| Angell Mallinder Properties Ltd | Real estate | 2021 |
| Angell Ship Limited | Real estate | 2022 |
| Angelos Thanasis Ltd | Manufacturing | 2023 |
| ANH LE Limited | Other services | 2024 |
| Anila Patel Freelance Design Ltd | Professional & scientific | 2016 |
| Anilex Limited | Professional & scientific | 2016 |
| Anilex Property Limited | Real estate | 2017 |
| Animals at Home (West Leicestershire) Limited | Professional & scientific | 2018 |
| Anisha.Chauhan Limited | Other services | 2026 |
| Anmb Limited | Health & social care | 2013 |
| Annapurna FO Limited | Financial services | 2022 |
| Annapurna Property Holdings Limited | Real estate | 2024 |
| Annapurna Residential (Cabot Mews) Limited | Real estate | 2023 |
| Anns Properties Ltd | Real estate | 2023 |
| Anso Ltd | Hospitality | 2017 |
| Antalya Kitchen Loughborough Ltd | Hospitality | 2025 |
| Anthony James Insurance Brokers Limited | Financial services | 2009 |
| Anthonys Vendings Ltd | Wholesale & retail | 2024 |
| Anti-Ram Raid UK Ltd | Construction | 2010 |
| Antohabi Ltd | Transport & logistics | 2024 |
| Anugraah Ltd | Wholesale & retail | 2019 |
| Anuhill Holdings Ltd | Financial services | 2025 |
| ANV Chem Corp., UK Limited | Wholesale & retail | 2013 |
| Anval Business Consultancy Ltd | Professional & scientific | 2022 |
| Anvanstone Holdings Ltd | Administrative & support | 2023 |
| Anvaya Holdings Ltd | Real estate | 2025 |
| AP Maintenance Services Limited | Manufacturing | 2002 |
| AP Motorway Trade Centre Ltd | Water & waste | 2025 |
| AP Spares Ltd | Wholesale & retail | 2024 |
| AP Thakker Ltd | Health & social care | 2026 |
| Apac Europe Holdings Limited | Financial services | 2019 |
| Apac Group Holdings Ltd | Financial services | 2018 |
| Apac Packaging Limited | Extraterritorial | 2014 |
| APE Events Ltd | Professional & scientific | 2025 |
| APE Marketing Ltd | Professional & scientific | 2022 |
| Apex Autos Limited | Transport & logistics | 2025 |
| Apex Construction UK Group Ltd | Real estate | 2024 |
| Apex Events Services Limited | Wholesale & retail | 2024 |
| Apex Infrastructure Limited | Wholesale & retail | 2024 |
| Apex Joinery & Construction Limited | Construction | 2023 |
| Apex Performance Centre Ltd | Wholesale & retail | 2024 |
| Apex Professional Consulting Ltd | Professional & scientific | 2022 |
| Apex Renewables Group Ltd | Construction | 2024 |
| Apex Social Work Services Limited | Health & social care | 2015 |
| Apex Steam Cleaning Limited | Administrative & support | 2005 |
| Apex Technology Services Limited | Information & communication | 2015 |
| Apex Valeting Ltd | Administrative & support | 2026 |
| Apharo Ltd | Administrative & support | 2024 |
| Aphelops Ltd | Information & communication | 2020 |
| Aphex Systems Limited | Manufacturing | 1992 |
| Aphm Limited | Arts & recreation | 2007 |
| APJ Structures Ltd | Construction | 2026 |
| Aplite Sport Limited | Arts & recreation | 2023 |
| Apna Care Ltd | Health & social care | 2021 |
| Appamore Limited | Information & communication | 2021 |
| Apparent Marketing Limited | Professional & scientific | 2026 |
| Apple & Pear (Woodhouse ) Ltd | Wholesale & retail | 2022 |
| Apple Language Courses Limited | Education | 2012 |
| Appsc Limited | Professional & scientific | 2010 |
| APS (Midlands) Ltd | Professional & scientific | 2014 |
| APW Flooring Limited | Construction | 2025 |
| APW Services (Heating & Plumbing) Limited | Construction | 2010 |
| APX3 Limited | Professional & scientific | 2017 |
| Aqua Visus Ltd | Professional & scientific | 2019 |
| Aquaculture Innovations Limited | Agriculture & fishing | 2021 |
| Aquadry UK Limited | Other services | 2018 |
| Aqualiner Limited | Professional & scientific | 2007 |
| Aquarium-Fish Ltd | Administrative & support | 2014 |
| Aquifer Energy Ltd | Professional & scientific | 2024 |
| Aquila Specialist Housing Ltd | Financial services | 2019 |
| Aquire Personnel Ltd | Administrative & support | 2023 |
| AR & Co Consulting Limited | Education | 2016 |
| AR Retail Hub Limited | Wholesale & retail | 2026 |
| Arapapro Training Limited | Education | 2021 |
| ARC 400H Limited | Arts & recreation | 2023 |
| ARC Fabrics Limited | Manufacturing | 1978 |
| Arcadia Investments Group Limited | Professional & scientific | 2016 |
| Arcelo Design Ltd | Manufacturing | 2023 |
| Arch Sign Build Solutions Limited | Professional & scientific | 2026 |
| Arch/Form Studio Ltd | Professional & scientific | 2022 |
| Archer-Donaldson Limited | Agriculture & fishing | 2025 |
| Archery Mentor Limited | Manufacturing | 2015 |
| Archery Warehouse Direct Limited | Wholesale & retail | 2015 |
| Archiepba Ltd | Information & communication | 2012 |
| Arctpw Limited | Administrative & support | 2024 |
| Ardellia Group Limited | Wholesale & retail | 2025 |
| Ardent Systems Limited | Professional & scientific | 2002 |
| Arena Track and Sports Ltd | Arts & recreation | 2024 |
| Arendelle Limited | Professional & scientific | 2022 |
| ARG Auto Repairs Ltd | Wholesale & retail | 2024 |
| ARG Bodyshop Ltd | Wholesale & retail | 2020 |
| ARG Commercials Ltd | Wholesale & retail | 2019 |
| ARG Property Group Ltd | Real estate | 2025 |
| Argyle Rose Limited | Other services | 2017 |
| Arilan Pyrotechnics Ltd | Wholesale & retail | 2024 |
| Arishabeez Ltd | Wholesale & retail | 2026 |
| Arisure Consultancy Limited | Extraterritorial | 2018 |
| Arisure Limited | Extraterritorial | 2018 |
| Ark-Ed(Uk) Ltd | Education | 2021 |
| Arkham Industries Ltd | Extraterritorial | 2018 |