| JBG Consultants Ltd | Information & communication | 2026 |
| JCC (Kent) Limited | Wholesale & retail | 2009 |
| JCH Videography Limited | Extraterritorial | 2020 |
| JCM Advisors Ltd | Professional & scientific | 2016 |
| Jcmh Services Ltd | Financial services | 2022 |
| JD Bush Property Limited | Real estate | 2025 |
| JD Rays Ltd | Health & social care | 2025 |
| JDD Solutions Ltd | Construction | 2024 |
| JDH Homes Ltd | Construction | 2025 |
| JDI Stone Limited | Hospitality | 2018 |
| JDL Deliveries Ltd | Transport & logistics | 2011 |
| Jdml Talks Ltd | Education | 2024 |
| JE Ellis Ltd | Administrative & support | 2025 |
| Jean Haines Watercolour Inspiration Limited | Other services | 2019 |
| JEB Care Limited | Health & social care | 2026 |
| Jedbrig Services Limited | Professional & scientific | 2010 |
| Jedut Services Ltd | Transport & logistics | 2017 |
| JEJ (Kent) Limited | Construction | 2026 |
| Jelf Racing Team Limited | Arts & recreation | 2012 |
| Jels Cafe Limited | Hospitality | 2012 |
| Jemp Property Investments Limited | Real estate | 2013 |
| Jencar Training Ltd | Education | 2025 |
| Jenner and West Decorating Services Limited | Construction | 2022 |
| Jennie COX Chiropractic Ltd | Health & social care | 2024 |
| Jens PK Limited | Health & social care | 2019 |
| Jeremy Clark Limited | Health & social care | 2011 |
| Jeremy Dixon Limited | Wholesale & retail | 2003 |
| Jeremy Raymond Associates Ltd | Professional & scientific | 2010 |
| Jerome Moisan Ltd | Professional & scientific | 2018 |
| Jess Building Contractors Limited | Construction | 2010 |
| Jess Property Maintenance Limited | Administrative & support | 2010 |
| Jessica Marina Ltd | Wholesale & retail | 2021 |
| Jesters Parties Ltd | Arts & recreation | 2024 |
| JET Car Valet Ltd | Administrative & support | 2024 |
| JET Connect 24 Limited | Transport & logistics | 2017 |
| JET L Ltd | Transport & logistics | 2023 |
| Jevons Properties Ltd | Real estate | 2019 |
| Jevs Limited | Professional & scientific | 2020 |
| Jewelultra Holdings Limited | Professional & scientific | 1998 |
| Jewelultra Limited | Manufacturing | 1992 |
| JF Automotive Ltd | Wholesale & retail | 2011 |
| JF Commercial Services Ltd | Professional & scientific | 2022 |
| JF Electricians Ltd | Construction | 2025 |
| JG Acoustics Ltd | Professional & scientific | 2014 |
| JG Advisory Services Limited | Professional & scientific | 2023 |
| JG Healthcare Solutions Limited | Health & social care | 2023 |
| JG Property Partnership Limited | Real estate | 2025 |
| JGB Events LLP | | 2022 |
| Jgilham Investments Limited | Real estate | 2014 |
| JGR Carpentry and Building Ltd | Construction | 2025 |
| JH Infracore Limited | Professional & scientific | 2025 |
| JH Motor Mechanic Ltd | Wholesale & retail | 2025 |
| JHB Casa Investments Ltd | Construction | 2023 |
| JHB Roofing Solutions Ltd | Construction | 2023 |
| JHH Properties Ltd | Real estate | 2019 |
| JHH Telecoms Ltd | Administrative & support | 2020 |
| JHM Capital LLP | | 2020 |
| Jhswealth Consultancy Ltd | Administrative & support | 2021 |
| Jigsawtel Ltd | Information & communication | 2020 |
| Jilt Investments Ltd | Real estate | 2015 |
| JIM Harrow Limited | Professional & scientific | 1999 |
| Jimpa Limited | Professional & scientific | 2014 |
| Jireh Health Ltd | Health & social care | 2014 |
| Jireh Support Services Ltd | Professional & scientific | 2022 |
| Jitp Ltd | Information & communication | 2012 |
| JJ Ellis Limited | Health & social care | 2017 |
| JJ Project Management Limited | Construction | 2025 |
| JJA Solutions Ltd | Administrative & support | 2011 |
| Jjaf Group Ltd | Transport & logistics | 2025 |
| JJD Construction Ltd | Construction | 2005 |
| JJL Haulage Ltd | Transport & logistics | 2025 |
| JJS Electrical Services Ltd | Construction | 2021 |
| JJT Property Services Ltd | Real estate | 2022 |
| Jjusttgrp Ltd | Administrative & support | 2014 |
| JK Construction Fitter Ltd | Construction | 2021 |
| JK Fencing & Construction Ltd | Administrative & support | 2017 |
| JK Homes Kent Limited | Construction | 2016 |
| JK Investments (South East) Limited | Construction | 2026 |
| JK Property (South East) Limited | Construction | 2026 |
| JK Pubs and Bars Ltd | Hospitality | 2018 |
| JKE Technology and Innovations Ltd | Information & communication | 2024 |
| JL Golf Limited | Wholesale & retail | 2009 |
| JL Roofing and Leadwork Limited | Construction | 2026 |
| JLA Surveying & Property Services Ltd | Professional & scientific | 2024 |
| JLC Trading Ltd | Wholesale & retail | 2023 |
| JLF Homes Limited | Real estate | 2019 |
| JLJ Chemicals Ltd | Wholesale & retail | 2018 |
| JLK Scaffolding Ltd | Construction | 2018 |
| JLW Tax Consultancy Ltd | Professional & scientific | 2025 |
| JLW Training Ltd | Professional & scientific | 2019 |
| JM Bidco Limited | Financial services | 2021 |
| JM Civils Ltd | Construction | 2015 |
| JM Lynch Ecology Ltd | Professional & scientific | 2024 |
| JM Pharma Consulting Ltd | Administrative & support | 2013 |
| JM. P Transport Ltd | Transport & logistics | 2017 |
| JMA Strip OUT Limited | Construction | 2025 |
| JMB Haulage Limited | Construction | 2025 |
| Jmbs Engineering Ltd | Professional & scientific | 2017 |
| JNN Group Ltd | Education | 2025 |
| JNR Consultancy Ltd | Construction | 2018 |