| Aequitas Topco Limited | Maidenhead | 2024 |
| Aequitate Ventures Limited | Uxbridge | 2021 |
| Aequites Limited | London | 2022 |
| Aequor Investments Limited | London | 2011 |
| Aequus Group Holdings Limited | Bath | 2022 |
| Aequus Investment Holdings Ltd | Maidstone | 2020 |
| Aequus Land Ltd | Birmingham | 2008 |
| Aequus Technical Adjusting Limited | Longfield | 2015 |
| Aequus Wealth Management Ltd | London | 2018 |
| AER Consulting Ltd | Edinburgh | 2025 |
| AER Group Holding Ltd | Box | 2026 |
| AER Group Ltd | Box | 2023 |
| AER Maven Holdings Limited | Saffron Walden | 2025 |
| AER Rents Limited | Harrow | 2014 |
| AER Venture Studios Limited | Box | 2024 |
| Aera Capital UK Ltd | London | 2025 |
| Aerarium Financial Solutions Limited | Lincoln | 2013 |
| Aerco (Holdings) Limited | Broadbridge Heath Horsham | 1996 |
| Aeres Capital Holdings Ltd | Lutterworth | 2020 |
| Aeres Capital Ltd | London | 2018 |
| Aergo Capital Services Limited | Belfast | 1999 |
| Aerial Exposure Group Limited | Richmond | 2025 |
| Aerial Group Limited | Fareham | 2018 |
| Aerial Platforms Group Holdings Limited | Leigh | 2023 |
| Aerioncell Ltd | London | 2025 |
| Aeris Holding Limited | County Durham | 2025 |
| Aerith Group Ltd | London | 2025 |
| Aerium Holdings Limited | Kidlington | 2022 |
| Aerius Associates Limited | London | 2013 |
| Aermach Group Limited | Newport | 2020 |
| Aermech Holdings Limited | Haverfordwest | 2025 |
| Aernovum Aviation Limited | London | 2021 |
| Aero Center Holdings Limited | London | 2026 |
| Aero Engine Group Limited | London | 2026 |
| Aero Engine Services (Holdings) Limited | Pontypridd | 2023 |
| Aero Forgings Bidco Limited | Matlock | 2019 |
| Aero Forgings Midco Limited | Matlock | 2019 |
| Aero Holdings DFW Ltd | London | 2026 |
| Aero Partners Holdings Limited | Southend On Sea | 2025 |
| Aero Services Global Group Limited | Manchester | 2019 |
| Aero Solutions Group UK Limited | Bishop'S Stortford | 2025 |
| Aero Stays Holdings Ltd | Birmingham | 2024 |
| Aeroava Ltd | London | 2021 |
| Aerobynn Reach Ltd | London | 2025 |
| Aerocare Group (Warrington) Limited | Warrington | 2012 |
| Aeroco Group Limited | Stockport | 2021 |
| Aerocomp Limited | Stonehouse | 2004 |
| Aerocool Holdings Ltd | Burscough | 2025 |
| Aerodyne Group Limited | Bourne | 2015 |
| Aeroe Global Corporation Ltd | Beckenham | 2021 |
| Aerofen Graphene Industries Limited | London | 2021 |
| Aeroflex Engineering Group Limited | Bournemouth | 2022 |
| Aerofoil Energy (Holdings) Limited | Macclesfield | 2020 |
| Aerofoil Markets Limited | Colindale | 2017 |
| Aeroforma Technologies Holdings Limited | Cheltenham | 2020 |
| Aerogen Holdings Limited | Alton | 2013 |
| Aerojet Holdings Ltd | London | 2022 |
| Aerolux Holdings Limited | Blackpool | 2025 |
| Aeromatt Solutions Ltd | London | 2016 |
| Aeromedex Holding Ltd | London | 2026 |
| Aeromet Holdings Ltd | Worcester | 2015 |
| Aeron Ventures Limited | Cardiff | 2024 |
| Aerontech Limited | London | 2021 |
| Aeropeople Hold Co Ltd | Wanstead | 2026 |
| Aeros Partners Ltd | High Wycombe | 2012 |
| Aeroservices Holdings Limited | Leeds | 2025 |
| Aerosmith Bidco 1 Limited | Chessington | 2024 |
| Aerosmith Bidco Limited | Chessington | 2024 |
| Aerosmith Midco Limited | Chessington | 2024 |
| Aerospace Asset Capital Ltd | London | 2016 |
| Aerospace Warranty Management Trustee Limited | Dunmow | 2023 |
| Aerotak UK Ltd | Esher | 2024 |
| Aerotex Holdings Limited | West Drayton | 2025 |
| Aerotyne Mortgages Ltd | Hinckley | 2025 |
| Aerovac Systems UK Ltd | London | 2020 |
| Aerovolt SPV Investments Ltd | London | 2025 |
| Aerpart Holdings Limited | London | 2019 |
| Aerton Holdings Limited | Bootle | 2024 |
| AES (YKS) Holdings Limited | Ossett | 2026 |
| AES Ballylumford Holdings Limited | Bristol | 2010 |
| AES Barry Operations Limited | Bristol | 1996 |
| AES Electric Ltd | Bristol | 1988 |
| AES Financial Services Ltd | London | 2007 |
| AES Global Holdings Ltd | Cookstown | 2021 |
| AES Group (Scotland) Ltd | Forres | 2023 |
| AES Group Holdings Limited | Northampton | 2019 |
| AES Holdco Limited | Reading | 2025 |
| AES Holdings Limited | Wokingham | 2025 |
| AES Horizons Investments Limited | Bristol | 1992 |
| AES Overseas Holdings Limited | Bristol | 2008 |
| AES Properties Holdco Limited | Middlesex | 2025 |
| AES TEP Power II Investments Limited | Bristol | 1926 |
| AES Trading Holdco Limited | Middlesex | 2025 |
| AES UK Holdings Ltd | Bristol | 1997 |
| AES Wind Generation Limited | Bristol | 2000 |
| Aes-Marconi Limited | Belfast | 2010 |
| Aesc Apollo Holding Limited | Sunderland | 2023 |
| Aesc Atlantic Holding Limited | Sunderland | 2022 |
| Aesc UK Holding Limited | Sunderland | 2023 |
| Aesculapian Group Limited | London | 2019 |