| Anthriscus Vulgare Ltd | Information & communication | 2024 |
| Antoinette Hamilton Aesthetics Ltd | Health & social care | 2020 |
| Anton Benson Productions Limited | Information & communication | 2014 |
| Antony Bennett Holdings Limited | Financial services | 2012 |
| Antwerp Holdings Limited | Extraterritorial | 2018 |
| Anunzs Limited | Wholesale & retail | 2026 |
| ANY Plant Hire Ltd | Administrative & support | 2022 |
| Anything Legal Limited | Professional & scientific | 2010 |
| Anytime Express Transport Limited | Transport & logistics | 2019 |
| Apadana Innovations Limited | Professional & scientific | 2015 |
| Apex Apparel NW Ltd | Wholesale & retail | 2021 |
| Apex Construction (NW) Ltd | Construction | 2019 |
| Apex Control Systems Ltd | Professional & scientific | 2026 |
| Apex Leasing Limited | Transport & logistics | 2026 |
| Apex Properties NW Ltd | Construction | 2021 |
| Apex Protect Security Group Limited | Administrative & support | 2025 |
| APJ Consulting Ltd | Professional & scientific | 2022 |
| Apna Indigo Ltd | Hospitality | 2023 |
| Apois Integrated Limited | Hospitality | 2026 |
| Apollo Autobodies Ltd | Wholesale & retail | 2020 |
| Apollo Insurance Brokers Limited | Other services | 1967 |
| Apollo Motor Company Limited | Wholesale & retail | 2018 |
| Apollo MTS Limited | Manufacturing | 2021 |
| Apollo Multi Technical Services Limited | Manufacturing | 2019 |
| Apollo Pharma Ltd | Manufacturing | 2015 |
| Appeal Consulting Limited | Professional & scientific | 2007 |
| Applauz CIC | Arts & recreation | 2024 |
| Appleby Gardens (Management) Limited | Households | 1983 |
| Applied Process Engineering Ltd | Professional & scientific | 2010 |
| Appy Limited | Information & communication | 2018 |
| April Doll Limited | Manufacturing | 2025 |
| Aprilia Italia Ltd | Wholesale & retail | 2023 |
| APT Door Group Limited | Manufacturing | 2026 |
| APT Security Shutters Limited | Manufacturing | 2016 |
| Aqua Alpha HCW Limited | Other services | 2020 |
| Aqua Dogs Bury Ltd | Arts & recreation | 2015 |
| Aqua Services (UK) Limited | Water & waste | 2013 |
| Aqua Tyres Ltd | Wholesale & retail | 2024 |
| Aqua Valve Limited | Manufacturing | 2009 |
| Aquablast Services Limited | Water & waste | 2001 |
| Aquasure UK Limited | Construction | 2007 |
| Aquatech Plumbing & Heating Engineering Ltd | Construction | 2003 |
| AR Consultants NW Limited | Wholesale & retail | 2025 |
| AR Plumbing Heating Construction Company Ltd | Energy | 2019 |
| AR Scott Properties Limited | Real estate | 2017 |
| Araan Hand Car Wash Limited | Administrative & support | 2023 |
| Arabianwallart Ltd | Wholesale & retail | 2025 |
| Arantis Ltd | Professional & scientific | 2025 |
| Arar Property Holdings Ltd | Real estate | 2025 |
| Arax -Bar Ltd | Transport & logistics | 2025 |
| ARB Consulting Services Limited | Information & communication | 2025 |
| Arbaeen Aboards Ltd | Real estate | 2017 |
| Arbin Ltd | Transport & logistics | 2015 |
| Arbo Property Limited | Real estate | 2018 |
| Arcade Club Ltd. | Arts & recreation | 2016 |
| Arcade Club Sales Limited | Arts & recreation | 2016 |
| Arcade Parts U.K. Limited | Wholesale & retail | 2025 |
| Arcem Building Ltd | Construction | 2025 |
| Arch Island Management Company Limited | Households | 2001 |
| Arch Recruitment Solutions Ltd | Administrative & support | 2022 |
| Arcon Limited | Extraterritorial | 2021 |
| Arctic Accounting Limited | Professional & scientific | 2025 |
| Area 06 Limited | Professional & scientific | 2022 |
| Area Chowz Ltd | Hospitality | 2023 |
| Arem AD Ltd | Professional & scientific | 2013 |
| Arem Homes Ltd | Real estate | 2024 |
| Aren Trading Limited | Extraterritorial | 2021 |
| Arena Protective Coatings Limited | Manufacturing | 2000 |
| Argon Engineering Limited | Administrative & support | 2020 |
| Argyle Bespoke Strategies Limited | Professional & scientific | 2025 |
| Arham Consultancy Ltd | Professional & scientific | 2024 |
| Arham Medical Ltd | Health & social care | 2025 |
| Arindy Ltd | Professional & scientific | 2025 |
| Arivu Clinical & Consulting Ltd | Health & social care | 2026 |
| Arizona Crispy Ltd | Hospitality | 2024 |
| ARK Healthcare Social Enterprises Limited | Health & social care | 2014 |
| Arkan Security & Cleaning Services Ltd | Administrative & support | 2022 |
| Arkdrive NW Limited | Transport & logistics | 2012 |
| Arkid Media Limited | Arts & recreation | 2022 |
| ARL Transport Limited | Transport & logistics | 2018 |
| Arley Acorns Childcare Limited | Health & social care | 2019 |
| Armack Construction Ltd | Construction | 2024 |
| Armack Limited | Extraterritorial | 2020 |
| Armada Associates Limited | Extraterritorial | 2020 |
| Armadillo Metal Coatings Ltd | Professional & scientific | 2019 |
| Armco Asbestos Consultants Ltd | Construction | 2014 |
| Arms Motors Ltd | Wholesale & retail | 2026 |
| Arrm Limited | Construction | 2025 |
| Arrow Drop Services Ltd | Transport & logistics | 2024 |
| Arrs Residential Limited | Real estate | 2025 |
| Arshad & Sons Enterprises Ltd | Real estate | 2023 |
| Art Exhibition Textiles Limited | Wholesale & retail | 1999 |
| Art, Life, Technology. Ltd | Information & communication | 2013 |
| Arthroplasty Limited | Health & social care | 2010 |
| Arthur Bradshaw Limited | Construction | 1906 |
| Artura Solutions Limited | Other services | 2017 |
| ARU Properties & Lettings Ltd | Real estate | 2025 |
| Arwh Holdings Limited | Financial services | 2018 |
| Arxium Ltd | Administrative & support | 2026 |
| AS Building Works Ltd | Construction | 2024 |