| Archytas Strategic Planning Limited | Cardiff | 2012 |
| Arcivo Holding Company Ltd | London | 2021 |
| Arcix Ltd | Wolverhampton | 2025 |
| Arck Holdings Ltd | Dundee | 2026 |
| Arclink Fiber (US) Limited | London | 2026 |
| Arcmont Asset Management Limited | London | 2019 |
| Arco Commercial Finance Ltd | Cuffley | 2012 |
| Arco Consortium Limited | London | 2020 |
| Arco Financial Ltd | Broadstairs | 2021 |
| Arco Investors Ltd | Crowthorne | 2025 |
| Arco Noble Ltd | London | 2026 |
| Arcode Europe Limited | London | 2006 |
| Arcoh Holdings Limited | Belfast | 2021 |
| Arcon Holdings Limited | London | 2018 |
| Arconi Invest Limited | London | 2023 |
| Arconia Holdings Limited | Team Valley Trading Estate | 2011 |
| Arconte Limited | London | 2023 |
| Arcot Commercial Ltd | Whitley Bay | 2018 |
| Arcovian (Holdings) Ltd | Alcester | 2026 |
| Arcpoint Group Ltd | Milnthorpe | 2026 |
| Arcpoint Ltd | London | 2019 |
| Arcr Holding Ltd | Brighton | 2026 |
| Arcs Group Limited | Bridgend | 2021 |
| ARCS(PH)2 Limited | Maidstone | 2023 |
| Arcsten Capital Limited | London | 2025 |
| Arcstone Holdings Limited | London | 2019 |
| Arcstone Hospitality Limited | London | 2019 |
| Arcstone Living Limited | London | 2019 |
| Arcstone Loan Notes Portfolio 1 Limited | London | 2019 |
| Arcstone Partners Ltd | London | 2025 |
| Arcstone Portfolio 2 Limited | London | 2020 |
| Arcstone Portfolio 3 Limited | London | 2020 |
| Arcsus Holding Limited | Heanor | 2017 |
| Arcsus IT Solutions Holdings Limited | Heanor | 2022 |
| Arcsus Property Holding Ltd | Heanor | 2026 |
| Arcsys Syndicate Ltd | Carshalton | 2025 |
| Arctan Capital Limited | London | 2011 |
| Arctec Group Limited | Crewe | 2021 |
| Arctic Forest Ltd | Pencoed, Bridgend | 2003 |
| Arctic 1 Developments Limited | Sutton Coldfield | 2020 |
| Arctic Captial Limited | London | 2025 |
| Arctic Credit Partners Limited | London | 2025 |
| Arctic Estates Dalston Limited | London | 2013 |
| Arctic Group Holdings Limited | Weybridge | 2025 |
| Arctic Innovations Limited | London | 2014 |
| Arctic Motion Limited | Wrexham | 2018 |
| Arctic Pandi Ltd | London | 2025 |
| Arctic UK Bidco Limited | London | 2025 |
| Arctic Ventures Ltd | London | 2022 |
| Arcticstar Limited | London | 1999 |
| Arctis Management UK Limited | London | 2019 |
| Arctos Group Holdings Ltd | Leeds | 2026 |
| Arctos Holdings Limited | London | 2015 |
| Arctos UK Capital Limited | London | 2023 |
| Arctos UK IM Limited | London | 2023 |
| Arcturus Capital Advisors Ltd. | Rye | 2015 |
| Arcturus Capital Limited | Glasgow | 2021 |
| Arcturus Restaurant Group Limited | London | 2024 |
| Arcturus Ventures Ltd | Putney | 2018 |
| Arculus Holdings Ltd | London | 2024 |
| Arcura (Holdings) Limited | Croydon | 2017 |
| Arcus 101 Limited | Altrincham | 2023 |
| Arcus Capital (Management) Ltd | Norwich | 2025 |
| Arcus Capital (Oakwood) Ltd | Norwich | 2019 |
| Arcus Capital Ltd | Norwich | 2013 |
| Arcus Group Holdings Ltd | London | 2026 |
| Arcus Group Services Limited | Llandrindod Wells | 2023 |
| Arcus Holdings Ltd | Llandrindod Wells | 2021 |
| Arcus Investment Holdings Limited | Worthing | 2020 |
| Arcus Investment Limited | Worthing | 1998 |
| Arcus Partners (AR) Limited | Guildford | 2022 |
| Arcus Partners (IM) Limited | Guildford | 2022 |
| Arcus Partners (MS) Limited | Guildford | 2022 |
| Arcus Partners Group Limited | Guildford | 2022 |
| Arcusin Principle Hydrodynamics & Energy Co. Limited | Warwick | 2020 |
| Arcuvi Limited | London | 2026 |
| Arcweld (Holdings) Ltd | Glasgow | 2024 |
| ARD Bhearna Limited | Enniskillen | 2023 |
| ARD Cluain Ltd | Londonderry | 2024 |
| ARD Contracts Holding Limited | Limavady | 2023 |
| ARD Properties (Holdings) Limited | Peterhead | 2021 |
| Arda Capital Limited | Westminster | 2009 |
| Ardagh HP Holding Ltd | Deeside | 2021 |
| Ardagh Metal Packaging Holdings Limited | Deeside | 2021 |
| Ardagh Metal Packaging Pension Trustee Limited | Deeside | 2022 |
| Ardagh Packaging UK Holdings Limited | London | 2021 |
| Ardan Limited | London | 2022 |
| Ardan Ventures Ltd | Belfast | 2026 |
| Ardaros Capital Investments Limited | Dartmouth | 2018 |
| Ardate Limited | York | 2025 |
| Ardbennie Zimbabwe Properties Limited | High Peak | 2001 |
| Ardc (UK) Limited | Colchester | 2013 |
| Ardcast Limited | Huntly | 2023 |
| Ardcastle Developments Ltd | Weybridge | 2025 |
| Arddun Holdings Limited | London | 2025 |
| Ardea Investment Management (UK) Limited | London | 2020 |
| Ardee Consulting Ltd | London | 2025 |
| Ardee Holdings Limited | Leeds | 2026 |
| Ardeen Group Limited | Newcastle | 2021 |
| Ardema Ltd | London | 2023 |