| Arden Fabrications Ltd | Real estate | 1999 |
| Arden Fields Equestrian Limited | Agriculture & fishing | 2004 |
| Arden Gates Ltd | Manufacturing | 2003 |
| Arden Hexan Investments Limited | Real estate | 2016 |
| Arden Landscapes Ltd | Administrative & support | 2024 |
| Arden MAT Services Ltd | Education | 2009 |
| Arden Metals Holdings Ltd | Financial services | 2024 |
| Arden Multi Academy Trust | Education | 2010 |
| Arden Oak Management Company Limited | Households | 2004 |
| Arden Occupational Health Limited | Health & social care | 2021 |
| Arden Perception Ltd | Information & communication | 2024 |
| Arden Photonics Ltd | Manufacturing | 2001 |
| Arden Print Limited | Manufacturing | 2015 |
| Arden Printing and Embroidery Ltd | Manufacturing | 2020 |
| Arden Properties (Dorridge) Ltd | Real estate | 2021 |
| Arden Real Estates Limited | Real estate | 2023 |
| Arden Resourcing Limited | Administrative & support | 2011 |
| Arden Tree Surgery Limited | Agriculture & fishing | 2001 |
| Arden Ultraviolet Limited | Other services | 2024 |
| Arden Vale Gardening Ltd | Administrative & support | 2021 |
| Arden View Management Company Limited | Real estate | 2024 |
| Ardencote Estates Limited | Real estate | 2012 |
| Ardendane Ltd | Real estate | 2013 |
| Ardenoak Consulting Limited | Professional & scientific | 2010 |
| Ardenstone Investments Limited | Real estate | 2025 |
| Ardenvale Limited | Construction | 2015 |
| Arena GEO Limited | Professional & scientific | 2018 |
| Arena Sports LAB Ltd | Health & social care | 2026 |
| Arex International Ltd | Wholesale & retail | 2025 |
| Argada Ltd | Real estate | 2023 |
| Argent Wealth Limited | Financial services | 2009 |
| Argmax Ltd | Information & communication | 2024 |
| Argon Securities Limited | Real estate | 1997 |
| Argraig Limited | Real estate | 2022 |
| ARH Sales Consultancy Ltd | Administrative & support | 2021 |
| ARI Investment Management Limited | Real estate | 2026 |
| ARI Medical Limited | Health & social care | 2018 |
| Aria Aesthetics Ltd | Other services | 2024 |
| Arianty Holdings Limited | Financial services | 2000 |
| Arianty NO. 1 PLC | Financial services | 2000 |
| Arielle Property Ltd | Real estate | 2026 |
| Arigna Heights Limited | Construction | 2021 |
| Arinola Management Services Ltd | Real estate | 2016 |
| Arise & Thrive Ltd | Information & communication | 2025 |
| Arise Primecare Services Ltd | Health & social care | 2017 |
| Arizon Properties Limited | Real estate | 2023 |
| Arizona Properties (Ongar) Limited | Hospitality | 1995 |
| Arjai Ltd | Real estate | 2019 |
| ARK Autocentres Limited | Wholesale & retail | 2024 |
| ARK Automation Limited | Information & communication | 2017 |
| ARK Professional Solutions Ltd | Professional & scientific | 2013 |
| ARK Projects Consultancy Limited | Professional & scientific | 1995 |
| Arkatim Limited | Arts & recreation | 2010 |
| Arks (Midlands) Limited | Real estate | 2011 |
| Arks Global Ltd | Wholesale & retail | 2014 |
| Arkstone Ltd | Real estate | 2023 |
| Arksure LLP | | 2005 |
| ARL Contractors Ltd | Construction | 2020 |
| Arlington Way Limited | Real estate | 2010 |
| ARM Real Estate Ltd | Real estate | 2019 |
| Armada Fire Prevention Limited | Administrative & support | 2019 |
| Armada Technical Authors Ltd | Information & communication | 2014 |
| Armais Estates Limited | Real estate | 2001 |
| Armed & Advised Limited | Financial services | 2014 |
| Armk Ltd | Real estate | 2022 |
| Arnold Nexus Investments Limited | Real estate | 2024 |
| ARO Construction Ltd | Construction | 2020 |
| Aroma Widney Road Ltd | Hospitality | 2019 |
| Aron Properties Limited | Households | 2011 |
| Aronm Limited | Health & social care | 2016 |
| Aronz Trading Limited | Wholesale & retail | 2022 |
| Arora Medical Education Limited | Education | 2016 |
| Arora Portfolio Ltd | Real estate | 2018 |
| Arose Properties Limited | Real estate | 2025 |
| ARR Advisory Limited | Financial services | 2026 |
| Art at the Heart C.I.C. | Education | 2016 |
| Art at the Heart of Learning Ltd | Wholesale & retail | 2024 |
| Artbella Properties Limited | Real estate | 2016 |
| Artemis Health Ltd | Education | 2023 |
| Arthian Estates Limited | Real estate | 2025 |
| Arthian Holdings Limited | Real estate | 2025 |
| Arthur John Charles & SON Limited | Manufacturing | 2007 |
| Artico Hair Limited | Other services | 2008 |
| Artifex Interior Systems Limited | Manufacturing | 2005 |
| Artisan Information Technology Limited | Administrative & support | 2000 |
| Artisan Park Limited | Professional & scientific | 2012 |
| Artvise Ltd | Wholesale & retail | 2020 |
| Arusur Ltd | Real estate | 2022 |
| Arvo Solutions Ltd | Professional & scientific | 2020 |
| Arya Rose Finance Ltd | Professional & scientific | 2022 |
| Arya Rose Ltd | Real estate | 2021 |
| Aryaninfo Limited | Information & communication | 2015 |
| Aryas Consulting Limited | Information & communication | 2025 |
| Arycs Limited | Real estate | 2025 |
| AS C4RS Ltd | Wholesale & retail | 2021 |
| AS Medical Consulting Limited | Health & social care | 2026 |
| ASA Express Limited | Transport & logistics | 2015 |
| Asad Social Media Ltd | Information & communication | 2019 |
| Asbpro Asbestos Services Ltd | Construction | 2020 |
| ASC Enterprise Limited | Information & communication | 1998 |