| J & B Construction (Yorkshire) Ltd | Construction | 2009 |
| J & C Croysdale Limited | Professional & scientific | 2000 |
| J & D Fire Consultancy Limited | Professional & scientific | 2018 |
| J & E Plumbing & Heating Limited | Construction | 2007 |
| J & J Parkinson Ltd | Wholesale & retail | 2012 |
| J & M Heating Limited | Construction | 2012 |
| J & M Properties Services Limited | Real estate | 2024 |
| J & O Excavations Limited | Construction | 2006 |
| J & P Groundworks Ltd | Construction | 2024 |
| J and K Industries Limited | Construction | 2024 |
| J Aston Transport Ltd | Transport & logistics | 2020 |
| J B Faulkner Limited | Construction | 2012 |
| J Bamford Ltd | Information & communication | 2023 |
| J Barclay Medical Services Limited | Health & social care | 2017 |
| J Bell Investments Ltd | Real estate | 2023 |
| J Bird Ltd | Manufacturing | 2021 |
| J Blackburn & Sons Group Limited | Financial services | 2018 |
| J Blackburn & Sons Limited | Administrative & support | 2007 |
| J Britton Limited | Wholesale & retail | 2012 |
| J Brown & SON Limited | Wholesale & retail | 2002 |
| J C Electrical (Hemsworth) Limited | Construction | 2020 |
| J C Woodcock Ltd | Real estate | 2016 |
| J Clarke Construction Ltd | Construction | 2009 |
| J Commercials Limited | Real estate | 2025 |
| J Cosgrove Electrical Limited | Construction | 2014 |
| J Dafni Ltd | Wholesale & retail | 2023 |
| J Dove Property Group Ltd | Real estate | 2025 |
| J E Independent Consultancy Ltd | Health & social care | 2021 |
| J E Jenkins Ltd | Professional & scientific | 2025 |
| J E Shaw Limited | Administrative & support | 2022 |
| J Good Limited | Financial services | 2012 |
| J H Electrical Solutions Limited | Construction | 2017 |
| J H Hospitality Limited | Hospitality | 2014 |
| J H Milnes Holdings Limited | Other services | 2016 |
| J Haigh Ltd | Other services | 2016 |
| J Hepworth Fencing Limited | Construction | 2022 |
| J Hilton Decorating Contractors Ltd | Construction | 2026 |
| J Hilton Homes Limited | Real estate | 2023 |
| J J B Haulage Yorkshire Limited | Transport & logistics | 2015 |
| J J Services (Barnsley) Ltd | Real estate | 2020 |
| J L Kitchens & Joinery Limited | Construction | 2022 |
| J M Boxing Ltd | Arts & recreation | 2022 |
| J M Optics Limited | Wholesale & retail | 2004 |
| J M S Installations Ltd | Construction | 2009 |
| J Mitchell Joinery Limited | Other services | 2016 |
| J Moss Transport Limited | Transport & logistics | 2011 |
| J Outwin Electrical Contractors Ltd | Construction | 2016 |
| J P Davids Heat IT Ltd | Construction | 2004 |
| J P Fitzsimons Limited | Financial services | 2023 |
| J P N Renewable Heating Solutions Ltd | Construction | 2023 |
| J Plater Limited | Construction | 2016 |
| J R Ellam Properties Ltd | Real estate | 2025 |
| J R Engineering & Doors Ltd | Construction | 2020 |
| J R Norton Limited | Arts & recreation | 2003 |
| J Richardson Property Development Ltd | Real estate | 2022 |
| J S & Edgar Ltd | Real estate | 2022 |
| J S Fire & Security Ltd | Administrative & support | 2020 |
| J Swift Access Scaffolding Ltd | Construction | 2025 |
| J TEC Property Services Ltd | Real estate | 2021 |
| J TEC Services Ltd | Other services | 2019 |
| J W Boylin Group Limited | Transport & logistics | 1954 |
| J W Boylin Property Limited | Extraterritorial | 2004 |
| J W Property Portfolio Ltd | Real estate | 2025 |
| J Wallis Metals Ltd | Extraterritorial | 2016 |
| J Watson & SON Construction Ltd | Construction | 2025 |
| J&A Commercials Ltd | Manufacturing | 2024 |
| J&A Estates (Yorkshire) Ltd | Real estate | 2022 |
| J&E Family Property Ltd | Real estate | 2018 |
| J&E Moss Properties Ltd | Real estate | 2024 |
| J&M Innovations Ltd | Real estate | 2023 |
| J&T Solar Solutions Ltd | Construction | 2023 |
| J'S Hospitalities Limited | Hospitality | 2025 |
| J. Addy Builders Ltd | Construction | 2018 |
| J. Harris (Motor Bodies) Limited | Wholesale & retail | 1965 |
| J. Hole Limited | Construction | 2018 |
| J. Reekie Electrical Ltd | Construction | 2020 |
| J.A Flooring Contractors Ltd | Construction | 2022 |
| J.B.Kind Limited | Wholesale & retail | 2025 |
| J.B.U Utilities & Groundworks Ltd | Construction | 2023 |
| J.C Property Solutions Limited | Real estate | 2022 |
| J.D Promotions (Barnsley) Ltd | Arts & recreation | 2019 |
| J.D. Hanson Limited | Construction | 2012 |
| J.E. Theaker and SON Limited | Agriculture & fishing | 2003 |
| J.I. Locum Limited | Health & social care | 2024 |
| J.J.S Driving Limited | Other services | 2011 |
| J.P.D. Holdings(Leeds) Limited | Real estate | 1965 |
| J.S Project Management Limited | Construction | 2008 |
| J.S.S Installations Limited | Manufacturing | 1999 |
| J.T Tyre Imports Ltd | Wholesale & retail | 2022 |
| J.W.Automotive Limited | Manufacturing | 2014 |
| J18EHM Limited | Professional & scientific | 2025 |
| J29 Construction Ltd | Construction | 2023 |
| J36 Digital Ltd | Information & communication | 2022 |
| J4G Advisory Limited | Professional & scientific | 2025 |
| JA and GH Ltd | Hospitality | 2019 |
| JA Civils Ltd | Construction | 2021 |
| Jack Beadle PR Ltd | Professional & scientific | 2021 |
| Jack Doors Garage Door Specialists Limited | Construction | 2025 |
| Jack Elliott Groundworks Limited | Construction | 2013 |
| Jack Handley Ltd | Transport & logistics | 2025 |