| JEH Engineering Limited | Professional & scientific | 2019 |
| JEJ Engineering Limited | Professional & scientific | 2018 |
| JEJ444 Ltd | Financial services | 2024 |
| Jellkh Ltd | Health & social care | 2021 |
| JEM Catering & Events Ltd | Hospitality | 2018 |
| JEM HR Consultancy Ltd | Administrative & support | 2026 |
| Jemilios Limited | Hospitality | 2025 |
| Jemstadt Ventures Ltd | Health & social care | 2024 |
| Jemworks Limited | Professional & scientific | 2017 |
| Jena Developments Limited | Construction | 2018 |
| Jennifer Hynes Quality Consultancy Limited | Professional & scientific | 2025 |
| JENNIFERCREATIVES247 Limited | Wholesale & retail | 2025 |
| Jennings K9 Limited | Agriculture & fishing | 2022 |
| Jennor & Co. Limited | Professional & scientific | 2004 |
| Jenny Wren's Ceramics and Coffee Ltd | Hospitality | 2012 |
| Jensen Investments Limited | Real estate | 1999 |
| Jepson Brothers Limited | Agriculture & fishing | 2003 |
| Jera Management Limited | Administrative & support | 2007 |
| Jeremy Newman Design Limited | Administrative & support | 2014 |
| Jessann Projects Ltd | Administrative & support | 2021 |
| Jessica Kate Ltd | Administrative & support | 2024 |
| Jessica Spokes Limited | Administrative & support | 2023 |
| Jessica Tamsin Consulting Ltd | Professional & scientific | 2025 |
| JET Commercial Vehicle Repairs Ltd | Administrative & support | 2026 |
| JET Homes and Properties Ltd | Real estate | 2024 |
| JET Technical Services Limited | Professional & scientific | 2017 |
| Jetfix Servicing Ltd | Manufacturing | 2025 |
| Jevcon Limited | Transport & logistics | 2013 |
| Jevids Care CIC | Health & social care | 2025 |
| Jevids Services Ltd | Health & social care | 2019 |
| Jewel Homes Limited | Real estate | 2018 |
| Jewellore Limited | Administrative & support | 2015 |
| Jewitt Production Services Limited | Administrative & support | 2011 |
| Jezzard Engineering Zervices Ltd | Administrative & support | 2007 |
| JF CAD Services 2 Ltd | Administrative & support | 2023 |
| JF Corporate Advisory Limited | Professional & scientific | 2014 |
| JF Housing Ltd | Real estate | 2024 |
| JF IT Consultancy Ltd | Administrative & support | 2025 |
| Jfbr Group Limited | Financial services | 2018 |
| JFL Consulting Ltd | Information & communication | 2019 |
| JFM Plastics and Property Maintenance Limited | Construction | 2014 |
| JFM Rooflines Limited | Construction | 2023 |
| JFN Management Limited | Real estate | 2018 |
| JFP Services Ltd | Professional & scientific | 2023 |
| JFS Training Ltd | Professional & scientific | 2023 |
| Jfsm Limited | Professional & scientific | 2019 |
| JG Mitchell Ltd | Professional & scientific | 2026 |
| JG Protech Ltd | Professional & scientific | 2023 |
| JG Structures Ltd | Professional & scientific | 2019 |
| JGA Consultancy Limited | Professional & scientific | 2021 |
| JGB Consultancy Ltd | Professional & scientific | 2024 |
| JGB Consulting Ltd | Professional & scientific | 2023 |
| JGB Systems Limited | Information & communication | 2016 |
| Jgbn Property Ltd | Real estate | 2023 |
| JGR Automotive Repairs Ltd | Wholesale & retail | 2025 |
| JGR UK Distributions Limited | Wholesale & retail | 2003 |
| JGS East Anglia Limited | Administrative & support | 2015 |
| JH Communications Limited | Administrative & support | 2023 |
| JH Safety Consulting Ltd | Professional & scientific | 2013 |
| JHA Electrical Construction Ltd | Professional & scientific | 2026 |
| JHA Property Development Ltd | Real estate | 2020 |
| JHA Property Estates Ltd | Real estate | 2025 |
| JHB Consulting Services Limited | Professional & scientific | 2016 |
| JHC Construction Consultants Ltd | Administrative & support | 2026 |
| Jhcsl Bars Limited | Hospitality | 2022 |
| Jhcsl Services Limited | Hospitality | 2020 |
| Jhrl Design Ltd | Administrative & support | 2021 |
| JHW Safety Limited | Professional & scientific | 2009 |
| Jiaesten Ltd | Wholesale & retail | 2023 |
| Jiangshan Property Limited | Real estate | 2024 |
| JIE AYO Limited | Information & communication | 2026 |
| JIG Electrical Ltd | Construction | 2019 |
| Jigsaw Property Group Ltd | Real estate | 2019 |
| Jigsaw Technology Consulting Services Ltd | Information & communication | 2023 |
| JIL Consulting Ltd | Extraterritorial | 2011 |
| Jila Consulting Limited | Information & communication | 2024 |
| Jila Properties Ltd | Real estate | 2024 |
| JIM Yates & Sons Ltd | Construction | 2003 |
| Jinal Solutions Limited | Other services | 2013 |
| Jipjip Consultancy Ltd | Professional & scientific | 2024 |
| Jireh PVT Ltd | Health & social care | 2022 |
| Jish Consulting Limited | Professional & scientific | 2024 |
| JJ Best Food Limited | Wholesale & retail | 2015 |
| JJ Enterprise Limited | Administrative & support | 2009 |
| JJ Fleet Disposals Limited | Wholesale & retail | 2014 |
| JJ Floors Ltd | Construction | 2020 |
| JJ Mckenna Limited | Arts & recreation | 2014 |
| JJ Rickson Limited | Transport & logistics | 2025 |
| JJ Services Private Ltd | Wholesale & retail | 2026 |
| JJ Sound Limited | Administrative & support | 2024 |
| JJ Sports Wear Ltd. | Wholesale & retail | 2020 |
| JJ Weldfab Limited | Administrative & support | 2024 |
| JJ8 Elite Ltd | Professional & scientific | 2019 |
| JJA Consulting Limited | Real estate | 2009 |
| JJB Engtech Limited | Administrative & support | 2014 |
| JJD Technology Holdings Limited | Information & communication | 2022 |
| Jjee Limited | Professional & scientific | 2021 |
| Jjlr Limited | Construction | 2011 |
| JJN Management Services Limited | Administrative & support | 2025 |
| Jjom Limited | Extraterritorial | 2012 |