| Aram Catering Limited | Hospitality | 2023 |
| Aram Construction Services Ltd | Construction | 2022 |
| Aram Shawarma Ltd | Hospitality | 2025 |
| Aram Technology Ltd | Wholesale & retail | 2026 |
| Aramas Law Limited | Professional & scientific | 2019 |
| Aramit Properties Ltd | Real estate | 2020 |
| Aramkao Ltd | Real estate | 2022 |
| Aramofe Global Limited | Wholesale & retail | 2024 |
| Arams Southern | Professional & scientific | 2020 |
| Aramy and Properties Ltd | Real estate | 2025 |
| Arancia Coaching Ltd | Professional & scientific | 2023 |
| Arandelle Limited | Wholesale & retail | 1997 |
| Aranez Services Ltd | Other services | 2012 |
| Arantir Consulting Solution Ltd | Administrative & support | 2021 |
| Araripe Limited | Real estate | 2010 |
| Arashat Limited | Administrative & support | 2019 |
| Aratellus Midco Limited | Financial services | 2024 |
| Araucana Limited | Professional & scientific | 2011 |
| Aray Social Ltd | Information & communication | 2022 |
| Araz Property Services Limited | Real estate | 2026 |
| ARB Commercial Holdings Ltd | Real estate | 2023 |
| ARB Landscaping&Garden Maitenance Ltd | Professional & scientific | 2026 |
| Arbaba Ltd | Wholesale & retail | 2023 |
| Arbat Clad Ltd | Construction | 2024 |
| Arbil Restaurant Limited | Hospitality | 2026 |
| Arbil UK Golden Limited | Real estate | 2016 |
| Arbor Health Limited | Health & social care | 2026 |
| Arborfield Estates Limited | Real estate | 2018 |
| Arboris Ridge Limited | Professional & scientific | 2025 |
| Arbortec Tree Surgery Limited | Agriculture & fishing | 2013 |
| Arbory 1960 Limited | Extraterritorial | 2014 |
| Arbtech Consulting Limited | Agriculture & fishing | 2006 |
| ARC 88 Limited | Professional & scientific | 2023 |
| ARC and Co Lettings Ltd | Real estate | 2025 |
| ARC Appliance Care Ltd | Other services | 2018 |
| ARC Decals Ltd | Manufacturing | 2025 |
| ARC Electrical Contractors Ltd | Construction | 2016 |
| ARC Food Imp-Exp Ltd | Wholesale & retail | 2023 |
| ARC Football Limited | Arts & recreation | 2025 |
| ARC Leadership Ltd | Professional & scientific | 2021 |
| ARC Motors Ltd | Wholesale & retail | 2025 |
| ARC MRB Ltd | Real estate | 2019 |
| ARC Properties and Lettings Ltd | Real estate | 2017 |
| ARC Rentals Ltd | Transport & logistics | 2024 |
| ARC Roofing & Building Contractor Ltd | Construction | 2005 |
| ARC Technology Limited | Information & communication | 1990 |
| ARC Training and Apprenticeships Limited | Extraterritorial | 2014 |
| ARC Trustees Limited | Financial services | 2013 |
| ARC Urban Regeneration Consulting Limited | Professional & scientific | 2010 |
| ARC Vision Monitoring Limited | Information & communication | 2024 |
| Arc-En-Ciel S.A. Ltd. | Wholesale & retail | 2024 |
| Arcade Investments Limited | Real estate | 2018 |
| Arcade.Mall Ltd | Wholesale & retail | 2024 |
| Arcadia (Bolton) Management Company Limited | Households | 2007 |
| Arcadia Accountancy Services Limited | Professional & scientific | 2026 |
| Arcadia Engineering Ltd | Professional & scientific | 2024 |
| Arcadia Flow Ltd | Administrative & support | 2022 |
| Arcadia Glow Ltd | Other services | 2025 |
| Arcadia North Limited | Professional & scientific | 2025 |
| Arcadia Solutions Ltd | Financial services | 2025 |
| Arcadian Lounge Ltd | Hospitality | 2023 |
| Arcaid Group Ltd | Financial services | 2026 |
| Arcamex Developments Limited | Information & communication | 2024 |
| Arcamex Ltd | Information & communication | 2005 |
| Arcams Limited | Water & waste | 2025 |
| Arcane AI Limited | Information & communication | 2026 |
| Arcanum Industries Ltd | Wholesale & retail | 2014 |
| Arcca Ltd | Professional & scientific | 2005 |
| Arcd Architects Ltd | Other services | 2020 |
| Arcelormittal Building Solutions UK Limited | Manufacturing | 2000 |
| Arcendry Ltd | Wholesale & retail | 2025 |
| Arcentury Ltd | Administrative & support | 2016 |
| Arcet Ltd | Information & communication | 2026 |
| Arch & Co Clinic Ltd | Health & social care | 2020 |
| Arch & Co Training Academy Ltd | Education | 2020 |
| Arch Biocides Trustee Limited | Financial services | 2004 |
| Arch Chemicals Products Limited | Financial services | 1970 |
| Arch Chemicals UK Finance | Financial services | 2004 |
| Arch Chemicals UK Holdings Limited | Professional & scientific | 2000 |
| Arch Dental Ltd | Other services | 2019 |
| Arch Holdco Ltd | Financial services | 2024 |
| Arch NO7 Ltd | Hospitality | 2024 |
| Arch of Marcus Ltd | Hospitality | 2025 |
| Arch Planning & Design Ltd | Professional & scientific | 2025 |
| Arch Project Management Limited | Extraterritorial | 2016 |
| Arch Seven Limited | Hospitality | 2025 |
| Arch Timber Protection Limited | Manufacturing | 1946 |
| Arch UK Biocides Limited | Manufacturing | 2003 |
| Arch-Kos Limited Partnership | | 2008 |
| Archacy Ltd | Professional & scientific | 2025 |
| Archai Powertech Ltd | Construction | 2023 |
| Archainify Limited | Information & communication | 2023 |
| Archangel Entertainment Ltd | Information & communication | 2025 |
| Archbrook Medical Ltd | Financial services | 2026 |
| Archcode Limited | Information & communication | 2024 |
| Archcrew Homes Limited | Households | 2025 |
| Archen Ltd | Information & communication | 2023 |
| Archer Brick & Stone Ltd | Construction | 2022 |
| Archer Group Ltd | Real estate | 2025 |
| Archertype Events Limited | Arts & recreation | 2017 |