| Armitage Motor Movers Ltd | Transport & logistics | 2026 |
| Armley Food Centre Ltd | Wholesale & retail | 2020 |
| Armolo Ltd | Hospitality | 2025 |
| Armsford Logistics Ltd. | Transport & logistics | 2024 |
| Armstrong Ecology Ltd | Professional & scientific | 2018 |
| Armstrotech Ltd | Manufacturing | 2021 |
| Arnip Limited | Education | 2025 |
| Arnold & SON DRY Goods Limited | Wholesale & retail | 2018 |
| Arnold and Graham Jewellers Ltd | Manufacturing | 2020 |
| Arnold Laver & Company Limited | Professional & scientific | 2023 |
| Arnold Magnetic Technologies Limited | Manufacturing | 2000 |
| Arnold Magnetic Technologies UK Limited | Professional & scientific | 2004 |
| Arnold Magnetic Technologies UK Partnership, LP | | 2005 |
| Arnold Wragg Limited | Manufacturing | 2004 |
| Arnolds Confectioners Ltd | Manufacturing | 2012 |
| ARO Carwash Ltd | Administrative & support | 2021 |
| Arolker Dental Ltd | Administrative & support | 2022 |
| Aroluchi Ville Ltd | Hospitality | 2023 |
| Aroma Holiday Ltd | Manufacturing | 2014 |
| Aromates Limited | Information & communication | 2018 |
| Arona Enterprises Limited | Administrative & support | 2014 |
| Arooj Mega Buffet Restaurant Limited | Hospitality | 2018 |
| Aroon Jawaid Ltd | Wholesale & retail | 2020 |
| Aroos Lens Limited | Professional & scientific | 2025 |
| Aroos Privacy Events Ltd | Other services | 2025 |
| Arouet Ltd | Wholesale & retail | 2023 |
| Around and About Bars Ltd | Hospitality | 2023 |
| ARP Medical Ltd | Health & social care | 2024 |
| ARP Research Ltd | Professional & scientific | 2010 |
| Arquella Ltd | Wholesale & retail | 2018 |
| Arrandale Limited | Real estate | 2003 |
| Array of Bytes Limited | Information & communication | 2015 |
| Arraysolution Limited | Information & communication | 2023 |
| Arrh Properties Limited | Real estate | 2022 |
| Arrow Removals Limited | Transport & logistics | 2025 |
| Arrow Van Racking Systems Ltd | Other services | 2020 |
| Arrows Basketball Club CIC | Education | 2023 |
| Arry Enterprise Ltd | Construction | 2025 |
| Arsalan Hussain Ltd | Professional & scientific | 2024 |
| Arseniespeed Ltd | Transport & logistics | 2025 |
| Arshad Holdings Group Ltd | Financial services | 2025 |
| Arshad Textiles Ltd | Wholesale & retail | 2011 |
| Arshan Property Services Ltd | Construction | 2019 |
| Arslan & Aljoudeh Limited | Health & social care | 2014 |
| Arslans Barber Shop Limited | Other services | 2024 |
| Art Dental Studio Limited | Health & social care | 2013 |
| Art in Concrete Ltd | Construction | 2026 |
| Art of Spice Ltd | Hospitality | 2012 |
| Artan Music Limited | Information & communication | 2019 |
| Artbag Studio Ltd | Arts & recreation | 2017 |
| Artcon Contracts Ltd | Construction | 2010 |
| Artcraft Design and Print Ltd | Administrative & support | 2017 |
| Arteamis Ltd | Wholesale & retail | 2022 |
| Artery Digital Trust Ltd | Financial services | 2025 |
| Artery Media Ltd | Information & communication | 2004 |
| Artful Aura Makeup Limited | Manufacturing | 2025 |
| Arthea Consulting Engineers Ltd | Professional & scientific | 2025 |
| Arthington Buildings Management Company Limited | Households | 2015 |
| Arthrex Limited | Wholesale & retail | 1996 |
| Arthur Paige Publishing Ltd | Health & social care | 2015 |
| Arthur Shirt and Company Limited | Other services | 2021 |
| Arthur Stanley Limited | Wholesale & retail | 2016 |
| Arthurs Aggregates Limited | Water & waste | 2018 |
| Arthurs Metal Recycling Limited | Water & waste | 2018 |
| Arthurs Skips Holdings Limited | Financial services | 2023 |
| Arthurs Skips Limited | Water & waste | 2001 |
| Arthurs Waste Management Limited | Water & waste | 2011 |
| Articulate Sports Ltd | Financial services | 2024 |
| Artificial Grass Sheffield Limited | Administrative & support | 2026 |
| Artificial Grass Solution Limited | Administrative & support | 2026 |
| Artificial Intelligence Solutions & Services Ltd | Information & communication | 2025 |
| Artifkov Limited | Wholesale & retail | 2024 |
| Artin Hospitality Ltd | Hospitality | 2024 |
| Artin Pitta Ltd | Hospitality | 2024 |
| Artindsgn Ltd | Extraterritorial | 2012 |
| Artiphex Limited | Information & communication | 2010 |
| Artisan Construction EA Limited | Construction | 2021 |
| Artisan Software Ltd | Information & communication | 2026 |
| Artistes in Hair Limited | Other services | 2015 |
| Artistries Limited | Arts & recreation | 2004 |
| Artius Plumbing & Heating Limited | Construction | 2023 |
| Artos Munitorum Limited | Wholesale & retail | 2023 |
| Artpic Framing Ltd | Wholesale & retail | 2021 |
| Arts Cleaning Company Ltd | Administrative & support | 2018 |
| Arts in the Right Place CIC | Arts & recreation | 2024 |
| Arts Space Ltd | Real estate | 2019 |
| Arts Transform Community Interest Company | Health & social care | 2018 |
| Artumi Systems Limited | Information & communication | 2013 |
| Arturo Golf Ltd | Arts & recreation | 2025 |
| Artworks R Active Limited | Arts & recreation | 2014 |
| Arty Properties Limited | Real estate | 2010 |
| Arundel Bespoke Kitchens & Interiors Limited | Construction | 2014 |
| Arundel Motors Limited | Transport & logistics | 1934 |
| Arundel Stainless Ware Limited | Manufacturing | 1963 |
| Arundelgate Limited | Real estate | 2013 |
| Arvi Services Limited | Other services | 2025 |
| Arvola Limited | Wholesale & retail | 2025 |
| ARW Building Services Ltd | Construction | 2009 |
| ARW Properties Limited | Real estate | 2020 |
| Arwa Haulage Ltd | Transport & logistics | 2019 |