| Jelka Projects Limited | Professional & scientific | 2026 |
| Jenkins & SON Fishmongers Ltd | Wholesale & retail | 2021 |
| Jenkins & SON Fishmongers Property Co Limited | Real estate | 2023 |
| Jennifer Nobbs Consulting Limited | Professional & scientific | 2026 |
| Jerlija Studio Ltd | Professional & scientific | 2025 |
| Jesco Network UK Ltd | Information & communication | 2007 |
| JF Investment & Property Limited | Real estate | 2021 |
| JGS Events Consultants Ltd | Hospitality | 2020 |
| Jimmyco Limited | Hospitality | 2016 |
| Jimmys Movers Ltd | Transport & logistics | 2026 |
| Jinja Biscuit Ltd | Real estate | 2018 |
| Jj&L Willis Limited | Financial services | 2026 |
| JJC Haulage Kent Limited | Transport & logistics | 2023 |
| JK Business Analytics Limited | Information & communication | 2025 |
| Jkjl Holdings Limited | Administrative & support | 2026 |
| Jkrab Limited | Wholesale & retail | 2015 |
| JLC Enterprise Group Ltd | Wholesale & retail | 2024 |
| Jlsdify Services Ltd | Other services | 2017 |
| JM Consulting Services Ltd | Professional & scientific | 2020 |
| Jmcp Advisory Limited | Professional & scientific | 2024 |
| Jmep Limited | Administrative & support | 2023 |
| Jmgb Solution Ltd | Construction | 2015 |
| JMK Properties Limited | Real estate | 1998 |
| JMS Tree Care Ltd | Agriculture & fishing | 2025 |
| JO & JAY Ltd | Professional & scientific | 2024 |
| JO Hubbard Coaching Limited | Professional & scientific | 2021 |
| JO Jo's Day Care Nursery - Canterbury Ltd | Education | 2024 |
| Joashdekku Ltd | Health & social care | 2014 |
| Jobforce Solutions Ltd | Information & communication | 2019 |
| Jocoalto Limited | Real estate | 2021 |
| Jogma Limited | Extraterritorial | 2019 |
| John ALI Taxi Ltd | Transport & logistics | 2024 |
| John Connor PA Limited | Information & communication | 2002 |
| John Datlen Limited | Professional & scientific | 2012 |
| John Downie Associates Ltd | Construction | 2023 |
| John Todd Media Ltd | Information & communication | 2018 |
| Johnny Fewings Media Consultancy Ltd | Administrative & support | 2010 |
| Johnson's Hillview Holdings Ltd | Real estate | 2026 |
| Joint Electrical Limited | Construction | 2006 |
| Joint Enterprise Ventures Ltd | Financial services | 2023 |
| Jomgan Ltd | Health & social care | 2024 |
| JON Cousins Ltd | Information & communication | 2015 |
| Jonah's Handling Limited | Agriculture & fishing | 2007 |
| Jonathan and Chiang Limited | Information & communication | 2020 |
| Jones Heating Ltd | Construction | 2026 |
| Jons GM Property Ltd | Real estate | 2016 |
| Jordan-Smith & Associates Ltd | Professional & scientific | 2010 |
| Joseph James Groundworks Limited | Construction | 2023 |
| Joshua Edward Reynolds Buggins Limited | Administrative & support | 2025 |
| Joss Bay Cafe Broadstairs Ltd | Hospitality | 2022 |
| Joss Bay Limited | Hospitality | 2018 |
| Jottle Ltd | Information & communication | 2026 |
| JOURNEY2YOU Limited | Health & social care | 2026 |
| Joyelse Limited | Construction | 2014 |
| JP Contracting Limited | Construction | 2005 |
| JP Luxury Kitchens Ltd | Manufacturing | 2018 |
| JP Rose Ltd | Wholesale & retail | 2024 |
| JPB Kentish Builders Ltd | Construction | 2023 |
| Jpbfd Limited | Professional & scientific | 2021 |
| JPM Hillside Holdings Limited | Construction | 2021 |
| JPR Maintenance & Construction Services Ltd | Construction | 2017 |
| Jremed Limited | Health & social care | 2023 |
| JS Autoworks Limited | Wholesale & retail | 2022 |
| JS Contracting Limited | Administrative & support | 2025 |
| JS Roof Care Services Ltd | Construction | 2025 |
| JS Virtual Solutions Ltd | Information & communication | 2025 |
| JSB Landscapes Limited | Construction | 2026 |
| JSN Automotive Limited | Wholesale & retail | 2018 |
| Jtodd Ventures Ltd | Wholesale & retail | 2021 |
| JTS Removals & Solutions Ltd | Water & waste | 2025 |
| Julian Jarman Practice Ltd | Health & social care | 2021 |
| Jumaya Consulting Ltd | Professional & scientific | 2019 |
| Jump & Dog Productions Limited | Information & communication | 2013 |
| Jumpstart Property Investments Ltd | Real estate | 2025 |
| Juniperus Digital Ltd | Information & communication | 2024 |
| Juno Connect Ltd | Information & communication | 2025 |
| Just a Uniform Ltd | Manufacturing | 2021 |
| Just Contract Management Limited | Professional & scientific | 2017 |
| Just Mart Ltd | Wholesale & retail | 2023 |
| Just Pump IT Ltd | Construction | 2019 |
| Justinteractive New Media Limited | Information & communication | 2002 |
| Justso Branded Limited | Other services | 2021 |
| JV Surveying (South East) Ltd | Professional & scientific | 2024 |
| JW ARB Training Ltd | Information & communication | 2022 |
| JXD Holdings Ltd | Financial services | 2021 |
| Jyldyz Grace Enterprise Limited | Administrative & support | 2023 |
| K & F Concrete Pumps Limited | Other services | 2022 |
| K & M Williams Limited | Administrative & support | 2018 |
| K & T Real Estate Limited | Real estate | 2021 |
| K Lambert Stokes Ltd | Wholesale & retail | 2025 |
| K&H Investments International Ltd | Wholesale & retail | 2025 |
| K&R Acquisitions Ltd | Real estate | 2025 |
| K&W Management Services Ltd | Real estate | 2024 |
| K&W Property Investments Ltd | Real estate | 2024 |
| K&W Yards Ltd | Financial services | 2025 |
| K. West Electrical Ltd | Construction | 2015 |
| K.C.S Home Ltd | Construction | 2017 |
| K249Y Electrical Limited | Construction | 2025 |
| K9 Spa Ltd | Wholesale & retail | 2026 |
| KA Estate Group Limited | Real estate | 2020 |