| J & C Howarth (Wholesale) Limited | Wholesale & retail | 1985 |
| J & HM Services Limited | Construction | 2012 |
| J & Z Property Education Ltd | Education | 2024 |
| J C Couriers Ltd | Transport & logistics | 2025 |
| J Dowd Electrical Solutions Limited | Construction | 2011 |
| J E & P J Porter Shop Fitters Limited | Construction | 2005 |
| J E O'Halloran Electrical Contractors LLP | | 2005 |
| J LEE Engineering Services Ltd | Professional & scientific | 2024 |
| J N P Refurbishments Ltd | Manufacturing | 2023 |
| J Priestley Transport Limited | Transport & logistics | 2000 |
| J S H Plastering Services Limited | Construction | 2020 |
| J T Car Sales Worksop Ltd | Wholesale & retail | 2016 |
| J Wood Holdings Ltd | Health & social care | 2022 |
| J&L HGV Services Ltd | Wholesale & retail | 2024 |
| J&M Engineering Ltd | Professional & scientific | 2024 |
| J&Z Property Solutions Ltd | Real estate | 2018 |
| J.A.P. Installations Ltd | Construction | 2018 |
| J.C.M. Glassford (Holdings) Limited | Agriculture & fishing | 2017 |
| J.J.K Project Management Ltd | Construction | 2011 |
| J.O.E Solar Ltd | Construction | 2022 |
| J.P. Foot Surgery Ltd | Health & social care | 2003 |
| Jackson Accountancy Limited | Extraterritorial | 2017 |
| James Bradley Electrical UK Ltd | Construction | 2023 |
| Jason David Ltd | Other services | 2021 |
| Jateg Ltd | Hospitality | 2025 |
| JAY and SON Haulage Ltd | Transport & logistics | 2016 |
| JAY Systems Limited | Information & communication | 2016 |
| Jaycee`S PCS Ltd | Information & communication | 2006 |
| Jaytec Innovation Ltd | Construction | 2025 |
| JB Plumbing Heating and Property Maintenance Ltd | Construction | 2025 |
| JBS Properties (Yorkshire) Limited | Real estate | 2026 |
| JC Joinery & SON Ltd | Construction | 2023 |
| JCH Safety Training and Consultancy Ltd | Education | 2021 |
| JCK Property Investments Limited | Real estate | 2017 |
| JCP Shires Ltd | Manufacturing | 2021 |
| JCR Rescue & Recovery Ltd | Wholesale & retail | 2023 |
| JD Properties (Liverpool) Ltd | Hospitality | 2022 |
| JDB Installations Ltd | Construction | 2019 |
| JDCLEARANCE1 Ltd | Wholesale & retail | 2025 |
| Jdmm Investments Ltd | Arts & recreation | 2026 |
| JDW7 Limited | Professional & scientific | 2020 |
| Jessica MEE Limited | Other services | 2019 |
| JET Pro Solutions Ltd | Administrative & support | 2026 |
| JEZ Driving Ltd | Transport & logistics | 2019 |
| JF & Sons Ltd | Construction | 2022 |
| JIB273 Ltd | Transport & logistics | 2020 |
| JJ Simply Worksop Limited | Wholesale & retail | 2026 |
| Jjbr Limited | Construction | 2014 |
| JJK Transport Ltd | Transport & logistics | 2024 |
| JJW Automotives Ltd | Wholesale & retail | 2025 |
| Jjwhite Consultancy Limited | Health & social care | 2026 |
| Jkcp Limited | Hospitality | 2024 |
| JLH Cleaning Ltd | Administrative & support | 2023 |
| JLN Family Law Ltd | Professional & scientific | 2018 |
| JM Fellows & Sons Ltd | Transport & logistics | 2025 |
| JMG Brickwork Limited | Construction | 2009 |
| JML Coaching and Consulting Ltd | Professional & scientific | 2022 |
| JMR Racing Limited | Wholesale & retail | 2020 |
| Jmvi Healthcare Limited | Health & social care | 2018 |
| JND Risk Management Services Ltd | Professional & scientific | 2025 |
| JO Sweetnam Financial Consultant Limited | Professional & scientific | 2022 |
| JOE Ashley Brickwork Ltd | Construction | 2024 |
| JOE Dean Golf Limited | Other services | 2024 |
| John Benson Contract Services Limited | Construction | 1997 |
| John Bint Limited | Real estate | 1982 |
| John Bishop Construction Limited | Construction | 2002 |
| John Paine Limited | Transport & logistics | 2018 |
| John Short Engineering Limited | Professional & scientific | 2018 |
| John Whitehead Plumbing and Heating Limited | Construction | 2019 |
| John Whittington & SON Ltd | Manufacturing | 2017 |
| Johnsons Homes Limited | Construction | 2020 |
| Jolis PUB Company Ltd | Hospitality | 2024 |
| Joma PI Ltd | Administrative & support | 2025 |
| Jones & Rees Ltd. | Administrative & support | 2022 |
| Jopretem Global Ltd | Wholesale & retail | 2022 |
| Josel Limited | Real estate | 2025 |
| JP Autotechnics Ltd | Wholesale & retail | 2002 |
| JP Fire Safety Solutions Ltd | Administrative & support | 2019 |
| JR Mobile Mech Ltd | Wholesale & retail | 2025 |
| JRS Worksop Limited | Hospitality | 2025 |
| JS Carlton Road News Ltd | Wholesale & retail | 2022 |
| JT Change Management Ltd | Construction | 2014 |
| JT Executive Travel Ltd | Transport & logistics | 2019 |
| JT Mitchell Construction Ltd | Construction | 2019 |
| JTM Companies Ltd | Hospitality | 2014 |
| Jubilee Electronics Limited | Manufacturing | 1976 |
| Jubilee Microsystems Limited | Manufacturing | 1979 |
| Judge Family Investment Company Limited | Real estate | 2021 |
| Julie Leigh Properties Limited | Real estate | 2020 |
| Julka Transport Ltd | Transport & logistics | 2019 |
| JV Properties (Southern) Limited | Real estate | 2021 |
| JWC Electrical Services Ltd | Construction | 2025 |
| JZR Investments Ltd | Real estate | 2024 |
| Jzrb Property Limited | Real estate | 2019 |
| K & K Property Investments (Worksop) Limited | Real estate | 2026 |
| K C Sofas Limited | Wholesale & retail | 2015 |
| K M Greveson Holdings Limited | Construction | 2024 |
| K W Beever Commercial Interiors Ltd | Construction | 2020 |
| K&A Spectrum Ltd | Construction | 2025 |
| K&L Studios Ltd | Information & communication | 2024 |