| APG 003 Limited | Real estate | 2020 |
| APG Residential 001 Limited | Real estate | 2022 |
| Apka Associates Ltd | Wholesale & retail | 2019 |
| Apka Holdings Limited | Financial services | 2022 |
| Apka Properties Limited | Real estate | 2022 |
| App RMS Ltd | Hospitality | 2025 |
| Apparelweb Ltd | Wholesale & retail | 2025 |
| Appletree Investment Group Limited | Real estate | 2024 |
| Appleyard Services Limited | Information & communication | 2000 |
| Applied Thinking Ltd | Information & communication | 2013 |
| Appywiththat Ltd | Information & communication | 2025 |
| APS Events & Media EOT Limited | Administrative & support | 2022 |
| APS Events & Media Ltd | Information & communication | 2010 |
| APS Ventilation Services Limited | Manufacturing | 2026 |
| AQ Cleaning Ltd | Administrative & support | 2025 |
| Aqtss Limited | Transport & logistics | 2010 |
| Aqualife Limited | Administrative & support | 2025 |
| AR2 Installations Ltd | Construction | 2010 |
| ARA Recruitment Ltd | Administrative & support | 2022 |
| Aram Properties Ltd | Real estate | 2024 |
| Aras Maintenance Ltd | Construction | 2026 |
| ARC Phalanx Security Group Ltd | Administrative & support | 2026 |
| Arch Cafe and Bakery Ltd | Hospitality | 2026 |
| Archchi's Catering Ltd | Hospitality | 2021 |
| Archie John Financial Solutions Ltd | Financial services | 2018 |
| Architecture Unknown Limited | Professional & scientific | 2016 |
| Archive Bar and Bottle Limited | Wholesale & retail | 2018 |
| Archway Education Limited | Extraterritorial | 2023 |
| Arctane Business Consultancy Ltd | Professional & scientific | 2026 |
| Arctic AC Ltd | Construction | 2025 |
| Arctic FOX Consultancy Services Limited | Professional & scientific | 2018 |
| Arden Court (Bramhall) Association Limited | Real estate | 1961 |
| Ardent Capital Ltd | Extraterritorial | 2022 |
| Ardent Care & Support Ltd | Health & social care | 2023 |
| Ardent Homes Limited | Construction | 2020 |
| Ardex Group Ltd | Administrative & support | 2024 |
| Areeba (UK) Limited | Other services | 2012 |
| Argyll Management Consultants Ltd | Information & communication | 2021 |
| Arham Management Ltd | Financial services | 2020 |
| Arhase Advisory Limited | Financial services | 2025 |
| Aria Land Limited | Real estate | 2006 |
| Aria Technology Holdings Limited | Professional & scientific | 2007 |
| Aricelestial Breeding Limited | Agriculture & fishing | 2026 |
| Arif Canpolat Healthy Smiles Ltd | Administrative & support | 2025 |
| Arise & Rise DUO Limited | Real estate | 2025 |
| Arishan Ltd | Wholesale & retail | 2022 |
| Arkatrove Empire Limited | Real estate | 2021 |
| Arkatrove Limited | Wholesale & retail | 2020 |
| Arktech Enterprise Limited | Wholesale & retail | 2021 |
| Arlex Investments Limited | Professional & scientific | 2019 |
| Arlington Dental and Radiology Services Ltd | Health & social care | 2020 |
| Armadillo Property Services Limited | Real estate | 2014 |
| Armenique Bakery Limited | Hospitality | 2023 |
| Armst & Co Ltd | Wholesale & retail | 1994 |
| Arshaly Jino Ltd | Real estate | 2017 |
| Art of Living Foundation (UK) | Health & social care | 2009 |
| Artharise Ltd | Professional & scientific | 2026 |
| Arthur's Toy Box Limited | Wholesale & retail | 2020 |
| Artisan Hampers Limited | Wholesale & retail | 2020 |
| Artisan Nutrition Limited | Wholesale & retail | 2018 |
| ARU Smiling Limited | Health & social care | 2024 |
| Aruna Investment Properties Limited | Real estate | 2023 |
| AS Aircraft Engineering Ltd | Manufacturing | 2013 |
| AS Capital Group Ltd | Professional & scientific | 2026 |
| AS Implants Ltd | Health & social care | 2025 |
| AS Spectre Ltd | Health & social care | 2026 |
| Asal Lavita Limited | Hospitality | 2024 |
| Asap Logistics UK Limited | Transport & logistics | 1996 |
| ASB4 Ltd | Professional & scientific | 2020 |
| Asfs Holdings Ltd | Real estate | 2020 |
| ASG Renovation & Engineering Ltd | Wholesale & retail | 2021 |
| Ashburrow Limited | Real estate | 1983 |
| Ashcroft Creative Design Limited | Professional & scientific | 2021 |
| Ashley Carpets (Lymm) Limited | Administrative & support | 1997 |
| Ashley DOW Ltd | Wholesale & retail | 2012 |
| Ashley Mowers Limited | Extraterritorial | 2003 |
| Ashton Realtor Limited | Construction | 2022 |
| ASK Legal Solicitors Ltd | Professional & scientific | 2014 |
| ASM Stays Ltd | Real estate | 2026 |
| ASO Style Barber Ltd | Other services | 2025 |
| Aspect Property Consultancy Ltd | Professional & scientific | 2014 |
| ASR Developments Ltd | Construction | 2024 |
| ASR Manchester Limited | Health & social care | 2022 |
| Assad and Nadia Investments Ltd | Real estate | 2020 |
| ASSIST2MARKET Ltd | Real estate | 2026 |
| Astermatt Limited | Households | 1999 |
| Astral Therapies Ltd | Education | 2021 |
| AT Home Outlet Ltd | Wholesale & retail | 2010 |
| At&N Limited | Health & social care | 2020 |
| Ateeq Farooq Ltd | Health & social care | 2017 |
| Ateeqa L Ltd | Wholesale & retail | 2025 |
| Atilla's Barber Ltd | Other services | 2022 |
| Atkinson Autos Limited | Wholesale & retail | 2012 |
| Atkinson Property Management Limited | Real estate | 2016 |
| Atlantic Courriers Limited | Transport & logistics | 2015 |
| Atlantic Enterprises Ltd | Transport & logistics | 2026 |
| Atlas Studios Ltd | Arts & recreation | 2015 |
| Atlasroute Logistics Ltd | Wholesale & retail | 2025 |
| Atomic Group Limited | Administrative & support | 2016 |
| Atomica Group Ltd | Real estate | 2024 |