| Argo Engineering Trustee Company Limited | Southampton | 2025 |
| Argo Fxco Limited | London | 2022 |
| Argo Holdings Limited | Birmingham | 2025 |
| Argo Innovation Ltd | Stanmore | 2023 |
| Argo International Holdings Limited | London | 2008 |
| Argocat Limited | Llanidloes | 2002 |
| Argoco Holdings Limited | Lympsham | 2017 |
| Argoed Wealth Management Ltd | Blackwood | 2016 |
| Argohurst Holdings Limited | Peterborough | 2020 |
| Argon Capital Investments Limited | London | 2020 |
| Argon Financial Services Limited | Twickenham | 2018 |
| Argon Holdings Ltd | London | 2022 |
| Argon Peak Holdings Limited | Lancing | 2023 |
| Argonath Limited | Hastings | 2020 |
| Argonaut Paraplanning Consultants Ltd | Reigate | 2013 |
| Argonaut Private Capital Limited | London | 2026 |
| Argonautae Limited | London | 2015 |
| Argont Limited | Glasgow | 2026 |
| Argos Business Solutions Limited | London | 1996 |
| Argospay Ltd | London | 2025 |
| Argosy Developments (Primrose Road) Limited | London | 2022 |
| Argosy Developments (UK) Limited | London | 2022 |
| Argosy Residential Holdings (UK) Limited | London | 2023 |
| Args Group Holdings Limited | Dartford | 2020 |
| Argun Resources Limited | London | 2024 |
| Argus Bidco Limited | Wokingham | 2018 |
| Argus GH Limited | Hartlepool | 2023 |
| Argus Group Holdings Ltd | Glasgow | 2020 |
| Argus Midco Limited | Wokingham | 2018 |
| Argus Security Holdings Ltd | Stretford | 2023 |
| Argus Topco Limited | Wokingham | 2018 |
| Argus Ventures Holdings Limited | Lincoln | 2025 |
| Argy Capital Investments Ltd | London | 2025 |
| Argyle 1377 Ltd | Glasgow | 2025 |
| Argyle 145 Ltd | London | 2022 |
| Argyle Acquisitions Ltd | Nottingham | 2026 |
| Argyle Care Limited | Bushey | 2021 |
| Argyle Commercial Finance Limited | Edinburgh | 2024 |
| Argyle Consultants Limited | | 2006 |
| Argyle Consulting Group Limited | | 2006 |
| Argyle Consulting Limited | | 1997 |
| Argyle Financial Group Limited | | 2006 |
| Argyle Financial Services & Planning Limited | Glasgow | 2015 |
| Argyle Financial Services Limited | | 2007 |
| Argyle Investments Ltd. | Glasgow | 2011 |
| Argyle Planning Limited | Glasgow | 2014 |
| Argyle Private Office Ltd | Glasgow | 2013 |
| Argyle Wealth Management Ltd. | Glasgow | 2011 |
| Argyll & Bute Consultants Ltd | Tarbert | 2011 |
| Argyll Covenant Advisory Limited | London | 2013 |
| Argyll Development Holdings Limited | Dunoon | 2026 |
| Argyll Drummond Financial Services Ltd | Goole | 2021 |
| Argyll Financial Planning Ltd | London | 2024 |
| Argyll Financial Services Limited | Dunoon | 2012 |
| Argyll Group Holding Ltd | London | 2026 |
| Argyll Independent Ltd | Loanhead | 2022 |
| Argyll Infrastructure Holdings Limited | Dunoon | 2025 |
| Argyll Stirling Wealth Management Ltd | York | 2019 |
| Argyll Trustees Limited | Fortrose | 2010 |
| Argyll Wealth Consultants Limited | Tarbert | 2003 |
| Argyrus Financial Consultants Limited | London | 2017 |
| ARH Financial Ltd | Verwood | 2023 |
| ARH Holdco Limited | Stoke-On-Trent | 2019 |
| ARH International Financial Consulting Ltd | Weybridge | 2018 |
| Arha Holdings Ltd | Birmingham | 2025 |
| Arham Management Ltd | Cheadle | 2020 |
| Arhase Advisory Limited | Cheadle | 2025 |
| Arhat Capital Ltd | 139 Fountainbridge | 2017 |
| Arhea Ventures Ltd | London | 2025 |
| Arhivi Limited | Northampton | 2014 |
| Arhj Holdings Limited | Norwich | 2019 |
| Arho-Hpd Properties Limited | Sheffield | 2018 |
| Arhouse Group Ltd | Birmingham | 2025 |
| Arhs 1 Limited | London | 2019 |
| Arhs 2 Limited | London | 2019 |
| ARI Consultancy Limited | Witney | 2001 |
| ARI Holdings Limited | Watford | 2015 |
| ARI Pers UK Holdings Ltd | Aberystwyth | 2026 |
| Aria & CIE Ltd | London | 2022 |
| Aria Bidco Limited | Nottingham | 2023 |
| Aria Capital Holdings Ltd | Wolverhampton | 2025 |
| Aria Development Holdings Limited | London | 2025 |
| Aria Emsley Ltd | Immingham | 2024 |
| Aria Finance Limited | Watford | 2002 |
| Aria Financial Limited | Swindon | 2019 |
| Aria Franks Ltd | Rotherham | 2022 |
| Aria Global Management Ltd | London | 2018 |
| Aria Global Services Ltd | Uxbridge | 2016 |
| Aria Grace Group Limited | London | 2025 |
| Aria Group Limited | Purley | 2015 |
| Aria Holdco Limited | London | 2026 |
| Aria Investments Ltd | London | 2013 |
| Aria Peri Capital Limited | Lancing | 2024 |
| Aria Private Clients Limited | Guildford | 2009 |
| Aria Remit Limited | London | 2014 |
| Aria Tech Investments Limited | Wilmslow | 2023 |
| Ariadne Holdings Limited | London | 1970 |
| Ariadne Software Holdings Limited | Cheshire | 2020 |
| Arial (London) Ltd | Elstree | 2024 |
| Arial Ltd | Elstree | 2022 |