| J & D Infrastructure Ltd | Construction | 2021 |
| J & L Wright Limited | Real estate | 2020 |
| J & M Building & Developments Limited | Administrative & support | 2022 |
| J & M Services (Rotherham) Limited | Transport & logistics | 2019 |
| J & M Taxis Limited | Transport & logistics | 2012 |
| J & O Resources Ltd | Construction | 2015 |
| J & R Jewels Limited | Wholesale & retail | 2015 |
| J a Fletcher Developments Ltd | Construction | 2023 |
| J a Fletcher Group Ltd | Wholesale & retail | 2018 |
| J a Fletcher Ltd | Construction | 2016 |
| J a Fletcher Timber & Builders Merchants Ltd | Wholesale & retail | 2025 |
| J a Sutton Limited | Professional & scientific | 2012 |
| J Amina Consultancy Limited | Professional & scientific | 2019 |
| J B Doors Holdings Limited | Wholesale & retail | 2007 |
| J B Doors Limited | Wholesale & retail | 1999 |
| J Bestwick Tutoring & Teaching Services Limited | Education | 2019 |
| J Brown Carpentry Limited | Manufacturing | 2026 |
| J Burgin Limited | Construction | 2017 |
| J Burrows Plumbing & Heating Ltd | Construction | 2018 |
| J Cooke Properties Ltd | Real estate | 2023 |
| J D Plant Pipework Ltd | Construction | 2013 |
| J D Rigging Services Limited | Construction | 2015 |
| J D Rigging Specialists Limited | Extraterritorial | 2018 |
| J Dale Construction Management Limited | Construction | 2015 |
| J Dugdale Consultancy Ltd | Professional & scientific | 2025 |
| J E Brown Rentals Limited | Real estate | 2022 |
| J Fall Electrical Limited | Construction | 2016 |
| J FAM Investment UK Ltd | Other services | 2023 |
| J Garfitt & Co Limited | Professional & scientific | 2018 |
| J Gundry Plumbing & Heating Ltd | Construction | 2013 |
| J H Cars Rotherham Limited | Administrative & support | 2020 |
| J J C Trans Ltd | Transport & logistics | 2018 |
| J K Builders (Rotherham) Limited | Construction | 2017 |
| J K Building Services (Doncaster) Limited | Construction | 2021 |
| J L Green Lane Properties Limited | Real estate | 2009 |
| J L Hunter Ltd | Construction | 2018 |
| J L Parkinson Plastering Ltd | Construction | 2025 |
| J Love Ltd | Construction | 2021 |
| J M Ross Construction Ltd | Construction | 2017 |
| J M Select Properties Limited | Real estate | 2017 |
| J Mack Transport Limited | Transport & logistics | 2025 |
| J Newsam & Co Ltd | Professional & scientific | 2012 |
| J P Glasby Limited | Construction | 2004 |
| J Parks Plumbing and Heating Ltd | Construction | 2025 |
| J R Cleaning Services Limited | Administrative & support | 2023 |
| J R F Dunka Limited | Administrative & support | 2025 |
| J R Rendering Limited | Construction | 2022 |
| J R Whinfrey (Developments) Ltd | Construction | 2021 |
| J R Whinfrey Group Ltd | Financial services | 2021 |
| J R Whinfrey Ltd | Construction | 2015 |
| J Race Consultancy Limited | Professional & scientific | 2016 |
| J Roberts Design Ltd | Professional & scientific | 2014 |
| J Roper Plumbing & Heating Limited | Construction | 2012 |
| J S C Properties Ltd | Real estate | 2016 |
| J Saunders & SON (Maltby) LLP | | 2018 |
| J Squared Electrical Engineering Ltd | Construction | 2021 |
| J T Howe Plumbing & Heating Ltd | Construction | 2012 |
| J to B Rail Services Ltd | Construction | 2021 |
| J V Tilers Limited | Construction | 1999 |
| J W Associates (Maltby) 2013 Ltd | Professional & scientific | 2013 |
| J Walton Joinery Limited | Construction | 2024 |
| J Warcup Construction Ltd | Construction | 2023 |
| J Wright Group Ltd | Construction | 2026 |
| J Wright Property Management Ltd | Real estate | 2025 |
| J&C Plastering Ltd | Construction | 2025 |
| J&D Leisure and Entertainment Ltd | Hospitality | 2021 |
| J&I Goleniewski Ltd | Transport & logistics | 2023 |
| J&J Decorators Limited | Construction | 2000 |
| J&J Properties 2025 Ltd | Real estate | 2025 |
| J&L Roofing & Property Maintenence Ltd | Construction | 2026 |
| J&L Singhs Limited | Wholesale & retail | 2023 |
| J&P Management Ltd | Information & communication | 2019 |
| J&P Restaurant and Bar Ltd | Wholesale & retail | 2025 |
| J&S Venture Capital Holdings Ltd | Information & communication | 2018 |
| J&S Window and Guttering Specialists Ltd | Construction | 2025 |
| J&Z Property Ltd | Real estate | 2025 |
| J'S Fried Chicken Ltd | Hospitality | 2023 |
| J-Lock Enterprises Ltd | Financial services | 2016 |
| J-Mac Engineering Limited | Professional & scientific | 2001 |
| J. E. & L. Mellor Ltd | Other services | 2007 |
| J. G. Clifford & Co. Ltd | Real estate | 1992 |
| J.Goodson Electrical Limited | Construction | 2017 |
| J.H.& Developments Limited | Construction | 2006 |
| J.L.L. Drywall Limited | Construction | 2024 |
| J.T. Allott & SON Limited | Professional & scientific | 1993 |
| J.Vine & Sons Rental Properties Ltd | Real estate | 2026 |
| J4 Electrical Ltd | Construction | 2021 |
| J4 Group Ltd | Financial services | 2025 |
| JA Continuum LLP | | 2017 |
| JA Contract Flooring Ltd | Construction | 2025 |
| Ja&Aa Properties Ltd | Real estate | 2022 |
| JAC Sport Limited | Professional & scientific | 2011 |
| Jack Glossop Engineering Limited | Information & communication | 2023 |
| Jack&Tom FS Ltd | Financial services | 2020 |
| Jacko’S Empire Ltd | Water & waste | 2025 |
| Jackson Joinery Solutions Ltd | Construction | 2021 |
| Jackson Maintenance Services UK Ltd | Manufacturing | 2020 |
| Jackson Rail Solutions Ltd | Manufacturing | 2016 |
| Jackson Transport (Wath) Limited | Transport & logistics | 2017 |
| Jackson Westville Limited | Hospitality | 2014 |