allied Building Contractors Limited | Construction | 2000 |
| Allium House RTM Company Limited | Households | 2024 |
| Allure Luxe Ltd | Other services | 2022 |
| Almanzora Properties Limited | Real estate | 2006 |
| Alphex Tech Ltd | Information & communication | 2026 |
| Always Learning More Ltd | Education | 2025 |
| Amanat Investments Limited | Real estate | 2002 |
| Amandeep Kalra Architects Ltd | Professional & scientific | 2018 |
| Amarachi Consulting Ltd | Hospitality | 2023 |
| Ambuyat Consulting Ltd | Professional & scientific | 2022 |
| Amity (IT) Services Limited | Information & communication | 2010 |
| Amjap Building Servies Limited | Construction | 2026 |
| Ammul Ltd | Education | 2026 |
| Amudha Living Ltd | Wholesale & retail | 2025 |
| Amwari Ltd | Wholesale & retail | 2024 |
| Anand Real Estate Ltd | Real estate | 2022 |
| Andrews House 07 Ltd | Wholesale & retail | 2024 |
| Angels Herald Ltd | Wholesale & retail | 2025 |
| Anitya Commerce Advisory Ltd | Information & communication | 2025 |
| Annams Interiors UK Ltd | Construction | 2013 |
| Anshu Consultancy Limited | Information & communication | 2024 |
| Anshu Investment Management Ltd | Real estate | 2019 |
| Anshu Technology Limited | Information & communication | 2024 |
| Anthony Mundy & Co Ltd | Professional & scientific | 2007 |
| Antmusicprods Ltd | Information & communication | 2026 |
| Antro Freehold Group Limited | Households | 2024 |
| Apex Collection Ltd | Wholesale & retail | 2025 |
| Appendigital Ltd | Information & communication | 2019 |
| Appex Technicians Ltd | Professional & scientific | 2022 |
| Applehouse Properties Limited | Real estate | 2003 |
| Appollo Bird Consultants Ltd | Professional & scientific | 2014 |
| Aptus Software Labs Europe Ltd | Information & communication | 2009 |
| AR Holdings Investments Ltd | Financial services | 2025 |
| ARA Business Consulting Limited | Information & communication | 2015 |
| Araa Ltd | Real estate | 2020 |
| Arabel Medical Ltd | Health & social care | 2026 |
| Arabic Online Ltd | Education | 2018 |
| Araucaria Services Limited | Real estate | 2023 |
| Archinteriors Ltd. | Construction | 2013 |
| Arcticzymes UK Ltd | Professional & scientific | 2026 |
| Argus Directors Limited | Professional & scientific | 2010 |
| Aria Group Limited | Financial services | 2015 |
| Aris Homes Limited | Real estate | 2016 |
| Arjen Ltd | Real estate | 2022 |
| ARM Pizza Ltd | Hospitality | 2023 |
| Armadillo Training Ltd | Health & social care | 2003 |
| Aromatic Thali Ltd | Hospitality | 2019 |
| ARP Infotech Ltd | Information & communication | 2026 |
| Arran and Darran Enterprises Ltd | Real estate | 2019 |
| Arran and Darran Ltd | Health & social care | 2018 |
| Arrivli Ltd | Information & communication | 2026 |
| Arruba Ltd | Wholesale & retail | 2011 |
| Arrys Limited | Information & communication | 2022 |
| Artebene Limited | Administrative & support | 2007 |
| Artemis Insurance Brokers Ltd. | Financial services | 2010 |
| Artemis One Ltd | Real estate | 2025 |
| Artisan Cake Limited | Wholesale & retail | 2023 |
| Artrah Ltd | Arts & recreation | 2023 |
| Arttech Inst Ltd | Information & communication | 2020 |
| Aruba (UK) Limited | Wholesale & retail | 2005 |