| A & B Landscapes & Garden Maintenance Limited | Administrative & support | 2013 |
| A & C Properties Hampshire Ltd | Financial services | 2026 |
| A & L Dance Academy Limited | Arts & recreation | 2010 |
| A & M Kitchen Manufacturing Ltd | Manufacturing | 2010 |
| A & N Care Limited | Health & social care | 2019 |
| A & S DRY Lining Limited | Construction | 2001 |
| A & T Southern Properties Limited | Real estate | 2025 |
| A & T Tree Care Ltd | Agriculture & fishing | 2002 |
| A 2 B Coatings Ltd | Construction | 2017 |
| A and G T Consulting Ltd | Professional & scientific | 2026 |
| A Barnes Estates Ltd | Real estate | 2023 |
| A Bespoke Life Ltd | Wholesale & retail | 2019 |
| A Bryant Contracting Limited | Professional & scientific | 2017 |
| A C Cooling and Refrigeration Limited | Construction | 2013 |
| A C Coughtrey & SON Limited | Wholesale & retail | 2014 |
| A C Employment Solicitors Limited | Professional & scientific | 2016 |
| A C Motors Service & Repair Centre Ltd | Wholesale & retail | 2011 |
| A C W Engineering Services Limited | Professional & scientific | 1999 |
| A Cloud Guru Ltd | Information & communication | 2015 |
| A Dark Fantasy Ltd | Wholesale & retail | 2024 |
| A Duty Driver Limited | Transport & logistics | 2019 |
| A E M Electrical Limited | Construction | 2018 |
| A F (Maintenance) Holdings Limited | Financial services | 2024 |
| A Foster Building Contractor Ltd | Construction | 2016 |
| A Ghaly Property Ltd | Administrative & support | 2023 |
| A Good Yarn Limited | Wholesale & retail | 2025 |
| A H Freemantle Limited | Other services | 2003 |
| A J S Marine Limited | Transport & logistics | 2008 |
| A J T Bookkeeping Limited | Professional & scientific | 2016 |
| A Jolly Dime Limited | Hospitality | 2025 |
| A Kelso Services Ltd | Wholesale & retail | 2014 |
| A List Kitchens and Bathrooms Limited | Construction | 2017 |
| A Little London Ltd | Hospitality | 2026 |
| A M C V Limited | Real estate | 2021 |
| A M L Enterprises Limited | Arts & recreation | 2012 |
| A M L Land Investments Limited | Financial services | 2018 |
| A M L Property Investments Limited | Real estate | 2015 |
| A M L Property Ventures Limited | Real estate | 2017 |
| A Noble Light Commercials Limited | Wholesale & retail | 2020 |
| A Plus JB Ltd | Information & communication | 2016 |
| A Russell Engineering Limited | Professional & scientific | 2017 |
| A&A Electrical (Hants) Ltd | Construction | 2021 |
| A&A Estates Ltd | Real estate | 2025 |
| A&A Property Maintenance (Hants) Ltd | Construction | 2013 |
| A&B English With Ease Ltd | Education | 2023 |
| A&J Harrison Ltd | Financial services | 2026 |
| A&Je Consultancy Services Limited | Professional & scientific | 2025 |
| A&K Brickwork Limited | Other services | 2016 |
| A&K Restaurants Ltd | Hospitality | 2016 |
| A. Edwards Decorating Solutions Ltd | Construction | 2017 |
| A. J. K. Services Limited | Construction | 1998 |
| A. Shires Decor Limited | Construction | 2017 |
| A.C.N Data & Cctv Installations Ltd | Information & communication | 2024 |
| A.D Cordery Plumbing and Heating Limited | Construction | 2026 |
| A.H.S. (South East) Ltd | Wholesale & retail | 2015 |
| A.I.R Accounting Services Ltd | Professional & scientific | 2024 |
| A.M.C Dorset Ltd | Transport & logistics | 2018 |
| A.S Electrics (Slough) Ltd | Construction | 2023 |
| A.S. Training Associates Ltd | Hospitality | 2016 |
| A.T. Jones & SON Limited | Construction | 1976 |
| A.T.H. Consultancy Limited | Professional & scientific | 2012 |
| A2 - Architecture & Development Ltd | Professional & scientific | 2020 |
| A2A Properties Ltd | Real estate | 2022 |
| A2B Mobility Services Ltd | Transport & logistics | 2026 |
| A3M Designs Limited | Administrative & support | 2002 |
| A470 Commercials Limited | Wholesale & retail | 2016 |
| AA Heating Group Ltd | Manufacturing | 2024 |
| AAH Products (Hampshire) Ltd | Construction | 2023 |
| Aaron Gale Ltd | Professional & scientific | 2026 |
| AB Dental Laboratory Ltd | Manufacturing | 2022 |
| AB Gold Ltd | Health & social care | 2025 |
| ABA Park Lane Services Limited | Professional & scientific | 2012 |
| Abacus Estate Planning Services Limited | Professional & scientific | 2018 |
| Abba Blue Limited | Wholesale & retail | 2025 |
| Abbey Farm Feeds Limited | Agriculture & fishing | 2017 |
| Abbeytech Consultancy Limited | Information & communication | 2007 |
| Abbotstone Financial Solutions LLP | | 2014 |
| Abbotswood Properties Limited | Construction | 1984 |
| ABC Digital Systems Limited | Manufacturing | 2007 |
| Abcan Property Holdings Limited | Construction | 2018 |
| Abcd Newco Limited | Other services | 2025 |
| Abdk Limited | Education | 2000 |
| Aberdeen Domiciliary Specsavers Limited | Wholesale & retail | 2015 |
| Aberdeen Specsavers Hearcare Limited | Wholesale & retail | 2013 |
| Aberdeen Specsavers Limited | Wholesale & retail | 1989 |
| Aberdeen Visionplus Limited | Wholesale & retail | 1993 |
| Abergavenny Specsavers Limited | Wholesale & retail | 1991 |
| Abergavenny Visionplus Limited | Wholesale & retail | 1994 |
| Aberystwyth Specsavers Hearcare Limited | Wholesale & retail | 2013 |
| Aberystwyth Specsavers Limited | Wholesale & retail | 2001 |
| Abingdon Specsavers Hearcare Limited | Wholesale & retail | 2025 |
| Abisglowhut Ltd | Wholesale & retail | 2023 |
| Able Solutions (UK) Limited | Information & communication | 2000 |
| About Health Limited | Professional & scientific | 2008 |
| Abow Property Ltd | Real estate | 2022 |
| ABR Talent Limited | Administrative & support | 2019 |
| ABS (Hampshire) Ltd | Construction | 2026 |
| ABS Property Holdings Limited | Financial services | 2019 |
| Abshot Housing Solutions Ltd | Professional & scientific | 2024 |
| Absolute Air Limited | Manufacturing | 2003 |