| Automatic Engineers Holdings Ltd | Greengates | 2021 |
| Automatic Enrolment Solutions Limited | Rugby | 2015 |
| Automatic Escrow Limited | London | 2020 |
| Automatic Ventures Ltd | London | 2026 |
| Automation & Technology Holdings Limited | Ashton-Under-Lyne | 2024 |
| Automation Consultants Holdings Limited | Reading | 2020 |
| Automation Holdco Limited | Farnborough | 2025 |
| Automation Management Holdings Limited | Chichester | 2025 |
| Automation Workshop Ltd | Walsall | 2024 |
| Automaton Trading Ltd | London | 2022 |
| Automec Holdings Limited | Buckingham | 2017 |
| Automint IO Limited | London | 2026 |
| Automobile Assistance Ltd | Glasgow | 2011 |
| Automobile Association Insurance Services Limited | Basingstoke | 1989 |
| Automobile Association Personal Finance Limited | West Yorkshire | 1983 |
| Automobili Caffè Group Ltd | Mayfair | 2026 |
| Automobili La'Bergitla Endurance Holdings Ltd | London, United Kingdom | 2025 |
| Automoney Trust Limited | Norwich | 2018 |
| Automotivate Holdings Ltd | Sheffield | 2025 |
| Automotivate Leasing Ltd | Sheffield | 2025 |
| Automotive Addiction Investments Ltd | Horley | 2019 |
| Automotive Export Holdings Limited | Preston | 2025 |
| Automotive Finance Associates Ltd | Sunderland | 2017 |
| Automotive Fleet Investments Limited | Huntingdon | 2017 |
| Automotive Innovations (ST. Albans) Holdings Limited | Hemel Hempstead | 2016 |
| Automotive Marketing Services Limited | Bicester | 1998 |
| Automotive Online Ltd | Bournemouth | 2012 |
| Automotive Retention Group Holdings Ltd | Leicester | 2025 |
| Automotive Vision Ltd | Poole | 2011 |
| Autonetic Insurance & Pensions Services (A.I.P.S.) Limited | Nottinghamshire | 1983 |
| Autonomai Holdings Limited | London | 2026 |
| Autonomi Capital Limited | London | 2019 |
| Autonomous Agri Group Limited | Alcester | 2023 |
| Autonomous Business Solutions Limited | Bristol | 2017 |
| Autonomous Capital Ltd | London | 2024 |
| Autonomous Investments Holdings Limited | Bristol | 2020 |
| Autonomy Financial Planning Limited | Craigavon | 2011 |
| Autonomy Holdings Limited | Chester Le Street | 2016 |
| Autonomy Investments Ltd | Liverpool | 2016 |
| Autonomy New Media Limited | Raunds | 2014 |
| Autonomy Service Company Limited | London | 2002 |
| Autonomy Ventures Ltd | London | 2021 |
| Autonomy Wealth Holdings Limited | Wolverhampton | 2024 |
| Autonomy Wealth Limited | Wolverhampton | 2015 |
| Autonomyfp Limited | Banbridge | 2014 |
| Autonoware Limited | Hastings | 2012 |
| Autopack Group Ltd | Hereford | 2025 |
| Autopack Holdings Ltd | Hereford | 2020 |
| Autopack Holdings Spain Ltd | Hereford | 2024 |
| Autoparts Direct Holdings Limited | Belfast | 2022 |
| Autopfect Holdings Limited | Leeds | 2026 |
| Autopoint (Holdings) Limited | Helensburgh | 2013 |
| Autoprotect (MBI) Ltd | Harlow | 2004 |
| Autoprotect Group Limited | Harlow | 2017 |
| Autoquality Wigan Group Limited | Wigan | 2022 |
| Autoquality Wigan Holdings Limited | Wigan | 2015 |
| Autorooms Group Holdings Limited | Nottingham | 2026 |
| Autoscan International (India) Holdings Limited | Coventry | 2016 |
| Autoscope Holdings Limited | Coalville | 2020 |
| Autoshine Worx Ltd | Chester | 2004 |
| Autoslide Ltd | Newbury | 1989 |
| Autosupplies (Holdings) Limited | Birmingham | 2025 |
| Autosupply Holdings UK Limited | Stretford | 2016 |
| Autosure Limited | London | 1984 |
| Autotechnik Holdings Limited | Birmingham | 2019 |
| Autotrans Holding Ltd. | London | 2023 |
| Autovista Bidco Limited | London | 2018 |
| Autovista Financing UK Limited | London | 2018 |
| Autovista Group Limited | London | 2006 |
| Autovista Holdco UK Limited | London | 2006 |
| Autowash Holdings Limited | Hinckley | 2002 |
| Autowave Group Limited | Nottingham | 2021 |
| Autozones 2000 Limited | Smalldole | 1995 |
| Autris Ltd | London | 2025 |
| Autumn Breeze Group Ltd | Potters Bar | 2025 |
| Autumn Fall (Elgin) Ltd | Peterhead | 2019 |
| Autumn Financial Planning Limited | Tunbridge Wells | 2023 |
| Autumn Leaves Holdings Ltd | Wrexham | 2021 |
| Autumn Money Group Ltd | Enfield | 2025 |
| Autumn Money Ltd | Potters Bar | 2025 |
| Autumn Seven Holdings Limited | London | 2020 |
| Autumn Sun Holdings Limited | Guildford | 2016 |
| Autumn Views Limited | Bournemouth | 2002 |
| Autumnal Investments Limited | London | 2026 |
| Autumnhill Two Limited | Newcastle Upon Tyne | 2022 |
| Autus Lifetime Planning Limited | York | 2013 |
| Auurah Capital Ltd | St. Albans | 2025 |
| AUV Holdings Limited | Coventry | 2015 |
| Auwell Holdings Limited | Cheltenham | 2026 |
| AUX Capital Ltd | Warwick | 2025 |
| AUX Group Limited | Derby | 2020 |
| AUX Holdings Ltd | London | 2026 |
| Auxesia Topco Limited | Knutsford | 2021 |
| Auxesis Investments Ltd | London | 2025 |
| Auxey Bidco Limited | London | 2018 |
| Auxey Finco Limited | London | 2018 |
| Auxey Midco Limited | London | 2018 |
| Auxilia Financial Services Ltd | Ilminster | 2022 |
| Auxilium Associates Limited | Kettering | 2018 |
| Auxilium Equity Limited | Birmingham | 2023 |