| JJM Rentals Ltd | Real estate | 2025 |
| JK Consultants (Wakefield) Limited | Professional & scientific | 2022 |
| JK Kids Home Education Ltd | Education | 2025 |
| JK Medical Solutions Ltd | Health & social care | 2023 |
| JK Outlet Limited | Wholesale & retail | 2025 |
| JK Pharma Services Ltd | Health & social care | 2021 |
| JK Property Development Group Limited | Real estate | 2022 |
| JK Signature Homes Ltd | Construction | 2025 |
| Jk&A Ltd | Real estate | 2024 |
| Jk&Sons-Demolition Ltd | Construction | 2025 |
| JK360 Events Ltd | Hospitality | 2024 |
| JKB Property Developments Ltd | Real estate | 2025 |
| Jkembroidery Limited | Manufacturing | 2025 |
| JKF Content & Editing Limited | Information & communication | 2016 |
| Jkhan Locum Ltd | Health & social care | 2022 |
| JKR (Yorkshire) Ltd | Other services | 2016 |
| JKS Driving Services Ltd | Transport & logistics | 2015 |
| Jksm Properties Ltd | Real estate | 2024 |
| Jksskiphire Ltd | Water & waste | 2024 |
| JL Health Ltd | Health & social care | 2022 |
| JL Retail Group Limited | Wholesale & retail | 2026 |
| Jl.Impact Limited | Construction | 2025 |
| JLB Wholesale Ltd | Wholesale & retail | 2024 |
| Jlcl Properties Ltd | Real estate | 2025 |
| JLE Marketing Ltd | Professional & scientific | 2014 |
| JLG Construction Ltd | Construction | 2025 |
| JLJ Plant Hire & Site Services Ltd | Administrative & support | 2016 |
| JLP Garden Revival Limited | Administrative & support | 2019 |
| JLP Property Revival Limited | Construction | 2023 |
| JLP PUB Enterprises Ltd | Hospitality | 2025 |
| JLP PUB Management Limited | Hospitality | 2024 |
| JLT Logistics Ltd | Transport & logistics | 2017 |
| JM Commercial Consultants Ltd | Other services | 2013 |
| JM Eco Solutions Ltd | Construction | 2025 |
| JM Grayshon Ltd | Construction | 2016 |
| JM Plant & Commercials Ltd | Wholesale & retail | 2023 |
| Jmaa Motors Ltd | Wholesale & retail | 2021 |
| Jmail Assets Limited | Real estate | 2007 |
| JMB Scaffolding Limited | Construction | 2001 |
| JMC Real Estate Ltd | Construction | 2024 |
| JMK Trading Limited | Wholesale & retail | 2022 |
| JML Logistics Ltd | Transport & logistics | 2020 |
| Jmmac Healthy Solution Ltd | Health & social care | 2014 |
| JMP Property Solutions Limited | Other services | 2013 |
| JMP Stores Limited | Wholesale & retail | 2013 |
| JMR Motor Enginneers Ltd | Wholesale & retail | 2024 |
| JMU Logistics Ltd | Professional & scientific | 2025 |
| JN Property Maintenance Ltd | Construction | 2017 |
| JN Supplies Ltd | Wholesale & retail | 2024 |
| JNN Metalworks Ltd | Manufacturing | 2022 |
| JNS Motor Spares Limited | Wholesale & retail | 2014 |
| JOB Done Cleaning Services Ltd | Administrative & support | 2019 |
| Jobbuzz Ltd | Administrative & support | 2024 |
| Jodies Pubs Ltd | Hospitality | 2026 |
| JOE Child Joinery Ltd | Manufacturing | 2026 |
| Joe's Holdings Ltd | Hospitality | 2026 |
| Joedem Integrated Services Ltd | Manufacturing | 2026 |
| Joeet UK Limited | Wholesale & retail | 2022 |
| John Bateman Limited | Real estate | 2018 |
| John Bibby Limited | Administrative & support | 2010 |
| John Britton Ltd | Wholesale & retail | 2021 |
| John Foster (1819) Limited | Extraterritorial | 2009 |
| John Hughes, Anthony George Hughes and Bernard Evans | | 1987 |
| John J Limited | Manufacturing | 2024 |
| John Loker Electrical Limited | Construction | 2001 |
| John Sylvester (Fasteners & Plastics) Limited | Wholesale & retail | 1966 |
| John Sylvester Engineering Company Limited | Wholesale & retail | 1964 |
| Johnbims Enterprise Ltd | Hospitality | 2025 |
| Johnson Textiles Ltd | Manufacturing | 2022 |
| Johnson's Cuisine Ltd | Hospitality | 2026 |
| Joiner Master Ltd | Construction | 2019 |
| Joinerywise Ltd | Manufacturing | 2022 |
| Joiya Limited | Information & communication | 2025 |
| Jojo Supermarket Limited | Wholesale & retail | 2026 |
| Joks ALE House Ltd | Hospitality | 2018 |
| Jolls Facilities Services Ltd | Administrative & support | 2026 |
| Jolly Nail & Spa Limited | Other services | 2025 |
| Jolly Twins Enterprise Limited | Health & social care | 2022 |
| Jomac Services Limited | Construction | 2022 |
| JON Carlo Performance Ltd. | Wholesale & retail | 2025 |
| Jonathan Hollowood Consulting Limited | Professional & scientific | 2026 |
| Jonathan Jacob Photography Limited | Professional & scientific | 2011 |
| Jonathan Lumb Limited | Information & communication | 2020 |
| Jonathan Silver Limited | Extraterritorial | 1976 |
| Jones Masonry Ltd | Construction | 2016 |
| Joppa Limited | Hospitality | 2010 |
| Jordan Homes & Investments Ltd | Real estate | 2025 |
| Jordan Hvac Ltd | Construction | 2023 |
| Jordan Marsden Property Services Limited | Construction | 2018 |
| Jordan Street Manchester Limited | Construction | 2019 |
| Jordani Ltd | Wholesale & retail | 2023 |
| Joseph Arnold & Co Limited | Extraterritorial | 1975 |
| Joseph Daly Cabinetmaker Ltd | Manufacturing | 2017 |
| Joseph Dawson (Cashmere) Limited | Extraterritorial | 2010 |
| Joseph Dawson (International) Limited | Extraterritorial | 2010 |
| Joseph Hoyle & SON Limited | Manufacturing | 1921 |
| Joseph Khera Property Management Limited | Households | 2019 |
| Joseph Levin (Textiles) Limited | Professional & scientific | 1981 |
| Joseph Lumb Limited | Extraterritorial | 2001 |
| Joseph's Event Catering Limited | Hospitality | 2022 |