| APL Magnetos Ltd | Administrative & support | 2005 |
| APL Windings Limited | Administrative & support | 2007 |
| APM Exel Limited | Information & communication | 2010 |
| Apmpm Ltd | Information & communication | 2012 |
| APO Group Limited | Real estate | 2019 |
| APO People Limited | Real estate | 2020 |
| App Distribution Ltd | Other services | 2013 |
| App Sprout Limited | Information & communication | 2016 |
| Appleshaw Investments Ltd | Financial services | 2021 |
| Appletree Grove (Chinnor) Management Company Limited | Households | 2025 |
| Aprp Ltd | Construction | 2022 |
| Apsham Grange (Topsham) Management Company Limited | Households | 2021 |
| Apsley Analytics Limited | Professional & scientific | 2013 |
| Apsley Precision Engineering Ltd | Manufacturing | 2010 |
| Aptoware Ltd | Information & communication | 2018 |
| APW Contracting Limited | Other services | 2013 |
| AQL Consultants Ltd | Other services | 2021 |
| Aqua (Fenny Stratford) Management Company Limited | Households | 2008 |
| Aqua Design and Leisure Limited | Extraterritorial | 1993 |
| Aqua GAS Salisbury Limited | Construction | 2005 |
| Aqua Hydraulics Limited | Professional & scientific | 1999 |
| Aqua Inspired Ltd | Administrative & support | 2021 |
| Aqua-Dyn Ltd | Water & waste | 2019 |
| Aquafend Limited | Extraterritorial | 2014 |
| Aquaflex Limited | Manufacturing | 1993 |
| Aquatec Plumbing Supplies Limited | Wholesale & retail | 2006 |
| Aquitaine House (Management) Company Limited | Households | 1982 |
| AR Tracks & Blinds Limited | Manufacturing | 2018 |
| Arbaro Consulting Limited | Manufacturing | 2012 |
| Arbatel Antiques Ltd | Professional & scientific | 2011 |
| Arber + Co Limited | Other services | 2026 |
| Arcadia Strategic Consulting Ltd | Professional & scientific | 2026 |
| Arcane Talent Solutions Ltd | Administrative & support | 2025 |
| Arcanis Insight LLP | | 2025 |
| Archetype Property Ltd | Construction | 2020 |
| Archie Forden Coaching Ltd | Health & social care | 2025 |
| Archives & Collections Trading Co. Ltd. | Arts & recreation | 2019 |
| Archway Resilience Limited | Professional & scientific | 2011 |
| Arcstrading Direct Ltd | Wholesale & retail | 2023 |
| Arcx Technology Ltd | Wholesale & retail | 2020 |
| ARD Ware Limited | Information & communication | 2001 |
| Ardent Digital Services Limited | Information & communication | 2019 |
| Ardern Hodges Limited | Manufacturing | 1973 |
| Argentum Networks Limited | Information & communication | 2014 |
| Aria Resort Services (U.K.) Ltd | Administrative & support | 2017 |
| Arilov Limited | Wholesale & retail | 2025 |
| Aris Diagnostic Ltd | Information & communication | 2020 |
| ARK After Dark Ltd | Hospitality | 2026 |
| ARK Wessex Ltd | Wholesale & retail | 2025 |
| Arkson Builders Ltd | Construction | 2023 |
| Arlington House (22 Bourne AV.) Limited | Households | 2002 |
| ARM Environments Group Ltd | Manufacturing | 2018 |
| Armacre Limited | Construction | 2001 |
| Armada South Ltd | Real estate | 2022 |
| Arms Farm Management Company Limited | Households | 2020 |
| Army Parachute Aircraft Company Limited | Administrative & support | 1999 |
| Army Parachute Association | Arts & recreation | 2009 |
| Arosci Ltd | Financial services | 2013 |
| Arosci Trading Limited | Wholesale & retail | 2014 |
| Arquitis Client Support Ltd | Administrative & support | 2019 |
| Arrowline Minibuses Limited | Transport & logistics | 2002 |
| Art of the Imagination Limited | Wholesale & retail | 2006 |
| Artech Air Limited | Energy | 2023 |
| Artemis Technologies Ltd | Manufacturing | 2015 |
| Artificial Flowers Wholesale Ltd | Administrative & support | 2017 |
| Artificial Solutions UK Limited | Information & communication | 2007 |
| Artisan Tiling Ltd | Construction | 2019 |
| Artoro Limited | Information & communication | 2014 |
| Artstore Direct Ltd | Wholesale & retail | 2018 |
| Arun Fields (Horsham) Management Company Limited | Real estate | 2018 |
| Arundel Place Management Limited | Households | 2011 |
| Arundell Yard Limited | Construction | 2024 |
| ARW Engineering Services Limited | Manufacturing | 2018 |
| AS Aesthetic Beauty Pro Ltd | Other services | 2021 |
| Ascb Charitable Fund | Arts & recreation | 2008 |
| Ascb Trading Limited | Administrative & support | 2019 |
| Ascent Agency Limited | Information & communication | 2014 |
| Ascent Business Advisors Limited | Professional & scientific | 2003 |
| Ascot Oaks Estate Management Company Limited | Households | 2025 |
| ASD Transport (Surrey) Ltd | Transport & logistics | 2013 |
| ASG Landscaping Limited | Administrative & support | 2009 |
| ASH Electrical & Plumbing Services Limited | Other services | 2015 |
| Ash-Autos Spares Ltd | Wholesale & retail | 2021 |
| Ashapuri Enterprise Limited | Other services | 2019 |
| Ashbourne Motors Limited | Wholesale & retail | 2002 |
| Ashbridge Court Management Limited | Households | 2003 |
| Ashbridge Gardens Management Company Limited | Real estate | 2020 |
| Ashdown Business Consulting Limited | Professional & scientific | 2015 |
| Ashdown Farm LLP | | 2012 |
| Asheralyna Ltd | Health & social care | 2024 |
| Ashes to Trees Ltd | Wholesale & retail | 2025 |
| Ashfield Trading Estate Management Company Limited | Real estate | 1999 |
| Ashford Group Services Limited | Administrative & support | 2014 |
| Ashlar Historic Building Repair Limited | Construction | 2013 |
| Ashley Brook Limited | Households | 2011 |
| Ashley Crescent Property Limited | Real estate | 2020 |
| Ashley Down Road Management Company Limited | Households | 2008 |
| Ashley Heights Management Company Limited | Households | 2010 |
| Ashmore (Dorset) Management Limited | Households | 1995 |
| Ashton Farms Limited | Agriculture & fishing | 2006 |