| Andante Travels Transport Company Limited | Transport & logistics | 2012 |
| Anderbury Limited | Hospitality | 1990 |
| Anderson Griffin Limited | Professional & scientific | 2020 |
| Anderson UK Holdings Limited | Financial services | 2019 |
| Anderson Wealth Advice Limited | Financial services | 2015 |
| Anderval Limited | Education | 2016 |
| Andnan Ltd | Information & communication | 2024 |
| Andover Retail Ltd | Wholesale & retail | 2022 |
| Andoversford Garage Ltd | Wholesale & retail | 2017 |
| Andre-Dzh Ltd | Transport & logistics | 2016 |
| Andreescu House Ltd | Transport & logistics | 2017 |
| Andrei Udrea Ltd | Transport & logistics | 2020 |
| Andrew Allen Design Limited | Professional & scientific | 2009 |
| Andrew Bird Hearing Ltd | Health & social care | 2007 |
| Andrew Bullock Agriculture Limited | Administrative & support | 2005 |
| Andrew Fleming Associates Limited | Real estate | 2003 |
| Andrew Hazell Properties Ltd | Hospitality | 2007 |
| Andrew Horton Limited | Professional & scientific | 2016 |
| Andrew Mccusker Notary Services Limited | Professional & scientific | 2019 |
| Andrew Toumazou Limited | Other services | 2003 |
| Andrews Associates Limited | Professional & scientific | 2001 |
| Andrews Associates Services Limited | Administrative & support | 2015 |
| Andrews of Gloucester Ltd | Real estate | 2020 |
| Andrey C Transport Limited | Transport & logistics | 2018 |
| Andros Consulting Limited | Professional & scientific | 2021 |
| Andy Croft Ltd | Professional & scientific | 2026 |
| Andy Hill & Sons Family Butchers Limited | Wholesale & retail | 2009 |
| Andy Kime Consulting Ltd | Professional & scientific | 2025 |
| Andy Youell Services Limited | Information & communication | 2024 |
| Andysco Ltd | Other services | 2010 |
| ANE Care Professional Ltd | Health & social care | 2025 |
| Anesco Solar Rooftop 1 Limited | Energy | 2015 |
| Anew Travel International Limited | Administrative & support | 2007 |
| Aney Air Conditioning Ltd | Construction | 2026 |
| ANG Supply Chain Design Limited | Professional & scientific | 2009 |
| Angel & SON Transport Limited | Transport & logistics | 2017 |
| Angel Day Nursery (UK) Limited | Health & social care | 2014 |
| Angela Paull and Co Limited | Professional & scientific | 2009 |
| Angelfish Digital Marketing Ltd | Professional & scientific | 2026 |
| Angelfish Market Research Limited | Professional & scientific | 2011 |
| Angell Group Services Limited | Professional & scientific | 2025 |
| Angell Holdings Ltd | Professional & scientific | 2017 |
| Angels 4 Angels Limited | Professional & scientific | 2012 |
| Angels Home Care (Kent) Limited | Health & social care | 2003 |
| Angiovisium, Diagnostics and Solutions Limited | Health & social care | 2023 |
| Anglio Limited | Wholesale & retail | 2017 |
| Anglo Overseas Commerce Limited | Education | 1994 |
| Angus Day LLP | | 2015 |
| Anidea Business Finance Ltd | Financial services | 2024 |
| Animation Associates Ltd | Information & communication | 2016 |
| Anise Cashmere Ltd | Wholesale & retail | 2008 |
| Ankasa Limited | Information & communication | 2015 |
| Anna Carroll Creative Limited | Other services | 2014 |
| Anna Marie Designs Limited | Wholesale & retail | 2021 |
| Anna Symonds Limited | Real estate | 2025 |
| Anna-Paula Ltd | Manufacturing | 2024 |
| Annamotion Limited | Other services | 2003 |
| Annascaul Ltd | Professional & scientific | 2024 |
| Anne Brinkhoff Limited | Professional & scientific | 2021 |
| Anne Forrestal (Holdings) Limited | Financial services | 2021 |
| Anne Mcintyre Limited | Health & social care | 2011 |
| Anne Stokes Consultancy Ltd | Education | 2016 |
| Annecy Court Management Company Limited | Households | 2006 |
| Annette Sosna (Holdings) Limited | Real estate | 1993 |
| Annodeel Limited | Professional & scientific | 2021 |
| Anon Clothing & Consulting Limited | Professional & scientific | 2007 |
| Another Life Ltd | Information & communication | 2025 |
| Another Limited Company Ltd | Construction | 2019 |
| Another Plane Limited | Professional & scientific | 2022 |
| Anotherland Ventures Limited | Information & communication | 2024 |
| Antani Solutions Ltd | Other services | 2018 |
| Antelope Partners Limited | Financial services | 2021 |
| Anthem Global Ltd | Administrative & support | 2025 |
| Anthony Green Limited | Other services | 2007 |
| Anthony Harris Ltd | Professional & scientific | 2009 |
| Anthony Macpherson Construction Ltd | Construction | 2010 |
| Anthony Paul Ltd | Professional & scientific | 2011 |
| Anti-Friction Technology Limited | Professional & scientific | 2001 |
| Antiqualia Limited | Real estate | 2009 |
| Anton Tattoo Art Limited | Arts & recreation | 2025 |
| Antony Grice (Plumbing & Heating) Limited | Construction | 1995 |
| Antrak Limited | Financial services | 2010 |
| Anya Cleaning Ltd | Other services | 2015 |
| Anya Enterprises Limited | Real estate | 2022 |
| Anycolour Coatings Limited | Manufacturing | 2011 |
| Anysphere UK Ltd | Information & communication | 2025 |
| Anytime Sunbeds (Glos) Ltd | Administrative & support | 2009 |
| Anzû Productions Ltd | Information & communication | 2020 |
| AOA Residencies Ltd. | Real estate | 2022 |
| AOC Solutions Ltd | Professional & scientific | 2025 |
| AOJ Design Limited | Information & communication | 2007 |
| Aotc Services Limited | Other services | 2025 |
| AP Filtration Limited | Manufacturing | 1985 |
| AP SD Twelve Limited | Wholesale & retail | 2025 |
| Ap&Co Holdings Ltd | Financial services | 2023 |
| Aperio Business Consultancy Limited | Professional & scientific | 2007 |
| Apex Autohaüs Ltd | Wholesale & retail | 2022 |
| Apex Aviation Engine Services UK Limited | Manufacturing | 2020 |
| Apex Business Improvement Solutions Ltd. | Professional & scientific | 2015 |
| Apex Cheltenham Ltd | Administrative & support | 2023 |