| Alvington Meadows Management Ltd | Households | 2019 |
| Alwaysolution Ltd | Construction | 2025 |
| ALY Duarte Limited | Administrative & support | 2025 |
| Alya Medical Services Limited | Health & social care | 2013 |
| Alyaan Limited | Construction | 2022 |
| Alyana.F Ltd | Wholesale & retail | 2025 |
| Alzir Ltd | Financial services | 2025 |
| AM & NB Limited | Information & communication | 2019 |
| AM & Sons Halal Meat & Convenience Store Ltd | Transport & logistics | 2004 |
| AM 2 PM Contracting & Construction Limited | Construction | 2024 |
| AM Business Ventures 1 Ltd | Real estate | 2017 |
| AM Ductwork Services Ltd | Construction | 2016 |
| AM Future Consultant Ltd | Education | 2019 |
| AM Kharal Holdings LLP | | 2018 |
| AM Mazeika Limited | Construction | 2017 |
| AM Networking Ltd | Information & communication | 2009 |
| AM Prime Hub Ltd | Wholesale & retail | 2025 |
| AM Properties London Ltd | Financial services | 2020 |
| AM Property Developers Ltd | Real estate | 2025 |
| AM Real Properties Limited | Construction | 2025 |
| AM Security London Ltd | Administrative & support | 2026 |
| AM Softech Limited | Information & communication | 2012 |
| AM UK Trading Limited | Wholesale & retail | 2012 |
| AM Wimpey Ltd | Hospitality | 2019 |
| Am&Hu Limited | Wholesale & retail | 2025 |
| AM2PEU Ltd | Other services | 2012 |
| Am:Pm Events Management Ltd | Hospitality | 2025 |
| AMA Advisors Ltd | Administrative & support | 2024 |
| AMA Carpentry Ltd | Manufacturing | 2026 |
| AMA Contractors Limited | Administrative & support | 2022 |
| AMA Generic Limited | Health & social care | 2002 |
| AMA London Aesthetics Ltd | Other services | 2021 |
| Ama's Organic Ltd | Wholesale & retail | 2025 |
| Amaa Holdings Ltd | Financial services | 2024 |
| Amaa Ltd | Wholesale & retail | 2020 |
| Amaade Limited | Real estate | 2020 |
| Amaaray Limited | Real estate | 2024 |
| Amac Build Limited | Construction | 2023 |
| Amacor Ltd | Construction | 2021 |
| Amadoo Ltd | Wholesale & retail | 2025 |
| Amal Amin Enterprises Ltd | Wholesale & retail | 2025 |
| Amal Relief Ltd | Administrative & support | 2025 |
| Amaltas Traders Limited | Wholesale & retail | 2020 |
| Aman Fashions Ltd | Other services | 2009 |
| Aman Food Group Limited | Hospitality | 2019 |
| Aman Mobile Zone Ltd | Wholesale & retail | 2026 |
| Amana Chauffeur Services Ltd | Transport & logistics | 2023 |
| Amana Property Ltd | Real estate | 2020 |
| Amanah Audio Ltd | Professional & scientific | 2024 |
| Amanah Prestige Limited | Wholesale & retail | 2010 |
| Amanah Prime Ltd | Manufacturing | 2026 |
| Amanda Academy of Piano & Tutoring Ltd | Education | 2025 |
| Amandacare Ltd | Health & social care | 2021 |
| Amani Asan Subway Ltd | Hospitality | 2024 |
| Amankeerat Investments Ltd | Real estate | 2026 |
| Amar Bangla School Ltd | Education | 2023 |
| Amar Beauty London Ltd | Education | 2026 |
| Amar Construction & Windows Ltd | Construction | 2025 |
| Amar J Investments Ltd | Real estate | 2018 |
| Amara Drive Group Ltd | Wholesale & retail | 2026 |
| Amara Events Limited | Arts & recreation | 2023 |
| Amara Promotions Limited | Arts & recreation | 2022 |
| Amarah Ltd | Real estate | 2020 |
| Amariutei Cleaning Ltd | Construction | 2016 |
| Amaroo Limited | Wholesale & retail | 2018 |
| Amarshuns UK Limited | Information & communication | 2009 |
| Amas Interiors Ltd | Construction | 2017 |
| Amathyst Ltd | Information & communication | 2025 |
| Amatu Limited | Health & social care | 2018 |
| Amax Tech Trading Ltd | Wholesale & retail | 2023 |
| Amaya Homes Ltd | Real estate | 2018 |
| Amayra Care Limited | Health & social care | 2024 |
| Amayra Fabrics Ltd | Wholesale & retail | 2026 |
| Amazing Estates Limited | Real estate | 2013 |
| Amazing London Online Limited | Wholesale & retail | 2021 |
| Amazing Market Ltd | Wholesale & retail | 2020 |
| Amazing Wardrobes Ltd | Manufacturing | 2019 |
| Amazingly Simple Accounting Services Ltd | Professional & scientific | 2014 |
| Amazonix Limited | Wholesale & retail | 2026 |
| Amazuco Ltd | Manufacturing | 2024 |
| AMB 786 Property Investment Ltd | Real estate | 2024 |
| AMB Advocates & Accountants Limited | Professional & scientific | 2009 |
| AMB Property Services Ltd | Real estate | 2017 |
| AMB Rail Limited | Construction | 2019 |
| AMB1 Property & Estates Ltd | Real estate | 2017 |
| Amba Randal Limited | Real estate | 2022 |
| Ambasys Technologies Ltd | Information & communication | 2024 |
| Ambdag Limited | Information & communication | 2012 |
| Amber (UK) Ltd | Administrative & support | 2013 |
| Amber Castle Limited | Construction | 2007 |
| Amber Constructions Services Limited | Extraterritorial | 2023 |
| Amber Decorating Limited | Extraterritorial | 2003 |
| Amber Dynamics Limited | Transport & logistics | 2016 |
| Amber Fostering Ltd | Health & social care | 2019 |
| Amber Nest Ltd | Wholesale & retail | 2023 |
| Amber Roofing Services Limited | Extraterritorial | 2006 |
| Amber Wealth Limited | Financial services | 2013 |
| Amber Windows Limited | Construction | 2015 |
| Amberberry Construction Ltd | Construction | 2024 |
| Amberberry Investments Ltd | Real estate | 2020 |