| Armitage International Limited | Sutton Newport | 1994 |
| Armitt Library and Museum Centre | Ambleside | 1996 |
| Armonico Consort Limited | Warwick | 2003 |
| Armonix Studios Ltd | London | 2025 |
| Armour Rehabilitation and Performance Limited | Spalding | 2026 |
| Armour Training CIC | Harrow | 2025 |
| Armoured Combat Limited | Gloucester | 2021 |
| Armoured Combat Scotland CIC | Edinburgh | 2023 |
| Armourgeddon Limited | Lutterworth | 2006 |
| Armoury Coaching Systems Ltd | Hereford | 2024 |
| Armoury Way London Ltd | Harlow | 2026 |
| Armoury Way Ltd | Harlow | 2025 |
| Armoy Motorcycle Road Racing Club | Ballymoney | 2008 |
| Armstrong Best Ltd | Truro | 2013 |
| Armstrong Dance Ltd | Henley-In-Arden | 2025 |
| Armstrong Events NW Ltd | Liverpool | 2023 |
| Armstrong Fitness Limited | Lutterworth | 2020 |
| Armstrong Music TOO Limited | London | 2016 |
| Armstrong Speech and Drama Ltd | Lancaster | 2021 |
| Armstrong's Guitars Limited | Sunderland | 2020 |
| ARMSTRONG28 Ltd | Liverpool | 2025 |
| Armthorpe Community Library Limited | Doncaster | 2014 |
| Armufa Entertainment Limited | Ashford | 2024 |
| Army Fit Ltd | Ilkley | 2010 |
| Army Flying Museum Limited | Stockbridge | 1987 |
| Army of Emus Ltd | Bristol | 2025 |
| Army Parachute Association | Salisbury | 2009 |
| Army Rugby Union Trust | Aldershot | 2012 |
| Army Winter Sports Association | Aldershot | 2011 |
| Armz Trainz Ltd | Manchester | 2025 |
| Arnali Events Limited | Brentwood | 2023 |
| Arncott Training Facility Limited | Halifax | 2024 |
| Arnewood Imaging Ltd | Bournemouth | 2011 |
| Arnie Keith Limited | Bromsgrove | 2013 |
| Arniss Equestrian Limited | Thatcham | 2011 |
| Arnna Studios Ltd | High Wycombe | 2025 |
| Arnold Circus Stool Ltd | Doncaster | 2026 |
| Arnold Productions Ltd | York | 2026 |
| Arnold Town Football Club Limited | Nottingham | 2005 |
| Arnold's Attic Limited | Hemel Hempstead | 2017 |
| Arnoldpredict Limited | London | 2026 |
| Arnould's Gym & Fitness Limited | Birkenhead | 2020 |
| Arnside Tennis Club Ltd | Salford | 2023 |
| ARO Archive Ltd | Dartford | 2018 |
| ARO Fitness Felixstowe Ltd | Waltham Abbey | 2018 |
| ARO Fitness Ltd | London | 2013 |
| Arockalypse Productions Ltd | Nottingham | 2018 |
| Arora Wellness Studios Ltd | London | 2023 |
| Around the Globe Music & Arts | Islington | 2017 |
| Around the Post Ltd | Twickenham | 2024 |
| Around-A-Bounce Limited | London | 2015 |
| Arowick Limited | Beccles | 2014 |
| Aroya Media Limited | Conyer | 2025 |
| ARP Entertainment Ltd | Ramsgate | 2025 |
| ARP Theatre Limited | Edgware | 2016 |
| ARP4 Limited | Brierley Hill | 2024 |
| Arpana School of Arts Ltd | Coventry | 2025 |
| Arpthetrainingzone Ltd | South Croydon | 2026 |
| ARQ Investments Ltd | Burton-On-Trent | 2025 |
| ARQ Music Ltd | Uttoxeter | 2025 |
| Arrampica Limited | Woking | 2002 |
| Arran COE Music Ltd | Mildenhall | 2019 |
| Arran Gregory Ltd | Amersham | 2014 |
| Arran Sports Association | Brodick | 1995 |
| Arran Topham Ltd | Derby | 2012 |
| Arranazz Sound Equipment Hire Ltd | Blackpool | 2025 |
| Arranfest Limited | Brodick | 2023 |
| Arranged Film Limited | Mold | 2020 |
| Arranpaul Audio Limited | Preston | 2001 |
| Array Theatre Productions Ltd | Y Barri | 2024 |
| ARRC44 Holdings Ltd | Luton | 2026 |
| Arrdee Ltd | Northampton | 2021 |
| Arrentee Sports Management Limited | Ipswich | 2020 |
| Arrgee Music Limited | | 1977 |
| Arrifana Ltd. | Perth | 2014 |
| Arrival Africa Limited | London | 2025 |
| Arrival Entertainment Ltd | Leeds | 2025 |
| Arrival Events Limited | Saltaire | 2024 |
| Arrival Group Ltd | Newton Abbot | 2022 |
| Arrival Productions Limited | Worthing | 2010 |
| Arrk Music Rights Limited | London | 2022 |
| Arrow Creative Limited | Macclesfield | 2025 |
| Arrow Holdings Kent Limited | Wallington | 2020 |
| Arrow Leisure Limited | Twyford | 2000 |
| Arrow Meadow Fisheries Limited | Alvechurch | 2021 |
| Arrow Storage Ltd | Tamworth | 2025 |
| Arrow Strength Ltd | Sunderland | 2023 |
| Arrow Vehicle Franchises Limited | | 1990 |
| Arrowart Limited | Peasedown | 2024 |
| Arrowdox Events Limited | Kington | 2024 |
| Arrows & Traps Theatre Company Ltd | St Albans | 2019 |
| Arrows Darts Venue Ltd | Resolven | 2025 |
| Arrowville Artworks Ltd | Milton Keynes | 2021 |
| Arrthi Ltd | Southampton | 2024 |
| ARS Dramatis Ltd | London | 2025 |
| ARS Marketing Limited | | 1983 |
| Arscott Golf Club Limited | Shrewsbury | 2018 |
| Arsenal Holdings Limited | London | 2001 |
| Arsenal Stadium Management Company Limited | London | 2003 |
| Arsenal Women Football Club Limited | London | 1995 |