| Alphe Ltd | Real estate | 2024 |
| Altenburg Property Management Ltd | Real estate | 2018 |
| Alternative Fuel Diagnostics Ltd | Wholesale & retail | 2019 |
| Althom Properties Limited | Real estate | 2023 |
| Altitude 50 Ltd | Administrative & support | 2016 |
| Altrudana Limited | Professional & scientific | 2019 |
| Altura Developments Limited | Construction | 2010 |
| Alva Motors Ltd | Wholesale & retail | 2026 |
| Alvin AFH Limited | Professional & scientific | 2022 |
| ALW Service Ltd | Wholesale & retail | 2025 |
| Alwakel Ltd | Construction | 2022 |
| Always Beauty Ltd | Health & social care | 2021 |
| Alympic Builders Limited | Construction | 2005 |
| ALZ Care Limited | Manufacturing | 2021 |
| AM 2 PM Cleaning Services Ltd | Transport & logistics | 2025 |
| AM Comfort Ltd | Hospitality | 2023 |
| AM Construction & Engineering Limited | Professional & scientific | 2016 |
| AM Fit Ltd | Extraterritorial | 2017 |
| AM Flying Ltd | Transport & logistics | 2019 |
| AM Medical Supplies Limited | Other services | 2023 |
| AM Premier Assets Limited | Real estate | 2019 |
| Amalu Ltd | Arts & recreation | 2024 |
| Amanah Pharmaceuticals Limited | Wholesale & retail | 2025 |
| Amani Downs Limited | Hospitality | 2025 |
| Amare Educo Ltd | Real estate | 2021 |
| Amax Contracting Limited | Professional & scientific | 2013 |
| Amazing Concept Limited | Professional & scientific | 2023 |
| Amazing FOX Limited | Professional & scientific | 2020 |
| Amazing Glaze Limited | Construction | 1996 |
| Amazingstays Ltd | Hospitality | 2023 |
| AMB London Limited | Arts & recreation | 2013 |
| Amber Marsella Group Limited | Construction | 2026 |
| Amber Marsella Ltd | Construction | 2010 |
| Amber Plumbers Limited | Construction | 2021 |
| Amberley Consulting Ltd | Administrative & support | 2009 |
| Amberline Design Limited | Construction | 1985 |
| Amberwood Grove Residents Limited | Households | 2025 |
| Amberwood Investments Limited | Professional & scientific | 2021 |
| Ambika Security Limited | Other services | 1988 |
| Ambition Events Ltd | Other services | 2022 |
| Amcl (2013) Limited | Extraterritorial | 2013 |
| Amcn Limited | Information & communication | 2012 |
| Amcp Research Ltd | Professional & scientific | 2025 |
| Amdib Limited | Professional & scientific | 2022 |
| Ameeq Interiors Ltd | Professional & scientific | 2025 |
| Amelie Place (Esher) Limited | Households | 2014 |
| AMELIOR8 Healthcare Limited | Professional & scientific | 2021 |
| American Village Pizza Ltd | Hospitality | 2025 |
| AMI Software Limited | Information & communication | 2012 |
| Amicitia Limited | Information & communication | 2026 |
| Amideus Investments Ltd | Real estate | 2016 |
| Amis DU VIN Ltd | Wholesale & retail | 1999 |
| AML Developments Limited | Construction | 2017 |
| AML Transport Consultants Limited | Professional & scientific | 2022 |
| Amogha Foods Ltd | Manufacturing | 2025 |
| AMP Mark Pilling Limited | Professional & scientific | 2021 |
| Amplified Strength Ltd | Wholesale & retail | 2023 |
| Amrap Athletic Goods Ltd | Wholesale & retail | 2019 |
| Amrest Property Development Ltd | Construction | 1996 |
| AMS & Co Consulting Ltd | Professional & scientific | 2012 |
| Amstel Bros Ltd | Real estate | 2017 |
| AMT Capital Ltd | Professional & scientific | 2017 |
| Amtrexx Security Limited | Construction | 2006 |
| An@Lysethat Ltd | Information & communication | 2016 |
| Anaesthesia 247 Ltd | Health & social care | 2024 |
| Anahata Innovation Ltd | Professional & scientific | 2017 |
| Anamaria Investments Ltd | Real estate | 2021 |
| Ananke Tyche Ltd | Wholesale & retail | 2024 |
| Ancestral Legacies Limited | Arts & recreation | 2004 |
| Anchoris Ltd | Professional & scientific | 2025 |
| Ancient Natural Healthcare Ltd | Health & social care | 2026 |
| Andarzgo Ltd | Hospitality | 2025 |
| Andene Consulting Limited | Construction | 2017 |
| Andhurst Court (Kingston Upon Thames) Limited | Real estate | 1996 |
| Andira Ltd | Construction | 2021 |
| Andira Property Ltd | Real estate | 2024 |
| Andrea Burnley Limited | Administrative & support | 2017 |
| Andreas VON Einsiedel Archive Limited | Professional & scientific | 2003 |
| Andrew Cobb Limited | Health & social care | 2010 |
| Andrew Dowley Limited | Real estate | 2023 |
| Andrewsoft Limited | Information & communication | 2021 |
| Andthentwo Ltd | Information & communication | 2026 |
| Andwat Developments Ltd | Real estate | 2022 |
| Andy Rowe Associates Limited | Wholesale & retail | 2011 |
| Anedottica Limited | Hospitality | 2018 |
| Angelicus Care Company Ltd | Professional & scientific | 2018 |
| Angelis Consultant Solutions Ltd | Information & communication | 2023 |
| Anglo Belge Ltd | Administrative & support | 2025 |
| Anglo Celtic Developments Limited | Professional & scientific | 2020 |
| Anglofive Ltd | Professional & scientific | 2018 |
| Aniksthetics Medical & Investments Ltd | Financial services | 2026 |
| Animation Events Limited | Other services | 2016 |
| Anjos Limited | Wholesale & retail | 2015 |
| Anne Boleyn Court Residents Association Limited(The) | Households | 1985 |
| Anne Nails & Spa Epsom Ltd | Other services | 2024 |
| Anneler Kulubu Ltd | Information & communication | 2026 |
| Annetts Build Co. Ltd | Construction | 2026 |
| Annexe Contractors Ltd | Construction | 2023 |
| Annie Jose Limited | Information & communication | 2025 |
| Anogaa Ltd | Professional & scientific | 2020 |