| ALN 1986 Ltd | Transport & logistics | 2019 |
| Aloha Cleaning Services Limited | Administrative & support | 2023 |
| ALP Life Ltd | Wholesale & retail | 2026 |
| Alpha & Co Motors Ltd | Wholesale & retail | 2024 |
| Alpha Church Limited | Other services | 2020 |
| Alpha Developers Ltd | Wholesale & retail | 2025 |
| Alpha House Calderdale | Hospitality | 2008 |
| Alpha Prestige Automotive Ltd | Wholesale & retail | 2024 |
| Alpine Blue Ltd | Professional & scientific | 2015 |
| Alpine Edge SKI Ltd | Education | 2025 |
| Alpine Roofing & Maintenance Ltd | Construction | 2008 |
| ALS Support Ltd | Administrative & support | 2010 |
| Altav Property Services Limited | Other services | 2014 |
| Alternative Floors Limited | Construction | 2018 |
| Altitude Limited | Information & communication | 2018 |
| Altura Systems Ltd | Information & communication | 2026 |
| Alu-Fast Limited | Manufacturing | 2024 |
| Alui (FM) Limited | | 2009 |
| Alzenterprises Ltd | Wholesale & retail | 2026 |
| AM Legal Ltd | Professional & scientific | 2015 |
| AM Legal Properties Ltd | Real estate | 2025 |
| AM PM Properties (HX) Ltd | Real estate | 2015 |
| AMA Digital Ltd | Education | 2025 |
| Amaan Construction Ltd | Construction | 2017 |
| Amanda Dalby Funeral Services Ltd | Other services | 2014 |
| Amanda Dalby Property Services Ltd | Real estate | 2010 |
| Amanda Settle Ltd | Health & social care | 2021 |
| Amani Optical Limited | Health & social care | 2023 |
| Amatey Limited | Professional & scientific | 2012 |
| Amben Ltd | Administrative & support | 2026 |
| Amber Dickinson Limited | Health & social care | 2018 |
| Ambler Mills Limited | Construction | 2018 |
| Ambler Training Limited | Real estate | 2015 |
| AMC HK Properties Ltd | Households | 2025 |
| AMF Bodystyling Ltd | Wholesale & retail | 2020 |
| Amhs Independent Limited | Professional & scientific | 2015 |
| Amis Engineering Services Ltd | Manufacturing | 2015 |
| AMJ Properties Management Limited | Real estate | 2025 |
| AMJ UK Holding Limited | Financial services | 2025 |
| AMK Consultants Private Limited | Health & social care | 2025 |
| AML FF Holdings Ltd | Financial services | 2025 |
| AML Seating Ltd | Manufacturing | 2012 |
| Ammans Fast Food Ltd | Hospitality | 2022 |
| Ammar Carpets Ltd | Other services | 2025 |
| AMMONITE199 Limited | Hospitality | 2024 |
| Amms Transport Ltd | Transport & logistics | 2021 |
| AMO Barber Limited | Other services | 2024 |
| Amorefinds Ltd | Wholesale & retail | 2025 |
| Ampfuel Ltd | Wholesale & retail | 2025 |
| Amplify AV Limited | Wholesale & retail | 2024 |
| Amrns Limited | Transport & logistics | 2025 |
| Amroha Limited | Health & social care | 2021 |
| AMS Restaurant Ltd | Hospitality | 2024 |
| Amtec Engineering Limited | Manufacturing | 2004 |
| Amtul Aziz Ltd | Wholesale & retail | 2026 |
| AMY HOW Limited | Administrative & support | 2019 |
| Amzarhealthcare Ltd | Health & social care | 2025 |
| AN & Shan Ltd | Transport & logistics | 2020 |
| Analog Rfic Ltd | Professional & scientific | 2018 |
| Anchor Construction Group Ltd | Construction | 2024 |
| Andaman Group Ltd | Water & waste | 2023 |
| Andani Financial Solutions Limited | Administrative & support | 2016 |
| Andania Civil Engineering Services Ltd. | Water & waste | 2001 |
| Andie Ltd | Other services | 2019 |
| Andrew Dawson PT Ltd | Other services | 2013 |
| Andrew Greenwood Electrical Limited | Construction | 2019 |
| Andrew Rice Sales Ltd | Wholesale & retail | 2009 |
| Andrew Robertshaw Physiotherapy Ltd | Health & social care | 2014 |
| Andy Denton Joinery Limited | Construction | 2021 |
| Andy Finnell Transport Ltd | Transport & logistics | 2010 |
| Andy Flynn Travel Counsellor Ltd | Administrative & support | 2025 |
| Andy Mckean Builders Ltd | Construction | 2025 |
| Andy Nudds Limited | Other services | 2023 |
| Andys MAN Club Limited | Other services | 2017 |
| Angel Martin Limited | Professional & scientific | 2012 |
| Angel Staffing Ltd | Professional & scientific | 2022 |
| Angelcare Funeral Services Limited | Other services | 2023 |
| Angelcare UK Ltd | Real estate | 2003 |
| Angelides Property Holdings Limited | Real estate | 2022 |
| Anglesea Shores Ltd | Wholesale & retail | 2024 |
| ANH Electrical Ltd | Construction | 2017 |
| ANIMON34 Ltd | Health & social care | 2020 |
| Anis Logistics Ltd | Transport & logistics | 2021 |
| Anish Properties Ltd | Real estate | 2017 |
| Annabel's Dance Collective Ltd | Education | 2024 |
| Another Sunny Afternoon Ltd | Extraterritorial | 2023 |
| Anscars Limited | Administrative & support | 2024 |
| ANT Home Improvements & Property Repairs Limited | Construction | 2018 |
| Anther Limited | Health & social care | 2014 |
| Anthurium Wanderlust Ltd | Wholesale & retail | 2025 |
| Anytime Couriers (UK) Limited | Transport & logistics | 2006 |
| Apartments One Ltd | Hospitality | 2026 |
| Apei UK Limited | Extraterritorial | 2003 |
| Apex ES Ltd | Construction | 2026 |
| Apex Extensions Ltd | Construction | 2026 |
| Apex Imaging Ltd | Health & social care | 2016 |
| Apex(Halifax) Ltd | Wholesale & retail | 2020 |
| Apexion Horizons Ltd | Wholesale & retail | 2025 |
| Apgl Limited | Arts & recreation | 2024 |
| APH Elixir Hscc Ltd | Wholesale & retail | 2012 |