| A Touch of RHO Ltd | Professional & scientific | 2021 |
| A Ucyigit Ltd | Extraterritorial | 2021 |
| A Y Pinnacles Ltd | Health & social care | 2021 |
| A&A London Residential LLP | | 2026 |
| A&J Heath Property Limited | Real estate | 2025 |
| A&J Telecoms Ltd | Construction | 2024 |
| A&K Sales Refurbs & Maintenance Ltd | Construction | 2025 |
| A&L Investment F Ltd | Real estate | 2025 |
| A&L Property Ltd | Real estate | 2017 |
| A&M Team Ltd. | Extraterritorial | 2015 |
| A&V Property Consultants Limited | Financial services | 2024 |
| A&Z Chai UK Ltd | Hospitality | 2024 |
| A-Cube Ventures Limited | Information & communication | 2024 |
| A-Sonic Logistics (UK) Limited | Administrative & support | 2017 |
| A-Z Translation & Interpreting Services Ltd | Professional & scientific | 2002 |
| A. Ransley Limited | Financial services | 2003 |
| A.E. Electrical Limited | Construction | 1997 |
| A.E.Lawson Plumbing & Heating Ltd | Administrative & support | 2013 |
| A.I Electric Services Limited | Construction | 2023 |
| A.L.L Mechanical Services Ltd | Professional & scientific | 2026 |
| A.L.L.I Collective Limited | Public administration | 2026 |
| A.L.R. Legal Services Ltd | Professional & scientific | 2008 |
| A.M.S. International Freight Ltd | Transport & logistics | 1996 |
| A.R.R. Ltd | Wholesale & retail | 2007 |
| A.S Garden Services Ltd | Administrative & support | 2023 |
| A.S. Practice Management Ltd | Administrative & support | 2025 |
| A.W Football Coaching Ltd | Education | 2022 |
| A2 Delivery Ltd | Transport & logistics | 2017 |
| A2 Motorcycle Centre Ltd | Wholesale & retail | 2013 |
| A2JS Technologies Ltd | Information & communication | 2025 |
| A3 Electrical Contractors Ltd | Construction | 2026 |
| A3 Holding Group Ltd | Financial services | 2026 |
| AA Nursing Care Limited | Health & social care | 2013 |
| AAA Auto Sales & Rentals Ltd | Wholesale & retail | 2025 |
| AAA Consultancy Services Ltd | Professional & scientific | 2004 |
| AAA Property Design 2 Build Ltd | Construction | 2019 |
| Aaaa Cleaning Removals Limited | Administrative & support | 2020 |
| AAB Home Improvement Ltd | Construction | 2021 |
| Aadar Services Ltd | Construction | 2022 |
| Aadhityan Retail Ltd | Wholesale & retail | 2025 |
| AAI Project Solutions Ltd | Information & communication | 2016 |
| Aakins (UK) Limited | Transport & logistics | 2025 |
| AAR Electrical Maintenance Contractors Limited | Construction | 2025 |
| Aarivanh Ltd | Information & communication | 2026 |
| Aaron Lodge (Grove Park) RTM Company Limited | Real estate | 2016 |
| AAVENUE88 Ltd | Hospitality | 2017 |
| Aayux Ltd | Information & communication | 2026 |
| AB Building Works Ltd | Construction | 2022 |
| AB Change Delivery Limited | Other services | 2017 |
| AB Dickson Designs Ltd | Professional & scientific | 2026 |
| AB Initio Games Limited | Information & communication | 2001 |
| AB Mackenzie Ltd | Professional & scientific | 2022 |
| Abacus Executive Search Limited | Administrative & support | 2013 |
| Abacus Homecare (Bromley) Limited | Extraterritorial | 2010 |
| Abacus London Limited | Professional & scientific | 1987 |
| Abacus Magnetics Real Estate Limited | Other services | 2012 |
| Abary Holdings Limited | Real estate | 2019 |
| Abary Investments Limited | Real estate | 2019 |
| Abary Limited | Real estate | 2025 |
| Abary Properties Limited | Real estate | 2025 |
| ABB Forum Ltd | Agriculture & fishing | 2025 |
| ABB Management Ltd | Other services | 2025 |
| Abbey Park Limited | Households | 1973 |
| Abbey Road (Blocks a B C & D) Flat Management Company Limited | Households | 1994 |
| Abbey Road (Blocks E F & G) Flat Management Company Limited | Households | 1994 |
| Abbotdown Limited | Households | 1995 |
| Abbott Veterinary Physiotherapy Ltd | Professional & scientific | 2021 |
| Abby House Limited | Real estate | 2012 |
| ABC Actuarial Limited | Professional & scientific | 2018 |
| ABC Demolition (Group) Limited | Administrative & support | 2015 |
| ABC Simple Accounting Ltd | Professional & scientific | 2023 |
| Abec Consulting Ltd | Information & communication | 2016 |
| Abel Titchner Associates Ltd | Professional & scientific | 2025 |
| Aberdale Estates Limited | Real estate | 1995 |
| Abervere Ltd | Professional & scientific | 2025 |
| Abhisek Paul Limited | Information & communication | 2011 |
| Abidammy Limited | Public administration | 2022 |
| Abifun Ltd | Health & social care | 2015 |
| Abijany Limited | Professional & scientific | 2026 |
| Abingdon Close Management Limited | Households | 1962 |
| Abington Site Services Limited | Construction | 2013 |
| Able Joinery (London) Limited | Administrative & support | 2001 |
| Ablett Architects Limited | Construction | 2013 |
| ABO Properties Investment Limited | Real estate | 2024 |
| Abphysios Ltd | Other services | 2018 |
| Abrahams Kriger Ltd | Administrative & support | 2022 |
| Abray Properties Ltd | Hospitality | 2025 |
| Abrisham Ltd | Hospitality | 2023 |
| Absolutebenefit Property Ltd | Information & communication | 2023 |
| ABZ Management Limited | Administrative & support | 2002 |
| AC Builders and Plumbing Services Ltd. | Construction | 2021 |
| AC Corporate Communications Limited | Professional & scientific | 2015 |
| AC Express Ltd | Transport & logistics | 2020 |
| Acadia Racing Ltd | Extraterritorial | 2023 |
| Acar Yachting Ltd | Extraterritorial | 2024 |
| ACB Building Contractors Ltd | Construction | 2022 |
| Accelerate Tuition Services Ltd | Education | 2017 |
| Accelerator Marine Ltd | Other services | 2023 |
| Accessible Counselling and Therapy Limited | Health & social care | 2003 |
| Accessup.Ai Ltd | Information & communication | 2024 |