| Asim Motors Ltd | Wholesale & retail | 2026 |
| Askk Technologies Ltd | Administrative & support | 2016 |
| Asko Foods Limited | Manufacturing | 2013 |
| Asko Holdings Ltd | Financial services | 2026 |
| Asko Investment Ltd | Real estate | 2023 |
| Asko Supermarket Ltd | Wholesale & retail | 2024 |
| ASL London East Ltd | Real estate | 2020 |
| Aslan Sani Ltd | Wholesale & retail | 2025 |
| Asleen Online Ltd | Education | 2021 |
| Aspire & Achieve Group Limited | Education | 2025 |
| Aspire Action CIC | Education | 2025 |
| Aspire Excel Ltd | Administrative & support | 2016 |
| Aspire Holidays Ltd | Administrative & support | 2022 |
| ASR Trading Limited | Wholesale & retail | 2016 |
| Asset Acquisitions (UK) Limited | Real estate | 2004 |
| Asset Domain Limited | Real estate | 2007 |
| Assimulate Consultancy Ltd | Professional & scientific | 2018 |
| Assist Accountants Limited | Professional & scientific | 2020 |
| Assistant Management Group London Ltd | Construction | 2017 |
| Assos & Partners UK Limited | Wholesale & retail | 2019 |
| Assured Compliance Limited | Professional & scientific | 2025 |
| Assured Team Ltd | Transport & logistics | 2022 |
| Aster Support Services Ltd | Health & social care | 2024 |
| Astra Enterprises Limited | Real estate | 2017 |
| Astral Consultancy Ltd | Construction | 2024 |
| Asun Real Estate Ltd | Real estate | 2023 |
| AT & SM London Limited | Real estate | 2025 |
| ATB Records Limited | Information & communication | 2024 |
| Atektas Group Limited | Real estate | 2025 |
| Atelia Nails Ltd | Other services | 2025 |
| Atency Services Ltd | Real estate | 2006 |
| ATF Operators Association Limited by Guarantee Limited | Transport & logistics | 2017 |
| Atkinson Contract Services Limited | Other services | 1990 |
| Atkinson Morley Limited | Other services | 2017 |
| Atlantic Fish (UK) Limited | Hospitality | 2014 |
| Atlantis Infotech Ltd | Information & communication | 2020 |
| Atlantis Travel & Tours Ltd | Transport & logistics | 2025 |
| Atlantizenith Unipessoal Build Master Limited | Construction | 2023 |
| Atlantizenith Unipessoal Ltd | Health & social care | 2020 |
| Atlas Flow Cargo Ltd | Transport & logistics | 2026 |
| Atlas General Property Services Ltd | Construction | 2026 |
| Atlas Plumbing & Drainage Co Ltd | Water & waste | 2016 |
| Atlas Secure Services Ltd | Administrative & support | 2025 |
| Atms Interiors Ltd | Construction | 2025 |
| Attri Consultancy Ltd | Professional & scientific | 2025 |
| Atvantic Ltd | Transport & logistics | 2020 |
| AU Systems Limited | Information & communication | 2017 |
| Audentes Fortuna Ltd | Administrative & support | 2025 |
| Auditax Financial Ltd | Wholesale & retail | 2020 |
| AUF Educational Services Ltd | Education | 2024 |
| Augustas Trading Ltd | Administrative & support | 2025 |
| Aura Print Connect Limited | Manufacturing | 2025 |
| Auran Motor Company Ltd | Wholesale & retail | 2017 |
| Aurea CHY Ltd | Real estate | 2025 |
| Aurelie Gadwell Studios Ltd | Information & communication | 2024 |
| Auroraaid Ltd | Health & social care | 2023 |
| Aurum Global Markets Ltd | Education | 2025 |
| Austin Maritime UK Ltd | Professional & scientific | 2009 |
| Auterra Ltd | Construction | 2025 |
| Auto Arsenal Ltd | Wholesale & retail | 2020 |
| Auto Elite London Ltd | Construction | 2019 |
| Auto Passive Income Ltd | Wholesale & retail | 2022 |
| Autofix Spares Limited | Wholesale & retail | 2016 |
| Autohubb Ltd | Wholesale & retail | 2019 |
| Autokod Limited | Wholesale & retail | 2026 |
| Autolinkx Limited | Wholesale & retail | 2026 |
| Automann Resources Limited | Hospitality | 2024 |
| Autotorque Garage Ltd | Wholesale & retail | 2020 |
| Autovista Motors Ltd | Wholesale & retail | 2025 |
| Autowow UK Ltd | Wholesale & retail | 2022 |
| AV London Ltd | Construction | 2014 |
| AV2 Entertainment Ltd | Information & communication | 2016 |
| Avalonfix Ltd | Construction | 2024 |
| Avason Property Limited | Real estate | 2024 |
| Avenir Group Limited | Administrative & support | 2017 |
| Avenlabs Limited | Wholesale & retail | 2026 |
| Aventus MAN & Van Removals Limited | Transport & logistics | 2026 |
| Avicenna Medics Ltd | Health & social care | 2014 |
| Avizone UK Ltd | Transport & logistics | 2022 |
| Avon Spey Ltd | Administrative & support | 2018 |
| AW Homes London Limited | Real estate | 2023 |
| Award Creative Solutions Ltd | Arts & recreation | 2025 |
| AWI E-Commerce Ltd | Wholesale & retail | 2026 |
| AWL Haulage Limited | Transport & logistics | 2025 |
| Awlees Divine Ltd | Wholesale & retail | 2025 |
| AWS Clearance Limited | Wholesale & retail | 2026 |
| Axel Education International Limited | Administrative & support | 2024 |
| Axis Logistics Solutions Ltd | Transport & logistics | 2026 |
| Axis Recruitment Group Ltd | Administrative & support | 2025 |
| AY Vision Ltd | Health & social care | 2022 |
| Ayan Autos UK Ltd | Wholesale & retail | 2015 |
| Ayazteamvs Limited | Information & communication | 2026 |
| Ayesh Consultancy Limited | Professional & scientific | 2012 |
| Ayesha Siddiqa Ltd | Professional & scientific | 2022 |
| Aylesford Plastering & Decorating (UK) Co Ltd | Construction | 2016 |
| AYN 02-7 Protection Ltd | Construction | 2026 |
| Aynglobal Limited | Hospitality | 2026 |
| Ayokunmi Limited | Health & social care | 2021 |
| Ayrosys Limited | Information & communication | 2025 |
| Aysha Assets Limited | Real estate | 2021 |