| Ardonagh Rocket Investment Holdings Limited | London | 2023 |
| Ardonagh Services Limited | London | 2010 |
| Ardonagh Specialty Holdings 2 Limited | London | 2021 |
| Ardonagh Specialty Holdings Limited | London | 2017 |
| Ardonagh Specialty Limited | London | 2006 |
| Ardonagh Specialty MGA Holdings Limited | London | 2022 |
| Ardonagh Specialty Partridge Limited | London | 2022 |
| Ardor Investments Limited | London | 2015 |
| Ardora Group Limited | Middlesbrough | 2025 |
| Ardorglobalgroup Ltd | London | 2024 |
| Ardour Ventures Ltd. | London | 2005 |
| Ardour World Holdings Limited | Harrow On The Hill | 2022 |
| Ardour-Stoves Limited | Lydney | 2018 |
| Ardronik Ltd | Penrith | 2025 |
| Ards Capital Ltd. | London | 2000 |
| Ards Investment & Trust Company Limited | Bangor | 1960 |
| Ardtanagh Holdings Ltd | Dromore | 2023 |
| Ardtir Holdings Limited | Lisburn | 2020 |
| Ardu Ltd | Belfast | 2015 |
| Ardua Limited | Liverpool | 1998 |
| Ardvarna Holdings Ltd | Belfast | 2021 |
| Ardyn Limited | Sudbury | 2024 |
| ARE Assets W Limited | London | 2020 |
| ARE Capital Advisors Limited | London | 2018 |
| ARE Holdings Ltd | Paignton | 2021 |
| ARE Property Investments Ltd | Barnet | 2014 |
| ARE WE Wayward Limited | Horsham | 2022 |
| Area 51 Holdings Limited | Nottingham | 2023 |
| Area Group Holdings Limited | London | 2023 |
| Area P Limited | Stafford | 2023 |
| AREA51 Group Limited | Neath | 2022 |
| Areas UK F&B Concessions Limited | London | 2026 |
| Areawfi Holding Ltd | London | 2023 |
| Arecor Therapeutics PLC | Saffron Walden | 2021 |
| Aree Holdings Limited | London | 2024 |
| Arefor Holdings Limited | Castle Douglas | 2023 |
| Areg Investment Ltd. | Doncaster | 2018 |
| Areia Capital Ltd | Margate | 2026 |
| Areia Consulting Holding Limited | London | 2023 |
| Areim UK Limited | London | 2022 |
| Arelco Holdings Ltd | London | 2026 |
| Arele Ltd | Looe | 2025 |
| Areli Group Limited | Taunton | 2025 |
| Areli Ltd | Wanstead | 2015 |
| Arelsco Holdings 1 Ltd | London | 2024 |
| Arelsco Holdings 2 Ltd | London | 2024 |
| Arem Group Limited | Manchester | 2018 |
| Aremas Holdings Ltd | Bradford | 2023 |
| Aremco Services Ltd | London | 2020 |
| Aren Capitals Ltd | London | 2024 |
| Aren Holdings Limited | London | 2022 |
| Arena 4 Finance Ltd. | Dorchester | 2004 |
| Arena Club Limited | Kirkcaldy | 2025 |
| Arena Energy Holdings Ltd | Belfast | 2021 |
| Arena Housing Group Pension Trustees Limited | Warrington | 1997 |
| Arena International Equity Markets (UK) Limited | London | 2021 |
| Arena International Strategy Ltd | Hove | 2018 |
| Arena Investment Management Limited | Preston | 1960 |
| Arena Maestro Limited | Hixon | 2024 |
| Arena Personal Credit Limited | Leicester | 2012 |
| Arena Wealth Management Limited | Borehamwood | 1975 |
| Arenal Investments Limited | London | 2019 |
| Arenaplane Limited | Chertsey | 1999 |
| Arenas Molina Group Ltd | London | 2025 |
| Arendair Ltd | Surbiton | 2017 |
| Arenite Specialty Limited | London | 2025 |
| Arenix Cover Ltd | Swanley | 2026 |
| Arenosa Holdings Limited | Droitwich | 2016 |
| Arentis Holdings Limited | Wakefield | 2024 |
| Arentz Capital Ltd | London | 2021 |
| Arenz Family Ltd | Egham | 2021 |
| Arepp Ltd | Dungannon | 2025 |
| Areq Investments Ltd | Aberdeen | 2015 |
| Arer Investments | High Wycombe | 2025 |
| Ares Business Limited | London | 2012 |
| Ares Capital Europe Limited | London | 2007 |
| Ares Capital Group Ltd | London | 2025 |
| Ares Financial Planning Ltd | Nantwich | 2024 |
| Ares Group Holdings Ltd | London | 2025 |
| Ares Initial GP Limited | London | 2015 |
| Ares Initial Limited Partner Limited | London | 2015 |
| Ares International Limited | Leeds | 2018 |
| Ares Management Limited | London | 2006 |
| Ares Management UK (GP) Limited | Edinburgh | 2012 |
| Ares Management UK Limited | London | 2013 |
| Ares MF UK Management Limited | London | 2017 |
| Ares Real Estate Holding Ltd | London | 2020 |
| Ares Security and Training Ltd | Hull | 2025 |
| Ares Systematic Credit Limited | London | 2018 |
| Ares T&C Ltd | Tottenham Hale | 2018 |
| Ares UK CSF Limited | London | 2012 |
| Ares UK Holdco 1 Limited | London | 2026 |
| Ares UK Holdco 2 Limited | London | 2026 |
| Aresh Capital Ltd | Edgware | 2024 |
| Aress Holding Ltd | London | 2025 |
| Arete 69 Holdings Limited | Sheffield | 2024 |
| Arete Bidco Limited | Guildford | 2025 |
| Arete Convexity Trading Ltd | London | 2026 |
| Arete Financial Ltd | London | 2017 |
| Arete Financial Services Ltd | Goffs Oak | 2021 |