| ABS Build Limited | Construction | 2021 |
| ABS Friends Ltd | Wholesale & retail | 2024 |
| Absolutely Hair Ltd | Other services | 2004 |
| Acadds (East Anglia) Ltd | Professional & scientific | 2012 |
| Acadelix Talent Ltd | Education | 2025 |
| Academy for Adventure Learning and Well Being Ltd | Education | 2025 |
| Academy for Transformative Leadership Limited | Education | 2024 |
| Acadpath Planning Limited | Information & communication | 2026 |
| Accelerate Bidco Limited | Administrative & support | 2022 |
| Accelerate Holdco Limited | Administrative & support | 2022 |
| Accelerate Logistics Ltd | Transport & logistics | 2024 |
| Accelerate Midco Limited | Administrative & support | 2022 |
| Accelerate Topco Limited | Administrative & support | 2022 |
| Access to Profit Ltd | Financial services | 2008 |
| Accessible Adventure Ltd | Education | 2023 |
| Accofox Ltd | Professional & scientific | 2024 |
| Accommodate Property Management Ltd | Real estate | 2026 |
| Accountancy Accelerator Limited | Professional & scientific | 2025 |
| Acctify Ltd | Professional & scientific | 2025 |
| Accéder Global Ltd. | Information & communication | 2020 |
| Acdc Labs Ltd | Information & communication | 2022 |
| Ace Allstars Ltd | Arts & recreation | 2024 |
| Ace Global Services Limited | Wholesale & retail | 2023 |
| Ace HD Properties Ltd | Real estate | 2023 |
| Ace Media Group Ltd | Information & communication | 2025 |
| Ace Sarhene Group Ltd | Manufacturing | 2023 |
| Ace Travel & Money Transfer Ltd | Administrative & support | 2018 |
| Ace UK IT Ltd | Information & communication | 2013 |
| Ace'D Clothing Limited | Wholesale & retail | 2025 |
| Acer & Camellia Limited | Arts & recreation | 2024 |
| Acer Mortgage Solutions Ltd | Financial services | 2024 |
| Acertine Ltd | Information & communication | 2025 |
| Achieving Greatness Ltd | Information & communication | 2003 |
| Achieving Querencia Limited | Wholesale & retail | 2021 |
| Achill Tyres Ltd. | Wholesale & retail | 1998 |
| Achr Property Ltd | Real estate | 2025 |
| Acia Consulting Ltd | Professional & scientific | 2022 |
| ACL Acquisitions Ltd | Real estate | 2023 |
| Acnet Ltd | Professional & scientific | 2016 |
| Acorn Landscaping (Anglia) Ltd | Administrative & support | 2007 |
| Acorn Prevention Control Solution Limited | Hospitality | 2014 |
| Acorn Tax & Accountancy Limited | Professional & scientific | 2012 |
| Acrehill Estates Ltd | Real estate | 2026 |
| Acropolis Property Solutions Ltd | Construction | 2026 |
| Across the Border CIC | Education | 2025 |
| Acss (SW) Limited | Information & communication | 2017 |
| ACT 3D Limited | Professional & scientific | 2026 |
| Active Outdoors Ltd. | Arts & recreation | 2015 |
| Active Polaris Ltd | Extraterritorial | 2020 |
| Acton Wrap Around Care Ltd | Health & social care | 2022 |
| Acumen Strategic Partners Ltd | Other services | 2019 |
| Acupaq Limited | Extraterritorial | 2016 |
| Acuvis Systems Limited | Wholesale & retail | 2026 |
| ACW Bathrooms and Kitchens Ltd | Construction | 2023 |
| Acws Consultancy Limited | Financial services | 2022 |
| AD Seventy One Ltd | Professional & scientific | 2023 |
| AD Technology Services Ltd | Information & communication | 2024 |
| AD Trailer Hire Ltd | Administrative & support | 2022 |
| ADA Baby Limited | Wholesale & retail | 2021 |
| Adacinbio Ltd | Professional & scientific | 2025 |
| Adal Research Ltd | Information & communication | 2024 |
| Adam & Jamilou Properties Limited | Real estate | 2020 |
| Adam Briffett Advisory Ltd | Professional & scientific | 2025 |
| Adam Haaris Limited | Wholesale & retail | 2023 |
| Adam Jenkins Design Ltd | Administrative & support | 2018 |
| Adam Wood Carpentry & Building Ltd | Manufacturing | 2026 |
| Adam's Aerials Ltd | Wholesale & retail | 2008 |
| Adamantine Group Ltd | Financial services | 2019 |
| Adamelia Ltd | Real estate | 2025 |
| Adamkeepzi Ltd | Wholesale & retail | 2026 |
| Adams Property Holdings Limited | Real estate | 2016 |
| Adapted Accommodation Ltd | Real estate | 2025 |
| Adaptify Talent Solutions Ltd | Information & communication | 2024 |
| Adaptive Trail Ltd | Professional & scientific | 2024 |
| Adaslar Ltd | Hospitality | 2023 |
| Adco Construction Group Limited | Construction | 2021 |
| Adco Construction Ltd | Construction | 2017 |
| Adco Property Solutions Ltd | Construction | 2023 |
| Adcock Holdings Ltd | Real estate | 2024 |
| ADD Nutrition Limited | Wholesale & retail | 2025 |
| Adders Entertainment Group Ltd | Manufacturing | 2024 |
| Addison Consolidated Enterprises Limited | Information & communication | 2021 |
| Adenea Consulting Limited | Professional & scientific | 2009 |
| Adept Safety Management Ltd | Professional & scientific | 2010 |
| Adeptable Ltd | Information & communication | 2022 |
| Adham Optical Ltd | Wholesale & retail | 2021 |
| Adinsight Ltd | Professional & scientific | 2025 |
| Aditiavni Property Limited | Real estate | 2018 |
| Adler Analytics Ltd | Professional & scientific | 2023 |
| Adlo Energy Ltd | Professional & scientific | 2023 |
| ADM Controls Limited | Manufacturing | 2006 |
| ADM Tech Consulting Ltd | Information & communication | 2024 |
| Admark Shipping Solutions Limited | Transport & logistics | 2009 |
| Admin Alchemist Ltd | Administrative & support | 2020 |
| Admin Care Ltd | Administrative & support | 2022 |
| Admin NO. 1 Ltd | Administrative & support | 2019 |
| Admitics Ltd | Information & communication | 2026 |
| Admix Medya Ltd | Information & communication | 2026 |
| Adohu Ltd | Information & communication | 2022 |
| Adonis Global Ltd | Information & communication | 2026 |