| Arthemy Ltd | London | 2026 |
| Arthenica Ltd | London | 2022 |
| Arthera Fintech Limited | London | 2025 |
| Arthertz | London | 2009 |
| Arthlink Systems Limited | Reading | 2024 |
| Arthos IO Limited | London | 2023 |
| Arthos U.K. Ltd | London | 2025 |
| Arthouse Crouch END Ltd | Rainham | 2026 |
| Arthouse Films Limited | Henfield | 2014 |
| Arthouse Studio Ltd | London | 2023 |
| Arthouse Theatrical Releasing Limited | London | 2010 |
| Arthritis Care | London | 1954 |
| Arthrofilm Ltd | Banbury | 2016 |
| Arthropodservices Ltd | Bonnybridge | 2024 |
| Arthtech Ltd | Reading | 2022 |
| Arthur AI Limited | Dunstable | 2026 |
| Arthur and Hicks Resources UK Ltd | London | 2026 |
| Arthur and Martha Productions Limited | London | 2016 |
| Arthur App Ltd | London | 2026 |
| Arthur Ashe Advisory Services Limited | London | 2021 |
| Arthur Bean Sound Ltd | Blisworth | 2024 |
| Arthur Beeston Law Limited | Peterborough | 2022 |
| Arthur Davis Ltd | Gerrards Cross | 2018 |
| Arthur Design Ltd | London | 2013 |
| Arthur Financial Technologies Ltd | London | 2026 |
| Arthur Fleming & Co. Limited | London | 2019 |
| Arthur Grosvenor & Co Limited | Waterlooville | 2015 |
| Arthur H.Stockwell,Limited | Luton | 1925 |
| Arthur J Wade Ltd | London | 2024 |
| Arthur James Limited | London | 1995 |
| Arthur Loveday Cinematography Limited | London | 2019 |
| Arthur M. Limited | Wigton | 2011 |
| Arthur M.C. Ltd | Wareham | 2025 |
| Arthur Marketing Limited | Cardiff | 2013 |
| Arthur Martin Keegan Consultancy Ltd | Burton-On-Trent | 2016 |
| Arthur Online Limited | London | 2012 |
| Arthur Phoenix Limited | London | 2023 |
| Arthur Rabbit Limited | London | 2026 |
| Arthur Rose Solutions Limited | Lytham | 2011 |
| Arthur Street Films Limited | Belfast | 2015 |
| Arthur Thomas Ltd | Rochdale | 2025 |
| Arthur Victor Ltd | Watford | 2008 |
| Arthur Voyage Ltd | London | 2025 |
| Arthur Wooster Ltd | London | 2015 |
| Arthur's LAB Ltd | Stoke On Trent | 2026 |
| Arthur's Seat Limited | Harrow | 2021 |
| Arthur, Arthur and Company Limited | Plymouth | 2025 |
| Arthurguy.Co.Uk Ltd | Hastings | 2011 |
| Arthurian Games Ltd | Birmingham | 2022 |
| Arthurian-Labs.Ai Limited | Swindon | 2025 |
| Arthy Technologies Limited | Slough | 2012 |
| Arthyconsulting Ltd | Aylesbury | 2019 |
| Arti Braude Ltd | London | 2023 |
| Arti Education Ltd | London | 2025 |
| Arti Languages Ltd | London | 2023 |
| Artiax Ltd | London | 2019 |
| Artibod Limited | Fareham | 2009 |
| Artic Wolf Ltd | Dewsbury | 2025 |
| Artica Films Production Ltd | Liverpool | 2024 |
| Articad Limited | Watford | 1992 |
| Artical Heights Ltd | Greenford | 2017 |
| Articca Ltd | London | 2020 |
| Artichoke Films Ltd | London | 2026 |
| Artichoke Media Limited | Peterborough | 2023 |
| Artichokethemovie Limited | Worcester | 2018 |
| Articise Ltd | London | 2016 |
| Artickl Ltd | London | 2021 |
| Article 1 Productions Limited | London | 2020 |
| Article 27 Representation (UK) Limited | Maidstone | 2019 |
| Article 37 (Data Protection Officer) Services (UK) Limited | Maidstone | 2019 |
| Article AI Ltd | Salford | 2024 |
| Article Seven Limited | Sidcup | 2006 |
| Articleboy Limited | Middlesex | 2021 |
| Articon Consulting Ltd. | London | 2017 |
| Articqo Ltd | London | 2019 |
| Articsoft Technologies Limited | Exeter | 2005 |
| ARTICUL8 Media Limited | Bury St Edmunds | 2024 |
| Articulate (London) Ltd | Bury St. Edmunds | 2011 |
| Articulate Advisory Limited | Birmingham | 2015 |
| Articulate Associates Ltd | London | 2019 |
| Articulate Communications Agency Ltd | London | 2005 |
| Articulate Concepts Ltd | Bury St. Edmunds | 2021 |
| Articulate Digital Ltd | Bristol | 2018 |
| Articulate Hrms Consulting Limited | Cambridge | 2010 |
| Articulate LDN Limited | London | 2025 |
| Articulate Music Limited | London | 2015 |
| Articulate Pictures Ltd. | London | 1991 |
| Articulate Profile Solutions Limited | London | 2019 |
| Articulate Technology Limited | Peterborough | 2011 |
| Articulate.Xyz Ltd | Stoke-On-Trent | 2017 |
| Articulated AI Ltd | London | 2023 |
| Articulated Productions Limited | London | 2008 |
| Articulated Studio Ltd | Clerkenwell | 2017 |
| Articura Ltd | London | 2026 |
| Articus Insights Limited | Newton Aycliffe | 2026 |
| Articus Media Ltd | London | 2017 |
| Artifact AI Ltd | London | 2024 |
| Artifact Art Limited | Horsham | 2021 |
| Artifact Entertainment Limited | Horsham | 2021 |
| Artifact Films Ltd | London | 2022 |