| Ar&C Properties Ltd | Manufacturing | 2025 |
| AR1 Medical Ltd | Health & social care | 2018 |
| ARA Health Limited | Manufacturing | 2012 |
| ARA Immigration Services Limited | Professional & scientific | 2007 |
| ARA Investigations Limited | Administrative & support | 2025 |
| Araby Court Management Limited | Households | 1993 |
| Aran Cars Ltd | Transport & logistics | 2025 |
| Arasaig Limited | Professional & scientific | 2022 |
| Aratech IT Consulting Limited | Information & communication | 2025 |
| Aravi Enterprise Limited | Hospitality | 2025 |
| ARB Mechanical Engineering Employee Ownership Trustee Limited | Professional & scientific | 2021 |
| ARB Pro Software Limited | Information & communication | 2013 |
| Arbentin Services Limited | Professional & scientific | 2003 |
| Arbis Holdings Limited | Financial services | 2020 |
| Arbormac Arboriculture Ltd | Administrative & support | 2021 |
| ARC Pownall Limited | Administrative & support | 2020 |
| ARC Project Consulting Limited | Professional & scientific | 2021 |
| ARC Projects Property Limited | Real estate | 2025 |
| ARC Southern Ltd | Wholesale & retail | 2013 |
| Arca Collis Ltd | Hospitality | 2025 |
| Arcadian Ecology & Consulting Limited | Professional & scientific | 2016 |
| Arcadian Shepherds Limited | Information & communication | 2003 |
| Arch Property & Developments Ltd | Construction | 2013 |
| Arch Property Management Ltd | Other services | 2010 |
| Arch South Group Ltd | Financial services | 2023 |
| Arch South Ltd | Wholesale & retail | 2019 |
| Archavant Limited | Manufacturing | 2011 |
| Archdent Solutions Ltd | Professional & scientific | 2025 |
| Archer Lighting Ltd | Manufacturing | 2026 |
| Archer Research and Development Limited | Manufacturing | 2025 |
| Archers Recruitment Group Ltd | Administrative & support | 2023 |
| Archetype Express Limited | Wholesale & retail | 2025 |
| Archibald of Chichester Moving & Storage Limited | Professional & scientific | 2008 |
| Archie Hamilton Prestige Cars Limited | Wholesale & retail | 2023 |
| Architech Audit & Compliance Ltd | Information & communication | 2020 |
| Architech Cloud Services Ltd | Information & communication | 1997 |
| Architech Digital Nominees Ltd | Information & communication | 2020 |
| Architech Information Management Ltd | Information & communication | 2013 |
| Architectural Building Concept Designs Limited | Professional & scientific | 2008 |
| Architok UK Ltd | Wholesale & retail | 2024 |
| Arcturus Associates Ltd | Professional & scientific | 2017 |
| ARD Audio Ltd | Professional & scientific | 2019 |
| ARD Landscapes Ltd | Administrative & support | 2025 |
| ARD Rose Consultancy Ltd | Professional & scientific | 2022 |
| Ardlussa Holdings Ltd | Financial services | 2020 |
| Ardmore Gresham Consultancy Ltd | Education | 2019 |
| Ardor Training Ltd | Public administration | 2017 |
| Ardos 3D Rendering Limited | Professional & scientific | 2025 |
| Ardotec Ltd | Administrative & support | 2020 |
| Area Chow Ltd | Hospitality | 2024 |
| Areca Tickets Ltd | Administrative & support | 2013 |
| Arena Business Centres Basingstoke Limited | Extraterritorial | 2020 |
| Arena Business Centres Limited | Real estate | 2002 |
| Arena Farnborough Limited | Real estate | 2014 |
| Arenda Ltd | Hospitality | 2022 |
| Arete Leotards Ltd | Wholesale & retail | 2017 |
| Arethe Directors Services Ltd | Administrative & support | 2006 |
| Areyan Cars Limited | Administrative & support | 2023 |
| Argentum Capital Partners Ltd | Professional & scientific | 2023 |
| Argie’S Cakes & Finger Foods Limited | Manufacturing | 2022 |
| Argo Engineering Solutions Limited | Professional & scientific | 2016 |
| Argo Engineering Trustee Company Limited | Financial services | 2025 |
| Argonaut Property Services Limited | Real estate | 2020 |
| Argus Network Solutions Limited | Information & communication | 2010 |
| Argyll Court Management Company Limited | Households | 2006 |
| ARI Media Limited | Information & communication | 2013 |
| Ari's Hampshire Windscreens Ltd | Wholesale & retail | 2025 |
| Aries Medical Limited | Health & social care | 2013 |
| Arise and Shine Consulting Limited | Health & social care | 2011 |
| Arisecare Ltd | Health & social care | 2018 |
| Arish Grocery Ltd | Wholesale & retail | 2023 |
| Arismore Court Residents Company Limited | Households | 1978 |
| Aristocrat Signs Limited | Administrative & support | 2006 |
| Arix Pharma Ltd | Wholesale & retail | 2025 |
| Ariyashifa Ltd | Wholesale & retail | 2025 |
| Ariza AL Limited | Transport & logistics | 2015 |
| ARJ Accountancy Limited | Professional & scientific | 2010 |
| Arjun IT Consulting Ltd | Information & communication | 2021 |
| ARK Assist & Support Ltd | Information & communication | 2024 |
| ARK Business Intelligence Ltd | Information & communication | 2024 |
| ARK Carpentry & Construction Ltd | Construction | 2017 |
| ARK Maison Limited | Real estate | 2017 |
| ARK Marine Limited | Professional & scientific | 2016 |
| ARK Property Limited | Real estate | 1999 |
| ARK Vision Ltd | Real estate | 2024 |
| Arkaya Energy Limited | Wholesale & retail | 2016 |
| Arkazon Ltd | Wholesale & retail | 2025 |
| Arkham TEK Ltd | Information & communication | 2014 |
| Arkhamsecure Ltd | Wholesale & retail | 2026 |
| Arlico Ltd | Manufacturing | 2013 |
| Arliss Court RTM Company Limited | Households | 2022 |
| Arlo Services Limited | Other services | 2014 |
| Arloash Ltd | Wholesale & retail | 2025 |
| Arlyia Medical Ltd | Health & social care | 2021 |
| Armada Contracting Services Ltd | Construction | 2019 |
| Armani Capital Limited | Wholesale & retail | 2020 |
| Armchair Theatre Ltd | Arts & recreation | 2012 |
| Armeenroya Limited | Health & social care | 2010 |
| Armex Electrical Limited | Construction | 2017 |
| Armfield House Management Company Limited | Households | 2008 |