| J.B.Slater Ltd | Wholesale & retail | 2024 |
| J.C Tree Care & Services Limited | Administrative & support | 2024 |
| J.C.T. 600 (Bradford) Limited | Professional & scientific | 1985 |
| J.C.T. 600 (Hull) Limited | Extraterritorial | 1987 |
| J.C.T. 600 (Leeds) Limited | Extraterritorial | 1963 |
| J.C.T. 600 (Wakefield) Limited | Extraterritorial | 1914 |
| J.C.T. 600 (Yeadon) Limited | Extraterritorial | 1929 |
| J.D.P Fire and Security (BFD) Limited | Administrative & support | 2024 |
| J.D.P. Electrical Solutions Limited | Construction | 2007 |
| J.G Home Interiors Limited | Wholesale & retail | 2025 |
| J.G Properties (Yorkshire) Ltd | Real estate | 2020 |
| J.H. Clissold & SON Ltd. | Manufacturing | 1975 |
| J.H.Cockroft(Exports)Limited | Professional & scientific | 1969 |
| J.H.Cooper & Son(Ilkley)Limited | Professional & scientific | 1954 |
| J.Jays Estates Limited | Other services | 2013 |
| J.Long & Sons(Haulage)Limited | Transport & logistics | 1961 |
| J.M.S Stone Mason Builders Ltd | Construction | 2023 |
| J.P.K Security Solutions Ltd | Administrative & support | 2023 |
| J.R. LTU Ltd | Transport & logistics | 2019 |
| J.R.M Plumbing & GAS Limited | Construction | 2016 |
| J.S Construction & Development Ltd | Construction | 2024 |
| J.S Equipment Ltd | Manufacturing | 2024 |
| J.S.R. BFD Properties Limited | Real estate | 2018 |
| J3M Ltd | Real estate | 2023 |
| J9 Prestige Limited | Wholesale & retail | 2021 |
| JA Banq Ltd | Hospitality | 2025 |
| JA Groundworks and Construction Ltd | Construction | 2020 |
| JA Private Ltd | Administrative & support | 2018 |
| JA UK Enterprise Limited | Administrative & support | 2024 |
| JA UK Properties Ltd | Hospitality | 2026 |
| Jaai Creative World Ltd | Information & communication | 2026 |
| Jaan Real Estate Ltd | Real estate | 2023 |
| Jaat Services Ltd | Transport & logistics | 2026 |
| Jabm Academy Ltd | Other services | 2025 |
| Jacey Construction Limited | Construction | 2025 |
| Jack & Family Ltd | Transport & logistics | 2018 |
| Jack Pennington Limited | Wholesale & retail | 1974 |
| Jacks House Birstall Limited | Hospitality | 2018 |
| Jackson Bowen Ltd | Wholesale & retail | 2020 |
| Jackson Foot Bliss Limited | Health & social care | 2023 |
| Jackson Hygienists Ltd | Health & social care | 2013 |
| Jacksons Retreats Ltd | Hospitality | 2025 |
| Jacob & Co Properties Ltd. | Real estate | 2018 |
| Jacob QSR Ltd | Hospitality | 2023 |
| Jacobs Motorhouse Limited | Wholesale & retail | 2019 |
| Jacobs Online Limited | Wholesale & retail | 2020 |
| Jacobson Courier Services Limited | Transport & logistics | 2025 |
| Jade Garden Bradford Limited | Hospitality | 2026 |
| Jade Kylin Ltd | Hospitality | 2025 |
| Jade Taverns Ltd | Hospitality | 2023 |
| Jadecurve Ltd | Wholesale & retail | 2025 |
| Jadegardeninclayton Ltd | Hospitality | 2026 |
| Jades Chinese Takeaway Ltd | Hospitality | 2026 |
| Jadore Banqueting Limited | Hospitality | 2025 |
| Jadore Deli & Bakery Ltd | Hospitality | 2026 |
| Jae's Roa[Story] Limited | Wholesale & retail | 2023 |
| JAF Rectifier Specialists Limited | Administrative & support | 1980 |
| Jaffa Marketing Limited | Professional & scientific | 2018 |
| Jagdeep SINGH2 Ltd | Construction | 2025 |
| Jagger Construction Ltd | Construction | 2025 |
| Jagger Media Limited | Information & communication | 2013 |
| Jagoda Catering Ltd | Hospitality | 2015 |
| Jahangir Builders Ltd | Construction | 2019 |
| Jahangir Estates Ltd | Real estate | 2025 |
| Jahedul Enterprises Ltd | Wholesale & retail | 2025 |
| Jahs Investments Ltd | Real estate | 2025 |
| JAI DEE Autos Ltd | Construction | 2013 |
| Jail Kitchen Ltd | Hospitality | 2026 |
| Jaisimran Boutique Ltd | Wholesale & retail | 2025 |
| Jaja Enterprise Ltd | Wholesale & retail | 2020 |
| Jaja Motors Ltd | Wholesale & retail | 2020 |
| Jak's Windows Ltd | Administrative & support | 2025 |
| Jakes Bakehouse Kiosk Ltd | Wholesale & retail | 2025 |
| Jakes Bakehouse Ltd | Wholesale & retail | 2025 |
| JAL Moorhouse Limited | Financial services | 2015 |
| Jaldi Jaldi Chai Ltd | Other services | 2019 |
| Jalwa Properties Limited | Hospitality | 2020 |
| Jalwa Weddings Limited | Hospitality | 2013 |
| JAM Packaging (AM) Ltd | Wholesale & retail | 2019 |
| Jamal Adam Limited | Wholesale & retail | 2023 |
| Jambrick Ltd | Professional & scientific | 2023 |
| James Bowmer Ltd | Real estate | 2018 |
| James Dusan Pubco Limited | Hospitality | 2024 |
| James Faaris Properties Ltd | Real estate | 2024 |
| James Harry Temple Ltd | Transport & logistics | 2026 |
| James Heffy Limited | Construction | 2017 |
| James Hughes Consulting Limited | Professional & scientific | 2025 |
| James Reckitt Properties Limited | Construction | 2021 |
| James Robinson Fibres Limited | Manufacturing | 1944 |
| James Swain Electrical Services Limited | Construction | 2006 |
| James Wimpenny Homes Limited | Construction | 1998 |
| James-Harrison Joinery Limited | Construction | 2016 |
| James@Parker Ltd | Energy | 2021 |
| Jamia Ya-Rasool Allah Limited | Health & social care | 2016 |
| Jamiyat Tabligh-Ul-Islam | Other services | 2011 |
| Jamjam Ltd | Professional & scientific | 2026 |
| Jamm Enterprises Limited | Hospitality | 2025 |
| Jammy Logistics Ltd | Transport & logistics | 2026 |
| Jampm Ltd | Extraterritorial | 2024 |
| Jamruth Catering Ltd | Hospitality | 2023 |