| J B Rural Services Ltd | Construction | 2012 |
| J G Arts Ltd | Wholesale & retail | 2017 |
| J G Howard Limited | Construction | 2003 |
| J G S Consultants Limited | Health & social care | 2016 |
| J Glews Building Ltd | Construction | 2020 |
| J J H Commercial Properties Limited | Professional & scientific | 2013 |
| J K F Precision Engineering Limited | Manufacturing | 2006 |
| J L Developments & Sons Ltd | Construction | 2024 |
| J Noble Logistics and Consultancy Ltd | Professional & scientific | 2026 |
| J P Conveyors Ltd | Manufacturing | 2009 |
| J Smtih Holdings Limited | Real estate | 2026 |
| J T FOX Homes Limited | Real estate | 2025 |
| J T FOX Property Limited | Real estate | 2024 |
| J Wardle Transport Ltd | Transport & logistics | 2005 |
| J.L. Gladwin Farms Limited | Agriculture & fishing | 1985 |
| J.Muldoon Property Investments Limited | Real estate | 2024 |
| J.Owen Day.Limited | Agriculture & fishing | 1958 |
| J.P. Services (Lincs) Ltd | Administrative & support | 2011 |
| J.P.A. Dickinson Farms Limited | Agriculture & fishing | 1969 |
| J.P.A. Dickinson Ltd | Real estate | 2004 |
| J6 Design Ltd | Professional & scientific | 2015 |
| Jack Croule Plumbing Services Ltd | Construction | 2026 |
| Jack Darcy Ltd | Wholesale & retail | 2020 |
| Jack Davy Holdings Limited | Financial services | 2024 |
| Jackson & Lacey Construction Limited | Construction | 2019 |
| Jackson & Lacey Developments Limited | Real estate | 2018 |
| Jackson & Lacey Holding Limited | Real estate | 2016 |
| Jacksscrap Limited | Wholesale & retail | 2026 |
| JAE Autos Ltd | Wholesale & retail | 2024 |
| Jaime’S GET Active Stay Active CIC | Arts & recreation | 2024 |
| James Given Racing Limited | Administrative & support | 1998 |
| Jane Boyes Limited | Administrative & support | 2024 |
| Jarri Group Ltd | Wholesale & retail | 2020 |
| JB Referrals Ltd | Professional & scientific | 2010 |
| JBM Stone Development Ltd | Construction | 2025 |
| JBP Technical Services Ltd | Manufacturing | 2024 |
| JBS Lettings Ltd | Real estate | 2021 |
| Jcdev Ltd | Information & communication | 2026 |
| JCJ Health & Safety Ltd | Professional & scientific | 2017 |
| JDM Innovations Ltd | Real estate | 2025 |
| JDMS001 Ltd | Construction | 2025 |
| Jeans & SON Electrical Ltd | Construction | 2026 |
| Jellinek Properties Ltd | Real estate | 2022 |
| Jennifer Taylor Flying Well Limited | Transport & logistics | 2019 |
| Jeremy Hall (Plumber) Ltd | Construction | 2016 |
| Jet's Healthcare Ltd | Health & social care | 2022 |
| Jetstage Ltd | Transport & logistics | 2022 |
| JEY Trading Ltd | Wholesale & retail | 2025 |
| JG Beck Engineering Ltd | Construction | 2024 |
| JH Smithson & SON Limited | Construction | 2003 |
| JJ Care & Service Limited | Health & social care | 2021 |
| JJB Trans Limited | Transport & logistics | 2015 |
| JJG Property Holdings Ltd | Real estate | 2026 |
| JJR Media Ltd | Professional & scientific | 2025 |
| JK Cabs (Gainsborough) Ltd | Transport & logistics | 2017 |
| JKF Property Limited | Real estate | 2012 |
| Jmfitt Ltd | Arts & recreation | 2026 |
| JNC Electrical Contractors Ltd | Construction | 2024 |
| JO Wolfe Ltd | Wholesale & retail | 2017 |
| Joanne Lesley Carter Limited | Extraterritorial | 2025 |
| JOB Build Limited | Construction | 2003 |
| John Owens Associates Ltd | Information & communication | 2013 |
| Johnson Family Investment Holdings Limited | Financial services | 2024 |
| Johnson's Traditional Fish & Chips Limited | Hospitality | 2012 |
| Jonathan Lechmere Lawn Care and Maintenance Ltd | Professional & scientific | 2024 |
| Jones Carpentry and Construction Ltd | Construction | 2026 |
| Josa Renewables Ltd | Construction | 2025 |
| Josa-Ac Services Ltd | Construction | 2020 |
| Jowett Properties Limited | Real estate | 2024 |
| Joyfulhand Group Ltd | Wholesale & retail | 2025 |
| JPL Construction Limited | Construction | 2008 |
| JR Green Build Ltd | Construction | 2018 |
| JR Mindset Mastery Ltd | Health & social care | 2022 |
| Jrbc Consultancy Ltd | Professional & scientific | 2025 |
| Jrbc Install & Servicing Ltd | Construction | 2025 |
| Juan Pedro Ceconi DE Martiis Limited | Health & social care | 2023 |
| Judges Pies Ltd | Wholesale & retail | 2025 |
| Jujhar Property Holdings Ltd | Real estate | 2024 |
| Juniper Telecom Limited | Information & communication | 2010 |
| Juniper Violet Educational Psychology Services Ltd | Education | 2023 |
| JYT Site Services Ltd | Manufacturing | 2024 |
| K & J Muir Properties Ltd | Real estate | 2018 |
| K & M Goodlad Limited | Professional & scientific | 2026 |
| K Kami Limited | Other services | 2023 |
| K Neal Electrical Limited | Construction | 2006 |
| K Slack Glass & Glazing Ltd | Construction | 2020 |
| K&S Construction (London) Ltd | Construction | 2024 |
| K2 Kleaning Limited | Administrative & support | 2012 |
| KAL Designs Limited | Information & communication | 2010 |
| KAL Digital Group Holdings Limited | Wholesale & retail | 2014 |
| KAL Property Holdings Limited | Real estate | 2020 |
| Kamnath OFF Licence Ltd | Wholesale & retail | 2019 |
| Kanber Electrics Limited | Construction | 2026 |
| Kandy Hero Limited | Wholesale & retail | 2025 |
| Kane Developments (Gainsborough) Limited | Construction | 2004 |
| Karen Creed Travel Ltd | Administrative & support | 2026 |
| Karnival Costumes UK Limited | Wholesale & retail | 2019 |
| Karolina Dynasty Ltd | Hospitality | 2019 |
| Kayper Fence Ltd | Construction | 2023 |
| Kbvi Pipework Ltd | Professional & scientific | 2022 |