| Jigsaw S.E. Limited | Construction | 2022 |
| JIM Gorrie Mentoring Limited | Professional & scientific | 2020 |
| Jim's Recovery Ltd Limited | Wholesale & retail | 2021 |
| Jimmyjames Ltd | Arts & recreation | 2012 |
| Jiph Limited | Real estate | 2021 |
| Jisha Real Estate Ltd | Real estate | 2022 |
| Jisprita Ltd | Wholesale & retail | 2022 |
| Jiu-Jitsu Life Ltd | Arts & recreation | 2020 |
| Jivani Corporation Ltd | Health & social care | 2024 |
| JJ Accountancy Solutions Limited | Real estate | 2018 |
| JJ Commercial Vehicle Specialist Limited | Wholesale & retail | 2015 |
| JJ Creative Construction Ltd | Construction | 2021 |
| JJ Creative Limited | Administrative & support | 2011 |
| JJ Premier Properties Limited | Real estate | 2026 |
| JJ Smith Ltd | Health & social care | 2020 |
| Jjims Ltd | Real estate | 2020 |
| JJL Services (Ashford) Ltd | Administrative & support | 2016 |
| JJM Plant Services Ltd | Administrative & support | 2017 |
| JJP Asset Holdings Ltd | Financial services | 2021 |
| JK 2024 Ltd | Transport & logistics | 2024 |
| JK Asap Limited | Wholesale & retail | 2016 |
| JK Hot Foods Limited | Hospitality | 2025 |
| JK Retailers Ltd | Wholesale & retail | 2023 |
| JKA Consultancy & Bookkeeping Limited | Professional & scientific | 2020 |
| JKB Steelworks Ltd | Professional & scientific | 2025 |
| JKO Media Limited | Administrative & support | 2018 |
| Jkor Limited | Financial services | 2012 |
| JKP Cafe Limited | Wholesale & retail | 2021 |
| JKP Hair Care Limited | Other services | 2023 |
| JKP Hairspa Limited | Other services | 2026 |
| JKP Therapy Rooms Limited | Other services | 2019 |
| JKR Recycling Services Limited | Water & waste | 2013 |
| Jksd Properties Limited | Real estate | 2021 |
| JKT Locums Limited | Wholesale & retail | 2023 |
| JL Consulting (Kent) Limited | Information & communication | 2013 |
| Jlab Consulting Ltd | Professional & scientific | 2020 |
| JLH Solutions Ltd | Information & communication | 2025 |
| Jlmp Developer Services Ltd | Professional & scientific | 2025 |
| Jlmr Limited | Real estate | 2000 |
| Jlmt Limited | Financial services | 2024 |
| JLN Electrical Limited | Construction | 2015 |
| JLP and Sons Contractors Ltd | Water & waste | 2019 |
| Jlr.L.R Engineering Solutions Limited | Construction | 2019 |
| JLS Blinds Ltd | Other services | 2014 |
| JLT Marketing Ltd | Professional & scientific | 2013 |
| JM Capital Holding Ltd | Financial services | 2023 |
| JM Cutts Consultants Ltd | Professional & scientific | 2012 |
| JM Farkas Holding Ltd | Financial services | 2024 |
| JM Farkas Ltd | Education | 2023 |
| JM Farkas Real Estate Ltd | Real estate | 2024 |
| JM Financial Planning Limited | Financial services | 2003 |
| JM Flanagan Ltd | Construction | 2019 |
| JM Milton Property Limited | Real estate | 2025 |
| JM Tower Bridge Limited | Real estate | 2021 |
| Jmat Railway Engineering Ltd | Construction | 2018 |
| JMB Builders Kent Ltd | Construction | 2023 |
| JMG Bathroom, Heating & Plumbing Supplies Limited | Wholesale & retail | 2005 |
| JMH Bricklaying Services Ltd | Construction | 2025 |
| JMK Electrics Southeast Ltd | Manufacturing | 2014 |
| Jmkp Ltd | Construction | 2020 |
| Jmmw Limited | Agriculture & fishing | 2020 |
| JMW Electrical IOW Limited | Construction | 2017 |
| JNB Property Services Limited | Administrative & support | 2010 |
| JNR Accounting Limited | Professional & scientific | 2015 |
| JO & Cole Dental Management Solutions Ltd | Professional & scientific | 2026 |
| Joanna Milligan Consulting Limited | Professional & scientific | 2025 |
| Jobe Workshop Equipment Ltd | Wholesale & retail | 2026 |
| Jobmatcha Ltd | Administrative & support | 2021 |
| Jobs & Talent Limited | Professional & scientific | 1998 |
| Jockey Heating Limited | Construction | 2026 |
| JOE Carter Utility Surveying Limited | Professional & scientific | 2021 |
| Joel Michaels Associates Limited | Professional & scientific | 2005 |
| Joels Cafe Limited | Hospitality | 2024 |
| Joeshella Limited | Health & social care | 2021 |
| JOF Marvel Ltd | Information & communication | 2019 |
| John & Barbara Investments Limited | Real estate | 2004 |
| John Bowley and Sherwood Almshouses | Health & social care | 2011 |
| John Burns Ltd | Construction | 2016 |
| John Butler Associates Limited | Information & communication | 1996 |
| John Cossey Roofing & Maintenance Contractors Ltd | Construction | 2003 |
| John Hope Consulting Limited | Professional & scientific | 2014 |
| John Page Trailers Limited | Wholesale & retail | 2004 |
| John Paine (Kent) Potatoes Limited | Agriculture & fishing | 1939 |
| John Rogers Design Ltd | Hospitality | 2005 |
| John Russell & SON (Canterbury) Limited | Construction | 2019 |
| John Underwood Consulting (Kent) Limited | Mining & quarrying | 1997 |
| John-Stanley Champneys Limited | Extraterritorial | 2023 |
| Johns Carpets Limited | Wholesale & retail | 2024 |
| Johnson Flooring Services Ltd | Construction | 2026 |
| Join the Dots Psychology Limited | Health & social care | 2025 |
| Joinery Space Ltd | Manufacturing | 2011 |
| Jollies House Limited | Health & social care | 2012 |
| Jolo Limited | Health & social care | 2014 |
| Jolt Accounting Ltd | Professional & scientific | 2019 |
| Joltech Limited | Wholesale & retail | 2002 |
| Jonathan Allen Limited | Professional & scientific | 2003 |
| Jonathan Hayden Literary Agents Ltd | Professional & scientific | 2018 |
| Jonax Ltd | Wholesale & retail | 2025 |
| Jones Hairdressing Limited | Other services | 2021 |
| Jones Turton Limited | Administrative & support | 2011 |