| Arkas Midco 2 Limited | London | 2025 |
| Arkas Topco Limited | London | 2025 |
| Arkay Accountancy Services Ltd | London | 2025 |
| Arkay Group Limited | Watford | 2017 |
| Arkay Group London Limited | Watford | 2019 |
| Arkay Holdings Limited | Ashford | 2019 |
| Arke Property Investments Limited | Halifax | 2014 |
| Arkel Limited | Chipping Norton | 2017 |
| Arkell Holdings Ltd | Oswestry | 2022 |
| Arkemis Ltd | Bury St. Edmunds | 2025 |
| Arkenium Group Ltd | London | 2026 |
| Arkenstone Wealth Management Ltd | London | 2014 |
| Arkero Ltd | Newbury | 2025 |
| Arkescope Limited | Hornchurch | 2017 |
| Arketall Limited | Glasgow | 2024 |
| Arkey Ltd | Royston | 2024 |
| Arkfin Limited | Woking | 2012 |
| Arkham Holdings Ltd | Carrickfergus | 2024 |
| Arkhos Limited | Farnham | 2019 |
| Arkios Investments Limited | Belfast | 2024 |
| Arkios Limited | Manchester | 2001 |
| Arkios Wealth Management Limited | Belfast | 2024 |
| Arkitempo Limited | Cranbrook | 2019 |
| Arkjoy Risk Consultants Ltd | Watford | 2022 |
| Arkk Holdings Limited | Letchworth Garden City | 2025 |
| Arkke Capital Ltd | Cardiff | 2020 |
| Arkle Finance Limited | Wellingborough | 1997 |
| Arkle Investments Ltd | Sheffield | 2023 |
| Arkle Trading Group Limited | Stevenage | 2014 |
| Arkleen UK Holdings Limited | London | 2025 |
| Arkley Asset Ltd | Wellingborough | 2023 |
| Arkley Gate Capital Ltd | Harrow | 2023 |
| Arkleywood Limited | East Horsley | 1998 |
| Arklow Capital Limited | London | 2020 |
| Arklow Ltd | Billingham | 2021 |
| Arkm Holdings Limited | Aberdeen | 2022 |
| Arkm Limited | Lutterworth | 2017 |
| Arkmal Ltd | London | 2020 |
| Arkmor Capital Ltd | London | 2025 |
| Arkmp Holdings Limited | Bury St. Edmunds | 2025 |
| Arkn Limited | Wembley | 2007 |
| Arkn Ventures Ltd | London | 2021 |
| Arko Holding Limited | Coventry | 2018 |
| Arkridge Asset Management Ltd | Birmingham | 2026 |
| Arks Jogia Ltd | High Wycombe | 2025 |
| Arks Projects Ltd | Nottingham | 2000 |
| Arksey Holdings Limited | Hailsham | 2013 |
| Arkstone Ever True Group Ltd | Stourbridge | 2026 |
| Arkstone Group Limited | Epsom | 2024 |
| Arkstons Investments Limited | London | 2017 |
| Arktis Ltd | London | 2025 |
| Arkturus Group Ltd | London | 2024 |
| Arkvane Investments Ltd | London | 2026 |
| Arkway Group Ltd | Silsden | 2024 |
| Arkwright Custom Limited | Reading | 2023 |
| Arkwright Insurance Brokers Limited | Bolton | 2005 |
| Arkwright Management Limited | London | 2005 |
| Arkyn Studios Limited | London | 2020 |
| ARL & KO Ltd | London | 2026 |
| ARL Capital Ltd | Cleckheaton | 2026 |
| ARL Financial Planning Ltd | Stockton-On-Tees | 2020 |
| ARL Holdings Limited | Ilkeston | 2026 |
| ARL Newco 2019 Limited | London | 2019 |
| Arla Foods GP Limited | Lockerbie | 2016 |
| Arla Foods Holdings Company Limited | Leeds | 1965 |
| Arladi Holdings Ltd | London | 2026 |
| Arlan Capital Ltd | Northwood | 2023 |
| Arlan Holdings Limited | Bournemouth | 2020 |
| Arlberg Capital Ltd | Redhill | 2013 |
| Arle Capital Partners Limited | Alresford | 2022 |
| Arle Investco Limited | Romsey | 2023 |
| Arle Midco Limited | Romsey | 2023 |
| Arleb Limited | Bedford | 2016 |
| Arlene Jardine Financial Services Limited | Dungannon | 2019 |
| Arlene's Holdings Limited | Edgware | 2020 |
| Arlenia Limited | Newcastle Upon Tyne | 2024 |
| Arlex Limited | Birmingham | 2013 |
| Arley Group Limited | Wilmslow | 2020 |
| Arley Holdings Limited | London | 2020 |
| Arley Ventures Limited | Bolton | 2013 |
| Arlia Broker Services Ltd | St. Neots | 2021 |
| Arlie Hold Co Limited | Manchester | 2024 |
| Arlin Services Holdings Limited | Aberdeen | 2017 |
| Arlingclose Holdings Limited | Stratford-Upon-Avon | 2021 |
| Arlingclose Limited | Stratford Upon Avon | 1993 |
| Arlington AFL Ltd | London | 2024 |
| Arlington Asset Management Limited | London | 2015 |
| Arlington Capital Advisors Limited | London | 2021 |
| Arlington Capital Group Limited | Bradford | 2026 |
| Arlington Capital Ltd | London | 2015 |
| Arlington Consolidated Limited | London | 2025 |
| Arlington Development Management Limited | Wantage | 2024 |
| Arlington Estates Ltd | Wimborne | 2021 |
| Arlington Financial Associates Limited | Barnstaple | 2018 |
| Arlington Focus Property Ltd | London | 2020 |
| Arlington GP Limited | Matlock | 2018 |
| Arlington Group Asset Management Limited | London | 1989 |
| Arlington Insurance Services Limited | Retford | 2005 |
| Arlington Investment Management Limited | Colchester | 2007 |
| Arlington Jones Limited | Kidderminster | 2025 |