| J Mobbs Construction Ltd | Construction | 2025 |
| J P Winstanley Ltd | Water & waste | 2019 |
| J S Visabelle Limited | Real estate | 2025 |
| J&D Catering Services Ltd | Hospitality | 2024 |
| J&I Estate Ltd | Real estate | 2025 |
| J&M Convenience Store Limited | Wholesale & retail | 2019 |
| J. Battersby Engineering Limited | Manufacturing | 2000 |
| J. Hodson & SON Limited | Manufacturing | 2003 |
| J. W. Whittle Limited | Professional & scientific | 1968 |
| J.A.W Plumbing & Underfloor Heating Limited | Construction | 2022 |
| J.H.S Enterprises Ltd | Wholesale & retail | 2022 |
| J.H.S Wholesale Product's Ltd | Wholesale & retail | 2023 |
| J.M.S Electrical and Building Services Ltd | Construction | 2024 |
| Jack & Track Autocentre Limited | Wholesale & retail | 2019 |
| Jack Houghton Developments Limited | Real estate | 2022 |
| Jackal Group Limited | Manufacturing | 2023 |
| Jacks Bar Ltd | Hospitality | 2023 |
| Jacob's Pallets & Packaging Limited | Wholesale & retail | 2025 |
| Jacobi Carbons Limited | Manufacturing | 1996 |
| Jade Automation Limited | Professional & scientific | 2015 |
| Jakar Mobile Services Ltd | Manufacturing | 2026 |
| James Mack Construction Ltd | Construction | 2025 |
| James Trucking UK Limited | Transport & logistics | 2007 |
| JAMIES12 Ltd | Hospitality | 2026 |
| Jasper UK Holdings Ltd | Financial services | 2025 |
| Jatir Homes Ltd | Real estate | 2026 |
| Jaws Motorcycles Ltd | Wholesale & retail | 2018 |
| Jaybee Leisure (Leigh) Limited | Arts & recreation | 2006 |
| Jaymax Uniform Shop Ltd | Wholesale & retail | 2015 |
| Jbls Consulting Limited | Professional & scientific | 2025 |
| JCP Branded Ltd | Wholesale & retail | 2021 |
| JD Driving Amaz Ltd | Wholesale & retail | 2025 |
| JDR Haulage Ltd | Transport & logistics | 2026 |
| Jefferson Financial Services Ltd | Financial services | 2020 |
| Jelhousing. Ltd | Real estate | 2024 |
| Jeramiah Ferrari Limited | Arts & recreation | 2012 |
| Jeshani OFF Licence Ltd | Wholesale & retail | 2023 |
| Jessica Megan Studios Ltd | Other services | 2018 |
| Jessica Payne Chiropractic Limited | Health & social care | 2013 |
| JET Infrastructure Ltd | Information & communication | 2025 |
| JET Network Solutions Ltd | Information & communication | 2014 |
| Jetflow Drainage Ltd | Construction | 2019 |
| Jetz Travel Ltd | Administrative & support | 2018 |
| Jewel Tanning Studio Ltd | Other services | 2024 |
| Jffam Limited | Real estate | 2025 |
| JG Care Services Limited | Health & social care | 2010 |
| JH Letters Ltd | Hospitality | 2024 |
| JH Rope Access Services Ltd | Professional & scientific | 2021 |
| JHL Property Holdings Ltd | Real estate | 2026 |
| Jhlh Limited | Health & social care | 2022 |
| JJ Harrison PVC Limited | Manufacturing | 2020 |
| JJ Harrison PVC Products Ltd | Other services | 2002 |
| JK Consulting UK Ltd | Professional & scientific | 2006 |
| JK Mentor Ltd | Wholesale & retail | 2023 |
| JK Sheet Metal & Fabrication Ltd | Manufacturing | 2026 |
| JKS Precision Plumbing Ltd | Construction | 2017 |
| JLR Transport Manager Services Ltd | Administrative & support | 2018 |
| JM Medical Care (Northwest) Ltd | Health & social care | 2022 |
| JM Scaffold Design Ltd | Professional & scientific | 2019 |
| JMS Direct Ltd | Transport & logistics | 2020 |
| Joch Consulting Limited | Mining & quarrying | 2017 |
| Jodie Reynolds Limited | Information & communication | 2024 |
| Joe's Zone Limited | Health & social care | 2019 |
| John Clark (Metal Boxes) Limited | Manufacturing | 2004 |
| John Mcgrath Associates Limited | Professional & scientific | 2006 |
| JOHNNY2211 Limited | Health & social care | 2023 |
| Johnson ARB Ltd | Administrative & support | 2018 |
| Johnson ARB Tree Services Ltd | Administrative & support | 2023 |
| Johnson Training Ltd | Education | 2015 |
| Joint Accounting Services Limited | Professional & scientific | 2019 |
| Jokari Holdings Ltd | Financial services | 2024 |
| Jones Potts Taylor Limited | Real estate | 2023 |
| Jordan Interior Services Ltd | Manufacturing | 2022 |
| JPS Design & Print Services Limited | Manufacturing | 2003 |
| JR Global Services Ltd | Professional & scientific | 2021 |
| Jr's Avacab Private Hire Ltd | Transport & logistics | 2025 |
| JS Surveying Associates Limited | Professional & scientific | 2006 |
| JSB Perfect Property's Ltd | Real estate | 2025 |
| Julesrules Property Holdings Limited | Real estate | 2026 |
| Julie Booth Ltd | Information & communication | 2024 |
| Juris Law Limited | Professional & scientific | 2023 |
| Jury Street MOT Centre Limited | Wholesale & retail | 2025 |
| Just on Hiring Ltd | Wholesale & retail | 2021 |
| Just Tech IT Limited | Information & communication | 2013 |
| JW Sales Ltd | Wholesale & retail | 2025 |
| JWS Golf Ltd | Wholesale & retail | 2021 |
| JZ Unit Limited | Transport & logistics | 2020 |
| K & C Grant (Smallbrook) Limited | Wholesale & retail | 2004 |
| K & D Leisure Services Ltd | Hospitality | 2024 |
| K Smart Sign Ltd | Manufacturing | 2015 |
| K&A Build- Design.Com Ltd | Real estate | 2014 |
| K&M Delivery Ltd | Transport & logistics | 2023 |
| K&M Property Maintenance Ltd | Construction | 2026 |
| K.V. Roscoe & SON Limited | Construction | 1975 |
| K9 Projects Limited | Construction | 2006 |
| Kaaj House of Hearts Ltd | Real estate | 2023 |
| Kallos Faces Ltd | Health & social care | 2025 |
| Kamo Kitchen Ltd | Hospitality | 2020 |
| Kanzan Capital Limited | Professional & scientific | 2016 |
| Kanzan Investment Limited | Extraterritorial | 2016 |