| Altrua Care Ltd | Health & social care | 2024 |
| Altruistic Innovations Limited | Information & communication | 2020 |
| Alturra Ltd | Professional & scientific | 2026 |
| ALU & Glass Services Limited | Manufacturing | 2026 |
| Aluka Tech Ltd | Other services | 2023 |
| Alum Group Limited | Real estate | 2016 |
| Aluminium Gates Ireland Ltd | Wholesale & retail | 2025 |
| Alura Bar and Bistro Limited | Hospitality | 2026 |
| ALV Properties Ltd. | Construction | 2001 |
| Alvaro Care Limited | Professional & scientific | 2018 |
| Alvp Ltd | Construction | 2024 |
| ALW Ltd | Manufacturing | 2021 |
| Always Below Ltd | Wholesale & retail | 2021 |
| Always Ready Tours Limited | Wholesale & retail | 2025 |
| Always Something Ltd | Administrative & support | 2014 |
| Alwin Greyson Photography Limited | Professional & scientific | 2004 |
| Alyeo Company Ltd | Health & social care | 2022 |
| Alygance Ltd | Professional & scientific | 2024 |
| Alyson Charles Limited | Arts & recreation | 1995 |
| AM Abbey Travel Ltd | Transport & logistics | 2026 |
| AM Building Services (Yorkshire) Ltd | Construction | 2013 |
| AM Building Services Limited | Wholesale & retail | 2004 |
| AM Construction & Brickwork Limited | Construction | 2026 |
| AM Dining Co Ltd | Hospitality | 2025 |
| AM Executive Travel and Transfers Ltd | Transport & logistics | 2025 |
| AM Fitness (Yorkshire) Limited | Arts & recreation | 2018 |
| AM Greener Gardens Limited | Administrative & support | 2025 |
| AM Magnets (UK) Limited | Extraterritorial | 2002 |
| AM Medcare LLP | | 2015 |
| AM Music Management Ltd | Professional & scientific | 2024 |
| AM News Abbeydale Limited | Wholesale & retail | 2020 |
| AM Pearson Holdings Limited | Financial services | 2025 |
| AM Premier Ltd | Wholesale & retail | 2020 |
| AM Quality Services (PVT) Ltd | Administrative & support | 2024 |
| AM Wells Property Limited | Real estate | 2015 |
| AM Wheels NW Ltd | Wholesale & retail | 2026 |
| AM10 (Lettings) Ltd | Real estate | 2023 |
| AM10 Ltd | Construction | 2016 |
| AMA Financial Consultancy Services Limited | Professional & scientific | 2017 |
| Amaans House of Fashion Limited | Wholesale & retail | 2013 |
| Amaara 313 Ltd | Hospitality | 2022 |
| Amaara Estates Ltd | Households | 2026 |
| Amac Property Ltd | Real estate | 2020 |
| Amala Cloud Solutions Ltd | Information & communication | 2024 |
| Amalfi Slices Ltd | Wholesale & retail | 2026 |
| Aman H Ltd | Financial services | 2021 |
| Aman Honey Ltd | Wholesale & retail | 2025 |
| Amana SU Limited | Wholesale & retail | 2022 |
| Amanah Care Agency Ltd | Health & social care | 2025 |
| Amanah Seds Limited | Public administration | 2023 |
| Amanat Global Ltd | Wholesale & retail | 2025 |
| Amanda Barker Limited | Other services | 2016 |
| Amanda Developments Ltd | Real estate | 2023 |
| Amanda Randle Ltd | Other services | 2023 |
| Amanuel Logistics Ltd | Transport & logistics | 2024 |
| Amaral and Ferreira Limited | Hospitality | 2003 |
| Amaras Beauty Limited | Other services | 2025 |
| Amari Homes Limited | Construction | 2016 |
| Amarkhil Trading Limited | Administrative & support | 2017 |
| Amarsthetics Limited | Health & social care | 2019 |
| Amasol Ltd | Wholesale & retail | 2023 |
| Amax Building Consultancy Limited | Professional & scientific | 2014 |
| Amazed by Shine Cleaning Service Ltd | Administrative & support | 2025 |
| Amazing Hands Care Ltd | Administrative & support | 2020 |
| Amazing Loft Conversions Ltd | Construction | 2019 |
| Amazing Shopfronts Ltd | Manufacturing | 2023 |
| Amazing Space Conversions Ltd | Construction | 2019 |
| Amazon Element Ltd | Wholesale & retail | 2025 |
| Amazon Organic Academy Ltd | Professional & scientific | 2024 |
| Amazon Savers | Administrative & support | 2012 |
| Amazona Properties Limited | Real estate | 2021 |
| AMB Health and Safety Limited | Professional & scientific | 2018 |
| Amb-Give Hope Humanitarian Foundation | Education | 2020 |
| Ambar Climb Ltd | Professional & scientific | 2018 |
| Ambassador Motor Company Limited | Transport & logistics | 1992 |
| Ambassador Repair Centre Limited | Wholesale & retail | 2008 |
| Ambel Ltd | Professional & scientific | 2005 |
| Amber 27 Ltd | Real estate | 2024 |
| Amber Hotels Limited | Hospitality | 2007 |
| Amber Install Ltd | Construction | 2020 |
| Amber Leaf Trading Ltd | Wholesale & retail | 2019 |
| Amber Properties SW Limited | Construction | 2015 |
| Amber Property Holdings Limited | Real estate | 2021 |
| Amber Traders Ltd | Wholesale & retail | 2024 |
| Amberdene Accountancy Limited | Professional & scientific | 2016 |
| Ambergate Assets Ltd | Real estate | 2019 |
| Amberjack Groundworks Ltd | Professional & scientific | 2019 |
| Ambertina Capital Limited | Financial services | 2025 |
| Ambi-Heat Hvac Ltd | Construction | 2019 |
| Ambi-Heat Industrial & Commercial Heating Ltd | Extraterritorial | 2022 |
| Ambiance (Accountants) Limited | Professional & scientific | 2020 |
| Ambition Unlimited CIC | Education | 2019 |
| Ambitious Results Ltd | Education | 2022 |
| Ambr Consultancy Ltd | Professional & scientific | 2025 |
| Ambre Ltd | Wholesale & retail | 2026 |
| Ambro Photography Ltd | Professional & scientific | 2023 |
| Ambrosial Bakes Ltd | Wholesale & retail | 2025 |
| Ambulo Cafes Limited | Hospitality | 2018 |
| Ambustio Limited | Professional & scientific | 2017 |
| Ambz Collection Ltd | Wholesale & retail | 2026 |