| Atwal Holdings Ltd | Hayes | 2025 |
| Atwal Property Group Limited | Wolverhampton | 2018 |
| Atwal's Holdings Ltd | Birmingham | 2026 |
| Atwil Holdings Limited | Brighouse | 2024 |
| Atwood Benefits UK Limited | Retford | 2005 |
| ATWOOD123 Limited | Stanmore | 2014 |
| Atworth Nine Limited | Melksham | 2020 |
| Atya Limited | Brentford | 2022 |
| Atyab AL Marshoud (Holdings) Limited | London | 2020 |
| Atyourtime Group Limited | Harrow | 2020 |
| Atypic AM Holding Ltd | Harrow | 2021 |
| Atypical Investment & Ventures Limited | London | 2011 |
| Atypical Partner Ltd | London | 2018 |
| ATZ Finance Advice Ltd | London | 2026 |
| ATZ Finance Limited | London | 2021 |
| ATZ Investments Holding Ltd | London | 2025 |
| Atzas Hashem Limited | Edgware | 2022 |
| Atzmag Ltd | London | 2022 |
| AU & AU Holdings Ltd | Hayes | 2021 |
| AU 01 Limited | Bolton | 2014 |
| AU and Co Holdings Ltd | Croydon | 2023 |
| AU Bidco Limited | London | 2016 |
| AU Corporate Holdings Limited | Bexhill | 2024 |
| AU Corporate Investments Limited | Bexhill | 2025 |
| AU Courant Solutions Ltd | Guildford | 2017 |
| AU CP Limited | Preston | 2018 |
| AU Defi Ltd | London | 2024 |
| AU Finance Limited | Chester | 2024 |
| AU Global Investments Limited | Coventry | 2024 |
| AU Group Brokers Global Ltd | London | 2026 |
| AU Holdings Group Ltd | Leeds | 2026 |
| AU Holdings Ltd | Stoke-On-Trent | 2025 |
| AU Industrial Limited | Verwood | 2021 |
| AU Investments Limited | Hertfordshire | 2011 |
| AU Lait Ltd | Blandford Forum | 2024 |
| AU Limited | Ashford | 2004 |
| AU Trade Ventures Ltd | Hayes | 2025 |
| AU Wealth Management Ltd | Manchester | 2019 |
| AU51ENZ Ltd | Margate | 2018 |
| AU79 Commodities Limited | Watford | 2008 |
| AU79 Limited | London | 2014 |
| AUA Holding Ltd | London | 2024 |
| AUA Insolvency Risk Services Limited | London | 2007 |
| Auad Holdings Limited | Newtown | 2024 |
| Auag Holdings Ltd | Twickenham | 2021 |
| Aube Capital Ltd | London | 2023 |
| Aube Holding Ltd | Bristol | 2022 |
| Aube Investments Ltd | London | 2023 |
| Aubepine Limited | Leigh-On-Sea | 2026 |
| Auberge PTE (UK) Limited | London | 2012 |
| Auberies Estate (Holdings) Limited | Sudbury | 2013 |
| Aubertin Financial Ltd | Tewkesbury | 2025 |
| Aubin & Wills Holdings Limited | Coventry | 2019 |
| Aubin Holdings Limited | Beckenham | 2022 |
| Auborn Financial Services Limited | London | 1997 |
| Aubrey Capital International Limited | Edinburgh | 2022 |
| Aubrey Capital Management Limited | Edinburgh | 2006 |
| Aubrey Smith Leisure Limited | Glasgow | 1998 |
| Aubreyindia UK Ltd | Glasgow | 2010 |
| Auburn 15 Holdings Limited | London | 2022 |
| Auburn 15 PLC | London | 2022 |
| Auburn Group Holdings Ltd | Hockley | 2023 |
| Aubury Holdings Limited | Crowborough | 2024 |
| Aubussondelpon Ltd | Edinburgh | 2024 |
| Aubyn Investments Ltd | Exeter | 2025 |
| Aucap Limited | London | 2022 |
| Auchenhowie Limited | | 2004 |
| Auchmore Energy Ltd | Muir Of Ord | 2011 |
| Auchmore Power Ltd | Muir Of Ord | 2011 |
| Auchnafree Shareholding Company Limited | Notts | 1962 |
| Auchroisk BDS Limited | London | 2025 |
| Auchroisk Holdings Limited | London | 2016 |
| Auchterarder Investments Limited | Virginia Water | 2023 |
| Auckland Enterprises Ltd | Sheffield | 2023 |
| Auckland Financial Services Limited | Canary Wharf Estate | 2018 |
| Aucta Capital Limited | Strathaven | 2026 |
| Aucteris Limited | Manchester | 2025 |
| Auction Bidco Limited | London | 2020 |
| Auction Holdco Limited | London | 2020 |
| Auction Room Holdings Ltd | Dungannon | 2023 |
| Auction Technology Group PLC | London | 2021 |
| Auctions Holdings Ltd | London | 2025 |
| Auctor Paxos Ltd | Greater London | 2026 |
| Auctus Finance Ltd | Stourport-On-Severn | 2016 |
| Auctus Investments Limited | Huddersfield | 2021 |
| Auctus Real Estate Investments Limited | Bedale | 2026 |
| Auctusx Limited | Ruislip, | 2025 |
| Audacc Consultancy Limited | Cheadle | 2017 |
| Audacc Consultancy South Ltd | London | 2025 |
| Audacious Property Investment Ltd | Erith | 2026 |
| Audacity Capital Ltd | London | 2014 |
| Audacity Global Limited | London | 2018 |
| Audacter Ltd | London | 2019 |
| Audas Group (EOT) Limited | Burnley | 2023 |
| Audax Asset Management Limited | London | 2026 |
| Audax Holdings (UK) Limited | Galashiels | 2024 |
| Audax Management Company (UK) Limited | Bristol | 2022 |
| Audaxis Consulting Limited | Eythorne | 2014 |
| Audbern Limited | Hertford | 2009 |
| Audemars Corporate Risk Solutions Ltd | Birmingham | 2013 |