| Ariane Systems UK Limited | Wallingford | 2005 |
| Arianna Fine Jewels Ltd | London | 2026 |
| Ariarm Ltd | London | 2023 |
| Ariaverve Group Ltd | London | 2025 |
| Aribel Maintenance Engineering Ltd | South Ockendon | 2025 |
| Arichy Limited | Belfast | 2024 |
| Aricode Printing Technology Ltd. | Cambridge | 2017 |
| Aridom Sanex Ltd | Weavering | 2021 |
| Ariel Bikes Ltd | Bury St. Edmunds | 2020 |
| Ariel Component Parts Limited | Nottingham | 2020 |
| Ariel Couture Limited | London | 2025 |
| Ariel Electric Limited | Crewkerne | 1991 |
| Ariel Ltd | Crewkerne | 2008 |
| Ariel Manufacturing Limited | Crewkerne | 1999 |
| Ariel Motor Company Limited | Crewkerne | 2008 |
| Ariel Motorcycles Limited | Crewkerne | 2013 |
| Ariel Packaging Ltd | Horley | 2011 |
| Ariel Patisserie Limited | Colchester | 2025 |
| Ariel Plastics Limited | Chesterfield | 1988 |
| Ariela Limited | London | 2024 |
| Arielle (U.K.) Company Limited | West Midlands, England, | 2024 |
| Arien Designs Limited | Bristol | 2013 |
| Arien Signs Limited | Highbridge | 2024 |
| Ariens Technical Services Limited | St Nicholas At Wade | 2022 |
| Aries & Taurus Ltd | Swindon | 2025 |
| Aries Arise Ltd | London | 2014 |
| Aries Duct FIX Ltd | Axminster | 2014 |
| Aries Dust Extraction Ltd | Axminster | 2012 |
| Aries Embroidery Limited | Portsmouth | 2001 |
| Aries Energy Solutions Ltd | Brentford | 2024 |
| Aries Machine Services Ltd | Axminster | 2017 |
| Aries Marine Limited | Wallsend Upon Tyne | 2002 |
| Aries Motorworks Ltd | London | 2021 |
| Aries Packaging Limited | Canvey Island | 2024 |
| Aries RAM Cosmeceuticals Limited | Twickenham | 2022 |
| Aries Salon Limited | London | 2026 |
| Arietta Musical Concepts Limited | Bracknell | 2020 |
| Arigen Biotechnology Ltd | Ashford | 2006 |
| Ariike Deborah Ltd | London | 2025 |
| Arikboga Electrical Ltd | London | 2021 |
| Arike Limited | Mildenhall | 2020 |
| Arike Organics Ltd | Glasgow | 2022 |
| Aril Jewels Ltd | Northamptonshire | 2021 |
| Arim Consultancy Limited | Milton Keynes | 2020 |
| Arim Welding Ltd | Peterborough | 2016 |
| Arimo Motor Ltd | Harrow | 2009 |
| Arin Co Bedmakers Ltd | Dewsbury | 2017 |
| Arinaz Company Ltd | London | 2024 |
| Arinsdale Limited | Grangemouth | 1986 |
| Ario Worldwide Limited | Bromley | 2026 |
| Ario's World Ltd | London | 2025 |
| Arion Aviation Limited | Westgate-On-Sea | 2013 |
| Arion Embroidery and Print Ltd | Sleaford | 2021 |
| Arion Engineering Ltd | Birkenhead | 2007 |
| Arion Financial Limited | Wallington | 2007 |
| Arion Fire Solutions Ltd | Sidcup | 2018 |
| Ariphone Records and Industries Ltd. | London | 2025 |
| Aris Jewellers Limited | Bournemouth | 2011 |
| Arise Digital Media Limited | Wigan | 2016 |
| Arise Lifts Ltd | Andover | 2021 |
| Arise Trading Ltd | London | 2018 |
| Ariseclo Ltd | Coatbridge | 2025 |
| Arisha Services Limited | West Drayton | 2017 |
| Arista Electronic Systems Ltd | High Wycombe | 2018 |
| Aristaeus Elements Ltd | London | 2019 |
| Aristan Laboratories International Ltd | Macclesfield | 2024 |
| Aristides Philippides Ltd | Blackburn | 2024 |
| Aristo Fabrics Limited | | 1986 |
| Aristo Haus Ltd | Heckmondwike | 2024 |
| Aristocrat FLY Fishing & Heritage FLY Tying CIC | Winchester | 2026 |
| Aristocrats House of Fashion and Couture Ltd | Dundee | 2019 |
| Ariston Acoustics Limited | London | 1993 |
| Ariston Audio Limited | London | 1993 |
| Ariston Consultancy Ltd | Liverpool | 2026 |
| Aristopets Limited | London | 2025 |
| Aristos Bedroom & Kitchen Limited | Hounslow | 2022 |
| Ariur Studio Limited | Basildon | 2025 |
| Ariyan Trading Ltd | Cardiff | 2025 |
| Ariz Property Services Ltd | Ilford | 2025 |
| ARJ CRE8 Limited | Plymouth | 2014 |
| ARJ Electric Ltd | Watford | 2024 |
| ARJ Enterprises Ltd | London | 2025 |
| ARJ Industries Limited | Birchington | 2010 |
| ARJ Print UK Ltd | Milton Keynes | 2026 |
| ARJ Welding & Fabrication Ltd | Stowmarket | 2026 |
| Arjo UK Limited | Dunstable | 2017 |
| Arjo Wiggins Fine Papers Limited | London | 1969 |
| Arjobex Limited | Brentwood | 1964 |
| Arjobex Polyart Limited | Clacton-On-Sea | 2019 |
| Arjowiggins Scotland Limited | Glasgow | 2019 |
| ARK (NE) Ltd | Gateshead | 2024 |
| ARK (UK) Limited | London | 2013 |
| ARK Airconditioning Limited | Leicester | 1990 |
| ARK Alliance Limited | Glasgow | 2018 |
| ARK and Cross Limited | London | 2024 |
| ARK Beds Ltd | Chatham | 2026 |
| ARK Bespoke Joinery Lincs Ltd | Gainsborough | 2017 |
| ARK Birch Customs Limited | Walton-On-Thames | 2020 |
| ARK Branded Products Ltd | Lisburn | 2019 |
| ARK Caravans and Trailers Ltd | Wokingham | 2021 |