| Aram Travel Ltd | Administrative & support | 2023 |
| Aran Property Investment Ltd | Real estate | 2020 |
| Aran Property Limited | Real estate | 2011 |
| Aranya's Super Store Ltd | Wholesale & retail | 2021 |
| Aras & Nehir Ltd | Hospitality | 2018 |
| Arati Limited | Real estate | 2001 |
| Arbeiters Ltd | Wholesale & retail | 2023 |
| Arblink Ltd | Information & communication | 2025 |
| Arbomain Ltd | Real estate | 2022 |
| Arboretum Records Limited | Information & communication | 2020 |
| Arboretum SL Limited | Real estate | 2018 |
| Arborex Tree Specialists Ltd | Agriculture & fishing | 2017 |
| Arbre Designs Limited | Professional & scientific | 2025 |
| Arby Ltd | Construction | 2022 |
| ARC (Nottm) Ltd | Wholesale & retail | 2008 |
| ARC Alpha Properties Ltd | Real estate | 2023 |
| ARC Build Group Limited | Financial services | 2015 |
| ARC Building Consultancy Limited | Professional & scientific | 2010 |
| ARC Cinema Ltd | Information & communication | 2019 |
| ARC Complete Building Services Ltd | Construction | 2013 |
| ARC Health & Safety Consultants LLP | | 2013 |
| ARC Health & Safety Services Ltd | Professional & scientific | 2013 |
| ARC Property Services Partnership Ltd | Construction | 2016 |
| ARC Renovations Ltd | Construction | 2026 |
| ARC Retail Design & Development Ltd | Professional & scientific | 2024 |
| ARC Solutions (Midlands) Ltd | Construction | 2024 |
| ARC Sound Limited | Information & communication | 2008 |
| ARC UK Holdings Limited | Financial services | 2015 |
| ARC Vantage Limited | Construction | 2016 |
| Arcadia Projects Ltd | Construction | 2023 |
| Arcadia Signs Ltd | Other services | 2021 |
| Arcaid Investments Limited | Professional & scientific | 2020 |
| Arcaidium Ltd | Professional & scientific | 2023 |
| Arcam Transport Ltd | Transport & logistics | 2025 |
| Arcasim Ltd | Health & social care | 2021 |
| Arcasim Property Ltd | Real estate | 2023 |
| Arcds (London) Limited | Professional & scientific | 2023 |
| Arcdsuk Limited | Professional & scientific | 2021 |
| Arcemea Ltd | Households | 2024 |
| Arch & Co Properties Ltd | Real estate | 2026 |
| Arch Construction and Architecture Ltd | Construction | 2024 |
| Arch Hive Design Ltd | Professional & scientific | 2018 |
| Archa Services Ltd | Administrative & support | 2016 |
| Archer Accident Group Ltd | Administrative & support | 2018 |
| Archer Flooring Limited | Construction | 2008 |
| Archer Group Holdings Limited | Professional & scientific | 2022 |
| Archer House Residence Ltd | Construction | 2018 |
| Archer Solutions Limited | Transport & logistics | 2009 |
| Archerman Limited | Professional & scientific | 1996 |
| Archers of Colwick Limited | Manufacturing | 1998 |
| Archers Roofing Services Ltd | Construction | 2014 |
| Archery Retail Ltd | Wholesale & retail | 2026 |
| Archerytemplar Ltd | Manufacturing | 2025 |
| Archeva Limited | Administrative & support | 2025 |
| Archie Homes Ltd | Real estate | 2026 |
| Archie Johnson Racing Limited | Arts & recreation | 2023 |
| Archie Newbold Limited | Construction | 2009 |
| Archility Digital Ltd | Information & communication | 2016 |
| Archimedia Accounts Ltd | Professional & scientific | 2015 |
| Archimore Ltd | Professional & scientific | 2022 |
| Archiselect Ltd | Wholesale & retail | 2013 |
| Architectural Timber Solutions Ltd | Construction | 2007 |
| Architecture North Ltd | Professional & scientific | 2018 |
| Archoldingsuk Limited | Financial services | 2024 |
| Archrobbat Ltd | Professional & scientific | 2025 |
| Archway Learning Trust | Education | 2011 |
| Archway Nursery Limited | Education | 2017 |
| Arclotec Ltd | Information & communication | 2026 |
| Arcomed(Uk) | | 1990 |
| Arcono Brighton Ltd | Real estate | 2022 |
| Arcono Developments Ltd | Real estate | 2022 |
| Arcono Lewes Limited | Construction | 2024 |
| Arcono Ltd | Real estate | 2016 |
| Arcono Woodingdean Ltd | Construction | 2022 |
| Arcoth Limited | Health & social care | 2023 |
| Arcspace (Nottingham) Limited | Real estate | 2023 |
| Arcstryke Limited | Wholesale & retail | 2025 |
| Arctic Enterprises Limited | Wholesale & retail | 2016 |
| Arctic Fish Bar Cotswolds Limited | Hospitality | 2025 |
| Arctic Limited | Other services | 2007 |
| Arctic Penguin Limited | Professional & scientific | 2020 |
| Arctic Software Development Limited | Information & communication | 2015 |
| Arctic Software Ltd | Information & communication | 2024 |
| Arcturus Digital Consulting Limited | Information & communication | 2023 |
| ARD Decor Ltd | Construction | 2024 |
| ARD Righ Limited | Professional & scientific | 1996 |
| Ardas Properties Ltd | Real estate | 2023 |
| Ardea Technologies Ltd | Information & communication | 2026 |
| Arden 2 Limited | Wholesale & retail | 2013 |
| Arden Aylesford Limited | Professional & scientific | 2018 |
| Arden Information Technology Limited | Information & communication | 2003 |
| Arden Maidstone Limited | Wholesale & retail | 2009 |
| Arden Partnership (Derby) Holdings Limited | Health & social care | 2007 |
| Arden Partnership (Derby) Limited | Health & social care | 2007 |
| Arden Partnership (Leicester) Holdings Limited | Health & social care | 2007 |
| Arden Partnership (Leicester) Limited | Health & social care | 2007 |
| Arden Partnership (Lincolnshire) Holdings Limited | Health & social care | 2006 |
| Arden Partnership (Lincolnshire) Limited | Health & social care | 2006 |
| Arden Tunbridge Wells Limited | Wholesale & retail | 2020 |
| Arden World Media UK Limited | Information & communication | 2021 |