| Aquablugames Ltd | Brighton | 2019 |
| Aquacktic Swim School Ltd | Bishop Auckland | 2011 |
| Aquafit Ladies Limited | Kington | 2025 |
| Aquafit Lancashire Limited | Preston | 2025 |
| Aquaforge Limited | Nottingham | 2024 |
| Aquaholics Dive Centre Limited | Portstewart | 2010 |
| Aquaire Limited | Lymington | 2010 |
| Aqualife Swim School Ltd | Arundel | 2014 |
| Aqualife Waterplants & Landscapes Limited | Whitefield | 2005 |
| Aqualights POM and Twirl Troupe Ltd | Poole | 2019 |
| Aquamec Services Limited | Bray On Thames | 2000 |
| Aquanauts Swim School Ltd | Tamworth | 2015 |
| Aquanauts UK Limited | Derbyshire | 2006 |
| Aquanorth Diving Centre Limited | South Shields | 2017 |
| Aquapark Reading Limited | Maidenhead | 2019 |
| Aquarelle Publishing Limited | Rugby | 2005 |
| Aquarium Exploris Limited | Belfast | 2016 |
| Aquarius Archery Club | Stanmore | 2018 |
| Aquarius Design Studio Ltd | Stockton-On-Tees | 2025 |
| Aquarius Golf Club | London | 2009 |
| Aquarius Tour Limited | London | 2018 |
| Aquaschool (Salisbury) Limited | Chandlers Ford | 2004 |
| Aquashan Leisure Ltd | London | 2026 |
| Aquaskills Limited | Croydon | 2015 |
| Aquasplash (Midlands) Limited | Solihull | 2013 |
| Aquasport (Midlands) Limited | Solihull | 2007 |
| Aquasport Limited | Maldon | 2004 |
| Aquastart Limited | Telford | 1985 |
| Aquaswim Ltd | Brighton | 2016 |
| Aquaterra Adventures Limited | Coleraine | 2025 |
| Aquatic Jetpacks Limited | Poole | 2013 |
| Aquatic Learning Limited | Edinburgh | 2003 |
| Aquatzi Ltd | Oldham | 2015 |
| Aquavista Watersides 2 Ltd | Nottinghamshire | 2021 |
| Aquavista Watersides Ltd | Nottinghamshire | 2003 |
| Aquila Leisure Limited | Milton Keynes | 2009 |
| Aquila Community Engagement CIC | Sidcup | 2023 |
| Aquila Sports and Education Ltd | Sidcup | 2019 |
| Aquila T.K.D Limited | Sidcup | 2014 |
| AR Bouncy Castles Limited | Banbridge | 2025 |
| AR Dormant Ltd | Casnewydd | 2025 |
| AR Empire International Ltd | London | 2024 |
| AR England Limited | Cobham | 2017 |
| AR Events Limited | Huddersfield | 2009 |
| AR Fitness Ltd | Feltham | 2013 |
| AR Global Events (UK) Ltd | Corby | 2024 |
| AR Gratia Artis Ltd | London | 2026 |
| AR Holistic Health & Well-Being CIC | Birmingham | 2021 |
| AR Johnston NI Ltd | Fintona | 2021 |
| AR Krav Maga Self-Defence Training Ltd | Wymondham | 2026 |
| AR Multisports 19 Ltd | London | 2019 |
| AR Musicals Ltd | London | 2021 |
| AR Pole Fitness Limited | Crawley | 2021 |
| AR Racing Limited | Eastwood | 2019 |
| AR Sports Ltd | Bradford | 2022 |
| AR Stunts Ltd | Farnborough | 2021 |
| AR Tribute Ltd | Bristol | 2024 |
| AR12 Productions Ltd | Towcester | 2019 |
| AR7 Cricket Coaching Limited | Brierley Hill | 2025 |
| ARA and Flow Limited | London | 2025 |
| ARA Athletic Ltd | Killingworth | 2021 |
| ARA Coaching Ltd | Reading | 2017 |
| ARA Equestrian Limited | Alexandria | 2015 |
| ARA Productions Limited | Battle | 2008 |
| Arabella Dorman Fine Art Commissions Limited | London | 2009 |
| Arabella Sloane Ltd | London | 2026 |
| Arabesq Designs Ltd | London | 2022 |
| Arabesque Artistry Ltd | Pudsey | 2016 |
| Arabesque School of Dance Limited | Coventry | 2009 |
| Arabesque School of Performing Arts Limited | Lancaster | 2024 |
| Arabian Horse Services Limited | London | 2017 |
| Arabian Peninsula Sports and Media Ltd | Ascot | 2015 |
| Arabian Racing Organisation Limited | London | 1999 |
| Arabify Limited | Dewsbury | 2022 |
| Araeen & Bonzanigo Ltd | London | 2015 |
| Aragan Sports Ltd. | Swansea | 2012 |
| ARAGONA23 Limited | London | 2022 |
| Araho Limited | Glasgow | 2020 |
| Aras Cholmcille Trust | Derry | 2003 |
| Arash Fouladvand Corporation Ltd | London | 2024 |
| ARB Access Services Ltd | Carlisle | 2018 |
| ARB Art & Design Ltd | Stevenage | 2023 |
| Arbeau Productions Limited | Langham | 2020 |
| Arbeit Studios Ltd | London | 2017 |
| Arbia Productions Ltd | Southwark | 2019 |
| Arbibet Ltd | London | 2025 |
| Arbo Limited | London | 2021 |
| Arbonauts Ltd | London | 2014 |
| Arbor Vitae Garden Care Ltd | Poole | 2020 |
| Arbour Artists Limited | Stockport | 2019 |
| Arbour Green Productions Limited | | 1994 |
| Arbroath Football Club Limited | Arbroath | 2004 |
| Arbroath Golf Links Limited | Arbroath | 2015 |
| Arbuzz Project Ltd | London | 2012 |
| Arbuzz Talkzz Ltd | London | 2015 |
| ARC 400H Limited | Loughborough | 2023 |
| ARC Broadcasting Limited | Southend-On-Sea | 2019 |
| ARC Centre Limited | Bideford | 2014 |
| ARC Cosmetics Ltd | Leeds | 2018 |
| ARC Drift Experience Ltd | Derby | 2026 |