| Autologyx Group Ltd | London | 2017 |
| Autologyx Worldwide Ltd | London | 2017 |
| Autolux Supplies Ltd | Leigh | 2023 |
| Automate Global Ltd | Solihull | 2023 |
| Automatic Door Care Limited | Derbyshire | 1967 |
| Automatic Entry Solutions Limited | Doncaster | 2013 |
| Automatic Mist & Sprinkler Company Ltd | Rye | 2013 |
| Automatic Retailing (Vending) Limited | Cramlington | 2017 |
| Automatic Retailing Coffee Services Limited | Cramlington | 2011 |
| Automatic Systems Laboratories Limited | Sevenoaks | 2012 |
| Automations for Coaches Limited | Cambridge | 1993 |
| Automatrix Ventures Ltd | London | 2025 |
| Automax Industry Co., Ltd | Beckenham | 2006 |
| Automobile Armour Ltd | Norwich | 2024 |
| Automobile Association Holdings Limited | Basingstoke | 1996 |
| Automobile Association Insurance Services Holdings Limited | Basingstoke | 1989 |
| Automobile Association Services Limited | Basingstoke | 1905 |
| Automobile Electrics Limited | | 1931 |
| Automold Ltd. | Beckenham | 2024 |
| Automotive (South Wales) Ltd | Pontyclun | 2011 |
| Automotive Accountants Ltd | Coventry | 2024 |
| Automotive and Tractor Spares England Limited | Pinner | 2003 |
| Automotive Brokers INT Ltd | London | 2015 |
| Automotive Risk Management Limited | York | 2008 |
| Automotive Support Services Limited | Camberley | 2026 |
| Automoto Car Care Ltd | London | 2019 |
| Automotrade Ltd | Leeds | 2023 |
| Autonexa Dynamics Ltd | London | 2025 |
| Autonomo UK Limited | Edinburgh | 2023 |
| Autonomous FS Ltd | Clarkston | 2019 |
| Autonomous Marine Limited | Newport | 2024 |
| Autonomous Software Ltd | Sheffield | 2026 |
| Autonomow Ltd | Haverhill | 2022 |
| Autonomy Cubed Ltd | London | 2024 |
| Autonomy Music Publishing Ltd | London | 2017 |
| Autonomy Squared Ltd | London | 2024 |
| Autonumbers Ltd | London | 1999 |
| Autoparts Network Trading Ltd | Huddersfield | 1997 |
| Autopeople Limited | Retford | 2008 |
| Autopilot Driving School Limited | London | 2021 |
| Autopinnacle Ventures Ltd | London | 2025 |
| Autopoiesis Limited | London | 2022 |
| Autopulse Innovators Ltd | London | 2025 |
| Autoquasar Innovations Ltd | London | 2025 |
| Autoquotient Dynamics Ltd | London | 2025 |
| Autorim Limited | High Peak | 2026 |
| Autorise Industrial Ltd | London | 2015 |
| Autos on Show Limited | Hook | 2017 |
| Autosafety Centres (U.K.) Limited | Gravesend | 1980 |
| Autosales Limited | London | 1999 |
| Autoscales Limited | Blackburn | 2007 |
| Autoservice Patricia Ltd | Hounslow | 2016 |
| Autosmart Group Limited | Lichfield | 2003 |
| Autosome Ltd | Vale Road Heaton Mersey | 2001 |
| Autosonal Industry Co., Ltd | Cambridge | 2019 |
| Autosphere Innovations Ltd | London | 2025 |
| Autosport Solutions Limited | Bordon | 2018 |
| Autostrive Dynamics Ltd | London | 2025 |
| Autotag Limited | Bristol | 2012 |
| Autotech Dynamics Ltd | London | 2020 |
| Autotech Reserve Ltd | London | 2023 |
| Autotek Systems Limited | Bristol | 2015 |
| Autotint Limited | Henley-On-Thames | 1994 |
| Autotrack (Birmingham) Limited | Stroud | 2004 |
| Autotronic Ltd | Hayes | 2023 |
| Autovan Limited | Wimborne | 2006 |
| Autowash Detailing Specialists Limited | Hornchurch | 2010 |
| Autowash Engineering Services Limited | Hinckley | 2002 |
| Autoweigh Scales Ltd | Hereford | 2026 |
| Autowoodcraft Nextstep Invest Limited | London | 2023 |
| Autrad Distribution Co. Limited | Newtownards | 1978 |
| Autrise Group Limited | Beckenham | 2018 |
| Auttreats Ltd | Sheffield | 2012 |
| Autum Management Limited | Leicester | 2017 |
| Autumn & Alder Ltd | London | 2025 |
| Autumn and MAY Toiletries Limited | Leeds | 2001 |
| Autumn Foods Limited | Norwich | 1998 |
| Autumn Glow Ltd | London | 2025 |
| Autumn Grove Management Limited | Bromley | 2005 |
| Autumn Homes Limited | Ringwood | 2024 |
| Autumn Housing Ltd | London | 2024 |
| Autumn Leaflet Distribution Limited | Solihull | 2018 |
| Autumn Music Ltd | Otterton | 2012 |
| Auwa Limited | London | 2026 |
| Auxilium Administration UK Limited | Bath | 2020 |
| Auxilium Directors UK Limited | Bath | 2020 |
| AV and Data Ltd | London | 2013 |
| AV Birch Developments Limited | Bridgnorth | 1992 |
| AV Employees Trustees Limited | Belfast | 2023 |
| AV Support Limited | Southampton | 2024 |
| Av-Sax Limited | Huddersfield | 2015 |
| AV45EATS Limited | London | 2021 |
| AV8SMS Limited | Hull | 2015 |
| AVA Bridge Limited | Hythe | 2022 |
| AVA Lifts Limited | Hythe | 2022 |
| AVA MAE Media Ltd | Rossendale | 2024 |
| Avahana Marine Ltd | London | 2026 |
| Avaho Limited | Farnham | 2014 |
| Available 247 Ltd | Camberley | 2022 |
| Available Vehicles Limited | Derby | 2000 |