| A&S Assets Ltd | Real estate | 2024 |
| A&S Build & Design Ltd | Construction | 2025 |
| A&T Accountants Ltd | Professional & scientific | 2015 |
| A-Creative Limited | Professional & scientific | 2002 |
| A-Ogun & Sons Limited | Construction | 2025 |
| A-Ogun Limited | Construction | 2007 |
| A-Z Move Ltd | Transport & logistics | 2020 |
| A-Z One Stop Shop Ltd | Wholesale & retail | 2023 |
| A. Jones & Co Ltd | Professional & scientific | 2011 |
| A. K. Whelan PUB Co. Ltd | Hospitality | 2020 |
| A.J. Mckechnie Limited | Real estate | 1973 |
| A.K Construction of London Ltd | Construction | 2018 |
| A.K Hirani Group Limited | Wholesale & retail | 2024 |
| A.M.S. (GB) Limited | Other services | 2003 |
| A.R.S Export Ltd | Wholesale & retail | 2018 |
| A.R.T Property Maintenance Limited | Administrative & support | 2010 |
| A.Rasa Construction Ltd | Construction | 2023 |
| A.S. Logistics Group Limited | Transport & logistics | 2024 |
| A.S. Real Estate Group Limited | Real estate | 2025 |
| A.S.H. Capital Estates Limited | Real estate | 2024 |
| A.V. Property Services Limited | Construction | 2009 |
| A12 Design Ltd | Professional & scientific | 2025 |
| A2A Business Ltd | Professional & scientific | 2004 |
| A2Z Platform Ltd | Wholesale & retail | 2021 |
| AA Ecommerce Limited | Wholesale & retail | 2026 |
| AA Exotics Ltd | Wholesale & retail | 2021 |
| AA Homelea Limited | Real estate | 2025 |
| AA Redec & Installations Ltd | Construction | 2025 |
| AA Services London Limited | Wholesale & retail | 2012 |
| AA23 Property Limited | Real estate | 2025 |
| AAN Private Ltd | Wholesale & retail | 2025 |
| Aariv Consultancy Limited | Wholesale & retail | 2025 |
| AB FAB Catering and Events Limited | Hospitality | 2025 |
| AB Strategy & Consulting Limited | Professional & scientific | 2025 |
| Abbh Limited | Hospitality | 2025 |
| Abbies Driver Training Limited | Education | 2017 |
| ABC Behaviour Ltd | Education | 2013 |
| ABC Wills Limited | Professional & scientific | 2021 |
| Abcd Wizard Limited | Wholesale & retail | 2000 |
| Abell Contracting Limited | Administrative & support | 2011 |
| ABI Lifts Limited | Manufacturing | 2014 |
| Abidin & Co. Ltd | Professional & scientific | 2020 |
| Abidin Associates Ltd | Professional & scientific | 2020 |
| Able Felt Roofing Limited | Construction | 2002 |
| Able Wealth Management Ltd | Financial services | 2011 |
| Abode GAS Ltd | Construction | 2017 |
| Absha Managed Solutions Limited | Construction | 2024 |
| Absha Project Ltd. | Transport & logistics | 2018 |
| ABY Decorating Ltd | Construction | 2014 |
| Abyi Services Ltd | Transport & logistics | 2024 |
| ABZ Ventures Ltd | Wholesale & retail | 2025 |
| AC ACC Limited | Professional & scientific | 2023 |
| AC Financial Planning Limited | Financial services | 2022 |
| AC Property Tree Ltd | Real estate | 2021 |
| Acacia Raddiana Limited | Manufacturing | 2025 |
| Academic Growth Partners Ltd | Information & communication | 2026 |
| Academy of South Indian Music (London) Ltd | Health & social care | 2013 |
| Academy Roofing Supplies Limited | Wholesale & retail | 2006 |
| Access Flooring Systems Ltd | Construction | 2019 |
| Access to Advocacy CIC | Health & social care | 2025 |
| Accommodate Property Services Limited | Real estate | 2006 |
| Accommodation Centre Limited | Real estate | 1998 |
| Accountants and Tax Management Consultants Ltd | Professional & scientific | 2017 |
| Accrasystem Limited | Manufacturing | 1987 |
| Ace Beauty & Aesthetics Ltd | Other services | 2026 |
| Achkoni Ltd | Construction | 2007 |
| Acka Properties Ltd | Real estate | 2016 |
| Acme Consultants Limited | Construction | 2026 |
| Acmh Limited | Information & communication | 2018 |
| Acorn Public House Limited | Hospitality | 2025 |
| Acorn Talent Partners Ltd | Administrative & support | 2026 |
| ACP Electrical Contracts Limited | Construction | 2012 |
| Acraside Consultancy Ltd | Professional & scientific | 2017 |
| Acropolis Vent Mechanical Ltd | Construction | 2023 |
| Action Industrial Cleaning Services (UK) Limited | Administrative & support | 1999 |
| Action on Blood Limited | Other services | 2008 |
| Actis Properties and Lettings Ltd | Real estate | 2025 |
| Active Counselling Services Limited | Health & social care | 2012 |
| Active Office Seating Limited | Manufacturing | 2003 |
| Active Orthodontics Limited | Health & social care | 2006 |
| Actual Cleaning Co. Limited(The) | Extraterritorial | 1974 |
| Actual Group Limited | Extraterritorial | 2018 |
| Actual Removal Company Ltd | Extraterritorial | 1988 |
| Actual Support Services Limited | Water & waste | 2000 |
| Actuarial Advisory Services Limited | Financial services | 2011 |
| Acura Group Ltd | Construction | 2022 |
| AD Cleaning Group Ltd | Administrative & support | 2025 |
| AD Construct Ltd | Construction | 2026 |
| AD Property Strategy Consulting Limited | Professional & scientific | 2015 |
| Adam Enterprises Limited | Construction | 1969 |
| Adam&Aizah Ltd | Wholesale & retail | 2022 |
| Adam's Mobility Services Limited | Wholesale & retail | 2007 |
| Adams Concrete Pumping Ltd | Construction | 2026 |
| Adan Group Ltd | Construction | 2020 |
| Adapt-Rugby Limited | Arts & recreation | 2011 |
| Adaptive Construction Services Limited | Construction | 2019 |
| Addx Ltd | Wholesale & retail | 2024 |
| Adea Solutions Ltd | Public administration | 2023 |
| Adele Ward Communications Ltd | Professional & scientific | 2009 |
| Adept Dental Property Limited | Households | 2023 |