| J and a Murphy (Motor Vehicle Engineers) Limited | Wholesale & retail | 2005 |
| J and I Properties Limited | Real estate | 2020 |
| J C Mills & SON Limited | Construction | 2004 |
| J Cleaning Service Ltd | Administrative & support | 2025 |
| J Double E Properties Ltd | Real estate | 2024 |
| J F Rothwell Haulage Ltd | Transport & logistics | 2024 |
| J F Security Systems Ltd | Administrative & support | 2013 |
| J Farrell Developments Limited | Real estate | 2022 |
| J G Cladding Systems Limited | Construction | 2017 |
| J G Property Investments Limited | Real estate | 2021 |
| J Glover Transport Ltd | Administrative & support | 2018 |
| J Heritage Restoration & Renovation Ltd | Construction | 2026 |
| J Lawler Design Ltd | Professional & scientific | 2024 |
| J Magill Properties Ltd | Real estate | 2022 |
| J P Developments 25 Ltd | Construction | 2025 |
| J P Plastering & Rendering Ltd | Construction | 2025 |
| J S K Training Ltd | Administrative & support | 2012 |
| J T Home Improvements NW Ltd | Construction | 2021 |
| J&I Light Group Ltd | Wholesale & retail | 2019 |
| J&Kb Electrical Ltd | Construction | 2026 |
| J&R Rosca Ltd | Transport & logistics | 2019 |
| J&R Tree Services Ltd | Administrative & support | 2025 |
| J&S Property Developments Limited | Construction | 2025 |
| J'S Family Care Ltd | Health & social care | 2020 |
| J. a. Yates Construction Limited | Construction | 2002 |
| J. Blackledge & SON Limited | Extraterritorial | 2003 |
| J. Cooney Limited | Construction | 1986 |
| J. Glennon Construction Ltd | Construction | 2025 |
| J. O'Rourke Ltd | Professional & scientific | 2014 |
| J.A.K. Matterson Limited | Professional & scientific | 1992 |
| J.C. Mciver & Co. Limited | Professional & scientific | 1978 |
| J.D.O Services Ltd | Other services | 2021 |
| J.E.B. Educational Consultancy Limited | Education | 2003 |
| J.H. Temperley (Holdings) Limited | Financial services | 1950 |
| J.J.G Engineering Ltd | Manufacturing | 2025 |
| J.M. Roberts Limited | Manufacturing | 1971 |
| J.P. Waste Management & Recycling Ltd | Water & waste | 2019 |
| J.R. Ashworth & Sons Limited | Administrative & support | 1951 |
| J.R.S. Consulting Ltd. | Professional & scientific | 1999 |
| J.S Simm Civils and Groundwork’S Ltd | Construction | 2025 |
| J21 Ltd | Administrative & support | 2012 |
| JA Tech RD Ltd | Professional & scientific | 2026 |
| Jabal AL Rahma Ltd | Professional & scientific | 2023 |
| Jace Enterprises Ltd | Wholesale & retail | 2021 |
| Jack Spence Limited | Construction | 2024 |
| Jacko's Gym Ltd | Health & social care | 2022 |
| Jackson, Jackson & Sons Limited | Construction | 1991 |
| Jacksons Farm Fayre Ltd. | Wholesale & retail | 1997 |
| Jacob Kirk Visualisation Ltd | Professional & scientific | 2019 |
| Jade Alder Limited | Manufacturing | 2025 |
| Jade Rosales Services Limited | Health & social care | 2023 |
| Jaflas DR Alan Blacker & Co CIC | Information & communication | 2022 |
| Jahc Ltd | Professional & scientific | 2023 |
| JAI Events Limited | Hospitality | 2019 |
| Jajo Race Components Limited | Wholesale & retail | 2025 |
| Jalbal Ltd | Wholesale & retail | 2020 |
| JAM95 Ltd | Financial services | 2017 |
| Jamal Haulage Ltd | Transport & logistics | 2025 |
| James Campbell & Associates Limited | Construction | 2011 |
| James Campbell Associates Ltd | Construction | 2004 |
| James Campbell Holdings Ltd | Real estate | 2022 |
| James Campbell Properties Ltd | Real estate | 2021 |
| James Hartley Demolition (Lancaster)Limited | Wholesale & retail | 1971 |
| James Kelly Architects Limited | Professional & scientific | 2013 |
| James Kelly Investments Limited | Real estate | 2023 |
| James Swallow Limited | Administrative & support | 1941 |
| Jane Nottage Communications Limited | Administrative & support | 2010 |
| Jango Plumbing Services Ltd | Construction | 2026 |
| Janjua Dent Limited | Health & social care | 2024 |
| Jaraa Ltd | Professional & scientific | 2020 |
| Jarrah Furniture Ltd | Wholesale & retail | 2025 |
| Jarral Properties NW Ltd | Real estate | 2022 |
| Jasam Packaging Ltd | Administrative & support | 2025 |
| Jasjonev Ltd | Health & social care | 2022 |
| Jasu Property Ltd | Real estate | 2022 |
| JAV Tech Limited | Professional & scientific | 2012 |
| Javeds OFF Licence Ltd | Wholesale & retail | 2018 |
| Javman Ltd | Wholesale & retail | 2024 |
| Jawad Saleem Limited | Health & social care | 2015 |
| Jaws Mini Crushers UK Ltd | Administrative & support | 2022 |
| JAY Mccurdy Ltd | Arts & recreation | 2022 |
| Jazz Bargain Store Limited | Wholesale & retail | 2020 |
| JB Location Services Limited | Administrative & support | 2011 |
| JB PC Repairs Ltd | Information & communication | 2008 |
| Jbwtrades&Sales Ltd | Wholesale & retail | 2026 |
| JC Elite Coaching Ltd | Education | 2025 |
| JCK Consulting Ltd | Professional & scientific | 2025 |
| JCR Electrical Contractor Ltd | Construction | 2019 |
| JD Customs Ltd | Administrative & support | 2021 |
| JD Hampsons Ltd | Professional & scientific | 2025 |
| Jdab Electrical Services Limited | Manufacturing | 2014 |
| JDB Consultants Ltd. | Other services | 2021 |
| Jddc Entertainment Ltd | Information & communication | 2023 |
| JDH Spooks Paranormal Ltd | Administrative & support | 2021 |
| Jdlettingagent Limited | Real estate | 2024 |
| JDS North West Limited | Construction | 2019 |
| JDW Cleaning Solutions Ltd | Administrative & support | 2026 |
| Jecy Healthcare Services Limited | Health & social care | 2024 |
| Jedi Marketing Ltd | Wholesale & retail | 2025 |
| Jefferson Clarke Limited | Professional & scientific | 2025 |