| Ashram Ventures Limited | Professional & scientific | 2022 |
| Ashtex Limited | Construction | 1998 |
| Ashton Assets Holdings Ltd | Financial services | 2019 |
| Ashwinkrishna Limited | Construction | 2019 |
| Asian Foods London Limited | Wholesale & retail | 2014 |
| Asian Fruit and VEG Ltd | Wholesale & retail | 2018 |
| Asili Limited | Real estate | 2020 |
| ASK Acquisitions Limited | Real estate | 2018 |
| ASK Maintenance Ltd | Households | 2026 |
| ASK Outlets (Holdings) Limited | Financial services | 2022 |
| ASK Outlets (Properties) Ltd | Real estate | 2024 |
| Askp Properties Ltd | Real estate | 2019 |
| ASL CB Ltd | Hospitality | 2023 |
| ASM Residences Ltd | Real estate | 2021 |
| Asnani Ltd | Health & social care | 2019 |
| Aspan Developments Limited | Real estate | 2013 |
| Aspan Properties Ltd | Real estate | 2019 |
| Aspan Properties NO 2 Limited | Real estate | 2020 |
| Aspirante Limited | Construction | 2023 |
| Aspire 2 BE Ltd | Health & social care | 2018 |
| Aspire Overseas Education Limited | Education | 2021 |
| Aspire Services PVT Ltd | Administrative & support | 2017 |
| Asser Accounting Services Ltd | Professional & scientific | 2013 |
| Assetguard Property Consultants Limited | Real estate | 2000 |
| Assetmap.Io Limited | Information & communication | 2014 |
| Assured HR Limited | Administrative & support | 2010 |
| AST Abode Ltd | Real estate | 2023 |
| Aston Reeve Finance Ltd | Administrative & support | 2025 |
| Aston Reeve Limited | Financial services | 2018 |
| Astro Customs Ltd | Wholesale & retail | 2021 |
| Astroo Construction Ltd | Construction | 2022 |
| Astrotech Solutions Ltd | Wholesale & retail | 2013 |
| ASV Retail Limited | Wholesale & retail | 2017 |
| AT Construction & Builder Ltd | Construction | 2022 |
| AT Ease Cornwall Limited | Wholesale & retail | 2017 |
| ATA Khan & Co Ltd | Professional & scientific | 2010 |
| Atari Accountants Limited | Professional & scientific | 2025 |
| Atelier Reverie Ltd | Manufacturing | 2025 |
| Atelier Ruchi Ltd | Professional & scientific | 2020 |
| Atha Hospitality Ltd | Hospitality | 2026 |
| Atha Wellness Ltd. | Wholesale & retail | 2014 |
| Atkinson Medical Consulting Ltd | Health & social care | 2010 |
| Atlas Creative Limited | Manufacturing | 2022 |
| Atlas VIP Cars Services Ltd | Wholesale & retail | 2018 |
| Atmospherics SFX Limited | Information & communication | 2022 |
| Atob Solutions Ltd | Information & communication | 2023 |
| Atris Property Investments Ltd | Real estate | 2022 |
| ATS England Ltd | Extraterritorial | 2018 |
| ATS International Ltd | Administrative & support | 2018 |
| Attende Limited | Administrative & support | 2025 |
| Audace Ltd | Information & communication | 2023 |
| Audiomotion Electronics UK Limited | Administrative & support | 2024 |
| August Harvest Limited | Construction | 2000 |
| AURA34 Limited | Other services | 2017 |
| Aurakai Limited | Real estate | 2025 |
| Aurelius Gold Ltd | Real estate | 2022 |
| Aureon Consultancy Limited | Information & communication | 2025 |
| Aurigah Limited | Information & communication | 2026 |
| Auronova Consulting Limited | Other services | 2023 |
| Autism Assessment and Advocacy Ltd | Health & social care | 2026 |
| Auto Detailers Ltd | Administrative & support | 2025 |
| Auto Hub L&H Limited | Wholesale & retail | 2026 |
| Auto Lisboa Limited | Wholesale & retail | 2008 |
| Auto Recovery 247 Ltd | Transport & logistics | 2024 |
| Auto Technics UK Limited | Wholesale & retail | 1996 |
| Autolegends Ltd | Wholesale & retail | 2009 |
| Automotive and Tractor Spares England Limited | Extraterritorial | 2003 |
| Autosphere Group Limited | Wholesale & retail | 2023 |
| AV (Bees) Limited | Wholesale & retail | 2010 |
| AVA Nails and Beauty Ltd | Other services | 2025 |
| Avaa Limited | Wholesale & retail | 2022 |
| Avakalan Limited | Information & communication | 2025 |
| Avanchets Services Ltd | Professional & scientific | 2018 |
| Aven Holdings Limited | Financial services | 2025 |
| Aventis Consulting Limited | Professional & scientific | 2010 |
| Aventure IT Solutions Ltd | Information & communication | 2014 |
| Avenue 25 Consultants Limited | Extraterritorial | 1998 |
| Average Labs Ltd | Professional & scientific | 2022 |
| Averkiou Business Consultants Limited | Professional & scientific | 2017 |
| Avery ROW Holdings Limited | Financial services | 2021 |
| Avesta Films Limited | Information & communication | 2021 |
| Avisai Ltd | Information & communication | 2022 |
| Avks Events Ltd | Administrative & support | 2026 |
| Avni Limited | Wholesale & retail | 2008 |
| Avon Court (Hatchend) Residents Association Limited | Real estate | 1988 |
| Avondale Business Services Ltd | Professional & scientific | 2015 |
| AVR Holdings Ltd | Financial services | 2022 |
| AVT Properties Limited | Real estate | 2015 |
| Avyan Ltd | Information & communication | 2012 |
| Avyani Limited | Administrative & support | 2021 |
| Avyom Consultancy Ltd | Administrative & support | 2022 |
| AW Music Associates Limited | Arts & recreation | 2015 |
| Awards & Engraving London Ltd | Wholesale & retail | 2023 |
| Axiom Men's Jewellery Ltd | Manufacturing | 2025 |
| Axironx Ltd | Wholesale & retail | 2026 |
| Axis Dental Academy Ltd | Education | 2025 |
| Axon Outsourcing Ltd | Professional & scientific | 2011 |
| AY Trading Limited | Hospitality | 2013 |
| AYA XP Limited | Education | 2018 |
| Ayalay Limited | Financial services | 2025 |