| A.J. Wintergreen Limited | Manufacturing | 2019 |
| A.J.Fortescue & SON Limited | Construction | 1954 |
| A.L.I Ultrasound Limited | Health & social care | 2016 |
| A.M. Gooch Limited | Other services | 2004 |
| A.R.C. Rural Services Limited | Agriculture & fishing | 2003 |
| A.R.E. Services Limited | Construction | 2018 |
| A.S. Architecture Ltd | Professional & scientific | 2025 |
| A.S. International Asset Management Limited | Other services | 2020 |
| A.S.Padda Ltd | Manufacturing | 2025 |
| A.T. Garage Services Limited | Wholesale & retail | 2013 |
| A.T. Palmer (Builders & Contractors) Limited | Construction | 1954 |
| A.T. Palmer Developments Ltd | Construction | 2019 |
| A.T. Visuals Limited | Information & communication | 2023 |
| A.T.E.M. Limited | Construction | 2012 |
| A.Y.R Constructions Limited | Construction | 2007 |
| A1 Audio Ashford Limited | Wholesale & retail | 2017 |
| A1 Motorist Centre Ltd | Wholesale & retail | 2005 |
| A1 Nails Ltd | Other services | 2023 |
| A1 Secure Self Storage Limited | Extraterritorial | 2006 |
| A20 Productions Ltd | Information & communication | 2025 |
| A20 Truckstop Limited | Transport & logistics | 2015 |
| A2B Food & Health Ltd | Hospitality | 2022 |
| A2B Technology (UK) Ltd | Information & communication | 2002 |
| A2G22 Limited | Administrative & support | 2025 |
| A2Z Trading Retail Limited | Wholesale & retail | 2022 |
| A3J Property Limited | Real estate | 2023 |
| A40 Packaging Limited | Administrative & support | 2007 |
| AA Beauty Ltd | Other services | 2018 |
| AA Consultants Ltd | Professional & scientific | 2025 |
| AA Logistics Inc Ltd | Transport & logistics | 2020 |
| AA Supplies Ltd | Wholesale & retail | 2021 |
| AAA Futures Development Limited | Real estate | 2025 |
| AAA Shipping Limited | Transport & logistics | 2023 |
| Aadc Solutions Limited | Information & communication | 2022 |
| Aadi IT Services Ltd | Information & communication | 2025 |
| Aakai Limited | Wholesale & retail | 2024 |
| AAL Consultancy Ltd | Other services | 2020 |
| Aandr Terravers Ltd | Professional & scientific | 2025 |
| Aaravi Hajur Ltd | Real estate | 2024 |
| Aardvark Aerospace Ltd | Professional & scientific | 2010 |
| Aarhus Limited | Real estate | 2018 |
| Aark Property Investment Ltd | Real estate | 2021 |
| Aaron Mcnamara Limited | Water & waste | 2025 |
| Aarshii Designs Ltd | Manufacturing | 2023 |
| Aarya P Limited | Information & communication | 2025 |
| Aastha Real Estate Limited | Real estate | 2026 |
| Aaunel Limited | Professional & scientific | 2017 |
| AB IT Consultancy Ltd | Information & communication | 2015 |
| Abacus Bookkeeping (UK) Limited | Professional & scientific | 2003 |
| Abacus S.E Limited | Construction | 2008 |
| Abacus Storage Limited | Real estate | 2015 |
| Abandon Music Publishing Limited | Information & communication | 2011 |
| Abandon Music Recordings (UK) Limited | Information & communication | 2007 |
| Abbey Drylining (South East) Ltd. | Construction | 2013 |
| Abbeyabs Limited | Public administration | 2025 |
| Abbeygate Drain Care Limited | Water & waste | 2006 |
| Abbie Fields (Brabourne Lees) Management Limited | Households | 2019 |
| Abby Waters Management Limited | Real estate | 2010 |
| Abdul Property Holdings Limited | Real estate | 2026 |
| Abeeha Motors Ltd | Wholesale & retail | 2025 |
| Abel Accountants Ltd | Professional & scientific | 2023 |
| Abel Accounting Ltd | Professional & scientific | 2025 |
| Abermell Limited | Households | 1996 |
| Abertillery Holdings Limited | Financial services | 1986 |
| Abeta Accountancy Ltd | Professional & scientific | 2005 |
| Abetterme Transformation CIC | Education | 2025 |
| Abidi Fast Foods Ltd | Hospitality | 2016 |
| Abiker Limited | Wholesale & retail | 2003 |
| ABL Storage Ltd | Transport & logistics | 2024 |
| Able Acoustics Limited | Professional & scientific | 2015 |
| Able PDM Holdings Limited | Financial services | 2018 |
| Ablenest Care Limited | Health & social care | 2026 |
| ABM Commercial Ltd | Construction | 2020 |
| ABM Cooling Ltd | Construction | 2024 |
| ABM New Build Ltd | Construction | 2020 |
| Abof Group Limited | Professional & scientific | 2021 |
| Abof Limited | Professional & scientific | 2013 |
| Abounded Limited | Real estate | 2023 |
| About Return Ltd | Professional & scientific | 2021 |
| Above ALL Else Limited | Professional & scientific | 2023 |
| Above PAR (Properties) Limited | Real estate | 2004 |
| Abrahamsen Jones Professional Services Limited | Information & communication | 2014 |
| Abre Traders Ltd | Wholesale & retail | 2026 |
| ABS Mini Market Ltd | Wholesale & retail | 2026 |
| Absen Rope Access Specialists Limited | Construction | 2008 |
| Absolair Filtration Limited | Manufacturing | 1984 |
| Absolute 0 Refrigeration Limited | Manufacturing | 2025 |
| Absolute Accounting Limited | Professional & scientific | 2015 |
| Absolute Executive Search Limited | Professional & scientific | 1997 |
| Absolute Eyes BYP Limited | Health & social care | 2017 |
| Absolute Financial Group Limited | Financial services | 2019 |
| Absolute Financial Management Limited | Financial services | 2004 |
| Absolute Fitness Limited | Arts & recreation | 1999 |
| Absolute Notaries Limited | Education | 2019 |
| Absowebly Limited | Information & communication | 2011 |
| Abstract Tiling Limited | Construction | 2008 |
| Abyus Ltd | Professional & scientific | 2022 |
| AC Builders Ltd | Construction | 2019 |
| AC Scenic Painting Ltd | Arts & recreation | 2023 |
| ACA Bar Management Limited | Transport & logistics | 2005 |