| Arnoldact Rose Limited | Brighton | 2003 |
| Arnolds Group Holdings Limited | Fareham | 2020 |
| Arnos Holdings Limited | London | 2006 |
| Arnot Tower Holdings Limited | Glenrothes | 2025 |
| Arnott GUY & Co Ltd | Eastbourne | 2004 |
| Arnould Hill Limited | London | 2017 |
| Arnskee & Co Limited | Fareham | 2024 |
| Arnw Developments Limited | Rye | 2022 |
| Arny Finance Limited | London | 2019 |
| Arny Investments Limited | London | 2025 |
| Arnz Trading Limited | London | 2016 |
| ARO Fitness Holdings Ltd | Waltham Abbey | 2018 |
| ARO Holdings Limited | Bishop'S Stortford | 2020 |
| ARO UK Investment Ltd | London | 2025 |
| ARO Underwriting Group Limited | Westerham | 2011 |
| Arob Services Limited | London | 2012 |
| Aroco Impact Capital Ltd | London | 2025 |
| Arodon UK Limited | London | 2015 |
| Aroha Ventures Ltd | London | 2026 |
| Arohana Capital Limited | London | 2025 |
| Arol Consulting Ltd | Swindon | 2011 |
| Aroma Global Gateway Ltd | Newcastle Upon Tyne | 2021 |
| Aroma Holdings Cheltenham Ltd | Cheltenham | 2024 |
| Aromaeya Holdings Ltd | London | 2026 |
| Aromatherapy Associates Holdco Limited | London | 2022 |
| Aromatherapy Investments Holding Limited | London | 2014 |
| Aromatherapy Investments Limited | London | 2014 |
| Aroni Limited | Market Harborough | 2020 |
| Arontone Limited | Isleworth | 1978 |
| Arora (Bedfont Court) Limited | Hounslow | 2026 |
| Arora (Gatwick) North Holdings Limited | Hounslow | 2026 |
| Arora Alliance Ltd | Wembley | 2025 |
| Arora Family Ltd | London | 2019 |
| Arora Hammersmith Hotel Limited | London Heathrow Airport | 2024 |
| Arora Hammersmith Limited | Hounslow | 2025 |
| Arora Hammersmith Metro Limited | Hounslow | 2025 |
| Arora Heathrow Limited | Hounslow | 2025 |
| Arora Holdco Limited | London | 2025 |
| Arora Hotels Limited | Hounslow | 2005 |
| Arora Investments Jput Limited | Hounslow | 2006 |
| Arora Metro Investor Limited | Hounslow | 2025 |
| Arora Property Investments Holdings Limited | Hounslow | 2026 |
| Arora ST James Limited | London | 2025 |
| Arora Tower Limited | Hounslow | 2025 |
| Arora UK Finance Limited | Hounslow | 2021 |
| Arora Waterfront Holdings Limited | Hounslow | 2020 |
| Aros Kapital Limited | London | 2020 |
| Arosa Foundation C.I.C. | London | 2024 |
| Arosci Ltd | Salisbury | 2013 |
| Arose Finance Limited | Billericay | 2021 |
| Arosh Finance Ltd | Westcliff-On-Sea | 2018 |
| Arosh Limited | Westcliff-On-Sea | 2017 |
| Arossurance Ltd | Bexleyheath | 2024 |
| Aroul's Limited | Oxford | 2010 |
| Around the Houses Limited | Wadebridge | 2021 |
| Arowanis Holdings Limited | Hull | 2017 |
| Aroza Estates Limited | Manchester | 2025 |
| ARP Design Holdings Limited | Gateshead | 2016 |
| ARP Financial Planning Limited | Glasgow | 2025 |
| ARP Glasgow Limited | Larkhall | 2018 |
| ARP Latam Holdco Ltd | Warmley | 2019 |
| ARP North America Holdco Ltd | Warmley | 2019 |
| ARP Property Holdings Limited | Doncaster | 2023 |
| ARP Property Services Limited | Ashington | 2018 |
| ARP42 Ltd | Exeter | 2016 |
| Arpac Trading Ltd | London | 2003 |
| Arpan Property Limited | Edinburgh | 2026 |
| Arpee Consulting Limited | Aylesford | 2025 |
| Arpenteur Eltham Holdings Limited | Tunbridge Wells | 2022 |
| Arpg Investments Ltd | Liverpool | 2018 |
| Arphaxad Limited | Hereford | 2020 |
| Arpista Limited | Cheltenham | 2021 |
| Arpora Holding Limited | Bedford | 2026 |
| ARQ Financial Planning Ltd | Cannock | 2026 |
| Arqen Holdings Ltd | Corby | 2025 |
| Arqera Capital Limited | Leeds | 2026 |
| Arqiva Intermediate Limited | Winchester | 2021 |
| Arqiva Pension Trust Limited | Winchester | 1997 |
| Arquant Management Limited | London | 2020 |
| Arqueopolis Ltd | London | 2013 |
| Arquero Wolfe Limited | Stratford Upon Avon | 2025 |
| Arquet Limited | Ledbury | 2011 |
| Arquitis Financial Management Limited | Cirencester | 2016 |
| ARR Advisory Limited | Solihull | 2026 |
| ARR Investment Partners Ltd | London | 2018 |
| Arrakeen Group Ltd | Edinburgh | 2026 |
| Arrakis Commercial Enterprise Ltd | Brockenhurst | 2013 |
| Arrakis Investments Limited | London | 2017 |
| Arrakis Properties Limited | Bury St Edmunds | 2023 |
| Arrakis Trading Limited | London | 2017 |
| Arran Finance Limited | Wrexham | 1997 |
| Arrandahl Trading Company Ltd | Basingstoke | 2026 |
| Arrange Holdings Ltd | Stroud | 2026 |
| Arranglen Limited | Greenock | 1998 |
| Array Investments Limited | Birchwood | 2016 |
| Arrayhan Property Ltd | Cardiff | 2025 |
| Arrc Holdings Limited | Dyce | 2007 |
| Arrdee Holdings Ltd | Northampton | 2021 |
| Arrec Investment Limited | Rugby | 2020 |
| Arrefco Ltd | Stroud | 2020 |