| ARTEMIS2 Investments Ltd | Grimsby | 2026 |
| Artemisia Global Capital Limited | London | 2023 |
| Artemisia Ltd | Brighton | 2026 |
| Artemisia Ventures Ltd | London | 2024 |
| Artemisx Limited | London | 2026 |
| Artemita Ltd | Mildenhall | 2026 |
| Arten Digital Ltd | Nottingham | 2024 |
| Arteo Holding Ltd | London | 2026 |
| Arteon Holdings Ltd | London | 2026 |
| Arterior Limited | Warrington | 2015 |
| Artery Digital Trust Ltd | Sheffield | 2025 |
| Artes Specialty Limited | Bury St Edmunds | 2021 |
| Artesian Finance III PLC | London | 2005 |
| Artex ILS Services UK Ltd | Kingston Upon Thames | 2017 |
| Artex Risk Solutions (UK) Limited | London | 2012 |
| Artfarm Group Limited | London | 2018 |
| Artfarm Limited | London | 2017 |
| Artform Group Limited | London | 2022 |
| Artform Holdings Limited | London | 2018 |
| Artgro Ltd | Leyland | 2019 |
| Artha AP Holding Ltd | London | 2024 |
| Artha Holding Ltd | London | 2022 |
| Artha IDA Limited | Leicester | 2024 |
| Artha Nirmaan PVT Ltd | London | 2025 |
| Artha Nirvana Ltd | Coulsdon | 2025 |
| Artha Partners Ltd | London | 2017 |
| Artha Trading Ltd | London | 2024 |
| Artha Ventures Limited | Slough | 2021 |
| Artha Vriddhi Investments Ltd | Sevenoaks | 2024 |
| Artha Wealth Management Ltd | Aylesbury | 2021 |
| Artharla Collection Ltd | Norwich | 2026 |
| Arthas Group Limited | Sidcup | 2021 |
| Arthco Holdings Ltd | Bingham | 2025 |
| Arthemis Capital Ltd | London | 2020 |
| Arthingdale Limited | Chester | 2020 |
| Arthington Futures Limited | Otley | 2025 |
| Arthington Ventures Limited | Otley | 2025 |
| Arthog Holdings Ltd | London | 2018 |
| Arthouse Glasgow Holdco Limited | London | 2024 |
| Arthouse Propco Limited | Chandlers Ford | 2026 |
| Arthousemortgages Ltd | London | 2024 |
| Arthur & North Holdings Limited | Farnham | 2021 |
| Arthur & O'Brien Ltd | South Queensferry | 2024 |
| Arthur Beverly Financial Management Limited | Kilsyth | 2008 |
| Arthur Brothers Group Limited | Newport | 2018 |
| Arthur Brown (Insurance Brokers) Limited | Leeds | 1931 |
| Arthur Browns Wealth Management Ltd | Leeds | 2007 |
| Arthur GEE (Holding) Limited | Peterborough | 2018 |
| Arthur George Associates Limited | Redditch | 2013 |
| Arthur George Financial Limited | London | 2023 |
| Arthur Group Holdings Limited | Loughborough | 2025 |
| Arthur Health Ltd | Tunbridge Wells | 2024 |
| Arthur Healthcare Ltd | Tunbridge Wells | 2026 |
| Arthur J. Gallagher (UK) Limited | London | 1974 |
| Arthur J. Gallagher Holdings (UK) Limited | London | 2008 |
| Arthur J. Gallagher Insurance Brokers Limited | Glasgow | 1988 |
| Arthur John Asset Management Ltd | London | 2013 |
| Arthur John Capital Ltd | London | 2013 |
| Arthur Lawrence Wealth Management Ltd | London | 2015 |
| Arthur Markillie Holdings Limited | Wisbech | 2023 |
| Arthur Money Ltd | Kings Langley | 2023 |
| Arthur RAI Holdings Limited | London | 2011 |
| Arthur Rose Limited | Cambridge | 2024 |
| Arthur Samuel Financial Services Limited | Stanmore | 1977 |
| Arthur Stevens Limited | Hertford | 2004 |
| Arthur Stone Holdings Company Ltd | Newport | 2024 |
| Arthur Thomas Holdings Ltd | Plymouth | 2024 |
| Arthur Wheeler Financial Services Ltd | Shanklin | 2023 |
| Arthur Wood & Sons (Holdings) Ltd | Alford | 2017 |
| Arthurs Skips Holdings Limited | Sheffield | 2023 |
| Arti Secure Ltd | Redhill | 2025 |
| Arti Security Solution Ltd | Redhill | 2025 |
| Artia Consultants Limited | London | 1998 |
| Artian Investments Limited | London | 2021 |
| Artic Dreams Investments Limited | London | 2024 |
| Artic Holdings Limited | London | 2018 |
| Articad Holdings Limited | Watford | 2004 |
| Artichoke Holdings Limited | Cheddar | 2016 |
| Artichoke Trustee Ltd | Cheddar | 2026 |
| Articulate Capital Limited | London | 2018 |
| Articulate Sports Ltd | Sheffield | 2024 |
| Articus Business Finance Ltd | London | 2022 |
| Articus Finance Limited | London | 2019 |
| Artiem Group Ltd | Inverness | 2023 |
| Artiem+ Ltd | Inverness | 2023 |
| Artienne Group Limited | St. Helens | 2018 |
| Artifex Group Ltd | Milton Keynes | 2025 |
| Artifex Holding Ltd | London | 2016 |
| Artificial Grass Pitch Investments Limited | London | 2025 |
| Artificial Intelligence Investment Group Limited | London | 2025 |
| Artificial Intelligence Venture Ltd | Leeds | 2021 |
| Artificial Intelligence Wealth Management Limited | London | 2022 |
| Artika Holding Ltd | London | 2025 |
| Artily Group Ltd | Harrogate | 2013 |
| Artilys Group Limited | Stone | 2026 |
| Artimaren Holdings Ltd | Gerrards Cross | 2025 |
| Artimino Holdings Limited | Berkhamsted | 2025 |
| Artin Holding Ltd | Cambridge | 2025 |
| Artina Subsea Ltd | London | 2024 |
| Artinance Capital Ltd | London | 2025 |