| Jaldi Jaldi Ltd | Hospitality | 2010 |
| Jall Limited | Health & social care | 2013 |
| Jalp Investments Ltd | Real estate | 2020 |
| Jalsa Cuisine Ltd | Hospitality | 2026 |
| Jaluna Limited | Other services | 2007 |
| Jalwas Cottage Ltd | Hospitality | 2025 |
| JAM 3 UK Ltd | Administrative & support | 2017 |
| JAM AI Limited | Information & communication | 2025 |
| JAM Btob Ltd | Information & communication | 2025 |
| JAM Concrete Flooring Ltd | Construction | 2020 |
| JAM Controls Limited | Information & communication | 2011 |
| JAM Entertainment Ltd | Other services | 2013 |
| JAM Event Solutions Ltd. | Hospitality | 2014 |
| JAM FX Ltd | Information & communication | 2024 |
| JAM Photographic Limited | Professional & scientific | 2010 |
| JAM Rental Properties Ltd | Real estate | 2017 |
| Jamales Junction Limited | Wholesale & retail | 2017 |
| Jambam Limited | Real estate | 2022 |
| Jamef Ltd. | Health & social care | 2003 |
| James & Tatton Limited | Extraterritorial | 1951 |
| James Allen Paintings Limited | Arts & recreation | 2012 |
| James Bell Web Development Ltd | Information & communication | 2025 |
| James Boulton Management Services Ltd | Construction | 2023 |
| James Brown & Sons (Somerset) Limited | Financial services | 2003 |
| James Butler Arts Ltd | Arts & recreation | 2026 |
| James Carr Corporate Recovery Ltd | Professional & scientific | 2015 |
| James Chadwick and Sons Limited | Administrative & support | 1990 |
| James Charles Taylor Ltd | Professional & scientific | 2020 |
| James David Hasson Ltd | Professional & scientific | 2024 |
| James Davison Studio Limited | Arts & recreation | 2015 |
| James Dinsdale Limited | Wholesale & retail | 1920 |
| James Duggan Medical Ltd | Health & social care | 2021 |
| James Environmental Limited | Extraterritorial | 2002 |
| James Ernest Limited | Other services | 2015 |
| James Forster Urology Limited | Health & social care | 2018 |
| James Grant (Retail) Limited | Wholesale & retail | 2015 |
| James Grant Limited | Wholesale & retail | 2005 |
| James Hare Limited | Construction | 1902 |
| James Harvey Builders Limited | Construction | 2004 |
| James Hill Ventures Limited | Professional & scientific | 2015 |
| James Hogg Writer Limited | Arts & recreation | 2014 |
| James Jones@Bf Ltd | Wholesale & retail | 2015 |
| James Jordan Associates Limited | Information & communication | 2003 |
| James K Morgan Ltd | Professional & scientific | 2022 |
| James Kellett Motorsport Ltd | Education | 2021 |
| James Luca Ltd | Construction | 2014 |
| James Lupton Consultants Ltd | Other services | 2013 |
| James Matthew and SON Limited | Hospitality | 2015 |
| James Rose Consulting Ltd | Professional & scientific | 2024 |
| James Smith Architecture Limited | Professional & scientific | 2012 |
| James Turner Videography Ltd | Information & communication | 2025 |
| James Vickers Limited | Professional & scientific | 1930 |
| James Wade Homes Ltd | Construction | 2010 |
| James Ward Digital Coach Limited | Information & communication | 2010 |
| James Warren Delivery Ltd | Transport & logistics | 2026 |
| James Whitworth & Sons Limited | Transport & logistics | 1905 |
| James-Eston:Skerritt Limited | Extraterritorial | 2024 |
| Jameson & James Ltd | Administrative & support | 2025 |
| Jameson Consulting Engineers Ltd | Professional & scientific | 2007 |
| Jameson Kelly Limited | Health & social care | 2013 |
| Jamestown Analytics Limited | Information & communication | 2017 |
| Jamie Caunt Home Improvements Limited | Construction | 2019 |
| Jamie Fearn Taasc Limited | Administrative & support | 2023 |
| Jamie Jones-Buchanan Ltd | Arts & recreation | 2011 |
| Jamie York Consulting Ltd | Professional & scientific | 2018 |
| Jamie York Investments Ltd | Administrative & support | 2019 |
| Jamie York SPV 1 Ltd | Real estate | 2016 |
| Jamie York SPV 2 Ltd | Real estate | 2021 |
| Jamie York SPV 3 Ltd | Real estate | 2021 |
| Jamie York SPV 4 Ltd | Real estate | 2024 |
| Jamie York SPV 6 Ltd | Real estate | 2025 |
| Jamie's Aromatherapy Ltd | Other services | 2023 |
| Jamins Leeds Ltd | Administrative & support | 2026 |
| Jamjar Property Rentals Limited | Real estate | 2021 |
| Jammu and Kashmir Meat Shop Limited | Manufacturing | 2026 |
| Jamnat Bradford Limited | Real estate | 2025 |
| Jamnat Ltd | Real estate | 2019 |
| Jamnat Property Rentals Ltd | Real estate | 2022 |
| Jamrock Leeds Limited | Hospitality | 2022 |
| Jamtalk Logistics Ltd | Hospitality | 2024 |
| Jamyang Buddhist Centre Leeds | Education | 2005 |
| Jamz Deco Ltd | Construction | 2021 |
| JAN Auto Traders Ltd | Wholesale & retail | 2026 |
| Janakpes Ltd | Administrative & support | 2023 |
| Janan Sleep Ltd | Manufacturing | 2016 |
| Jandu Living Limited | Real estate | 2024 |
| Jane Bytheway Limited | Professional & scientific | 2014 |
| Jane Etty Wellbeing Services Ltd | Health & social care | 2020 |
| Jane Florence Ltd | Wholesale & retail | 2025 |
| Jane Hart Consulting Limited | Professional & scientific | 2008 |
| Jane Jardine Design Limited | Professional & scientific | 2013 |
| Jane Lawson Properties Limited | Real estate | 2012 |
| Jane Tomlinson Appeal | Other services | 2006 |
| Jane Wong Property Ltd | Real estate | 2021 |
| Janeafri Limited | Wholesale & retail | 2019 |
| Janeil Ltd | Other services | 2020 |
| Janet Walter Consulting Ltd | Professional & scientific | 2022 |
| Janette Landon Limited | Administrative & support | 2015 |
| Janice Colley Consulting Limited | Professional & scientific | 2013 |
| Janisbites Ltd | Hospitality | 2026 |