| Admiro Ltd | Other services | 2014 |
| Adrah Ltd | Professional & scientific | 2022 |
| Adro Properties Limited | Real estate | 2017 |
| ADT8 Limited | Health & social care | 2026 |
| Advance Mouldings Limited | Manufacturing | 2007 |
| Advance Space Building & Design Limited | Construction | 2019 |
| Advanced Automotive Performance Ltd | Wholesale & retail | 2012 |
| Advanced Blockage Clearance Limited | Other services | 2002 |
| Advanced Property Maintenance (Surrey) Limited | Construction | 2008 |
| Advanta Business Services Holdings Ltd | Financial services | 2022 |
| Advantage Group Europe Limited | Professional & scientific | 2021 |
| Adventure Golf Developments Ltd | Extraterritorial | 2019 |
| Adventures and Wisdom Community CIC | Education | 2024 |
| Adventures and Wisdom Limited | Professional & scientific | 2023 |
| Advice Help Bureau Limited | Administrative & support | 2026 |
| AE Wealth Ltd | Financial services | 2024 |
| Aegis Rail Limited | Administrative & support | 2006 |
| Aekas Limited | Hospitality | 2019 |
| Aeminium Limited | Health & social care | 2026 |
| Aerial Media Services Ltd | Professional & scientific | 2024 |
| Aesthetica LDN Ltd | Other services | 2022 |
| AF Sports Ventures Limited | Arts & recreation | 2026 |
| Affilica Inpractice Software Ltd. | Other services | 1985 |
| Affinity Dental Care Ltd | Health & social care | 2020 |
| Affinity Property Holdings Ltd | Real estate | 2020 |
| Affirmed Collective Limited | Wholesale & retail | 2022 |
| AFK Industries Ltd | Information & communication | 2024 |
| Africa Wild Trails Limited | Arts & recreation | 2010 |
| AG Aesthetics and Skin Ltd | Other services | 2025 |
| Against the Grain Carpentry and Construction Ltd | Construction | 2025 |
| AGC Robertson Ltd | Health & social care | 2020 |
| AGE Concern (Eastbourne Number 2) Limited | Health & social care | 2003 |
| AGE Concern (Eastbourne) Limited | Wholesale & retail | 1999 |
| AGENCY53 Limited | Professional & scientific | 2017 |
| Aggressive Bear Climbing Ltd | Arts & recreation | 2019 |
| Agnes DOS Santos Ltd | Other services | 2016 |
| Agon Systems EOT Limited | Professional & scientific | 2025 |
| Agon Systems Holdings Limited | Financial services | 2014 |
| Agora Eastbourne Limited | Hospitality | 2019 |
| AGS Advisory Limited | Professional & scientific | 2025 |
| AGT Utilities Limited | Construction | 2025 |
| Ahmed Ibrahim Medical Limited | Health & social care | 2018 |
| Aikaizen Limited | Professional & scientific | 2001 |
| Ainscough Associates Limited | Administrative & support | 2009 |
| Ainsworth Aviation Consultancy Ltd | Professional & scientific | 2018 |
| Aione Asbestos Removal Ltd | Construction | 2016 |
| Aione Environmental Services Ltd | Construction | 2020 |
| Aisake Ltd | Professional & scientific | 2014 |
| AJ Acoustics Limited | Professional & scientific | 2020 |
| Aj's Bodyworks Limited | Wholesale & retail | 2019 |
| Ajapa Ltd | Real estate | 2020 |
| Ajgventures Ltd | Hospitality | 2025 |
| AJH Marketing Limited | Professional & scientific | 2013 |
| AJS Dental Limited | Health & social care | 2015 |
| AJS Smiles Limited | Health & social care | 2019 |
| AJT Media Ltd | Professional & scientific | 2015 |
| AJW Roofing Ltd | Construction | 2022 |
| AK Restaurant Ltd | Hospitality | 2017 |
| Akan Healthcare Ltd | Health & social care | 2025 |
| Akehurst Textiles Ltd | Wholesale & retail | 2025 |
| Akhoury Dental Limited | Health & social care | 2015 |
| Aklass Connexions Ltd | Information & communication | 2015 |
| AL Heliani Ltd | Administrative & support | 2010 |
| Al-Hashim Ltd | Health & social care | 2015 |
| Aladdin Middle East (UK) Limited | Professional & scientific | 2018 |
| Alamand Ltd | Health & social care | 2023 |
| Alan Gadd Properties Ltd | Real estate | 2025 |
| Alan Worrall Limited | Health & social care | 2017 |
| Alanddar Limited | Administrative & support | 2023 |
| Alantica Clothing Ltd | Wholesale & retail | 2016 |
| ALB Properties (South East) Ltd | Real estate | 2025 |
| Albany Park Management UK Limited | Households | 2003 |
| Albbros Construction Ltd | Construction | 2024 |
| Albbros Ltd | Construction | 2020 |
| Albert Road PO Limited | Wholesale & retail | 2025 |
| Albion Counselling Ltd | Health & social care | 2025 |
| Albion Education Limited | Education | 2015 |
| Albion Fine Jewellery Limited | Wholesale & retail | 2007 |
| Albion Ltd | Professional & scientific | 2022 |
| Albusia Ltd | Administrative & support | 2024 |
| ALC Builders Limited | Construction | 2024 |
| Alcazar Court Management Company Limited | Households | 1980 |
| Alcedo Ltd | Professional & scientific | 2026 |
| Alchemy Dynamics & Co Ltd | Professional & scientific | 1999 |
| Aldenham Court RTM Company Limited | Households | 2022 |
| Alderwave Consulting Ltd | Real estate | 2026 |
| Aldgate Associates Limited | Construction | 2008 |
| Alesh Care Limited | Health & social care | 2025 |
| Alex Alcock Investments LLP | | 2006 |
| Alex Buckland Photography Ltd | Professional & scientific | 2024 |
| Alexander Khabbazi Ltd | Professional & scientific | 2026 |
| Alexandraarmspub Ltd | Hospitality | 2026 |
| Alexandri Beauty Ltd | Other services | 2024 |
| Alexcafecare Ltd | Health & social care | 2019 |
| Alexparcel.Com Limited | Transport & logistics | 2024 |
| ALF Investments Ltd | Real estate | 2025 |
| Alfred Honney Limited | Real estate | 1961 |
| Alfriston Consulting Limited | Professional & scientific | 2021 |
| ALH Timber Framing Limited | Construction | 2019 |
| ALI Mohammed Associates Ltd | Professional & scientific | 2025 |