| Jancill Limited | Health & social care | 2004 |
| Janris Limited | Health & social care | 2011 |
| Janvir Ltd | Real estate | 2022 |
| Jaques Clearance Ltd | Professional & scientific | 2013 |
| JAR Marketing Ltd | Information & communication | 2014 |
| Jarrett Plumbing Services Ltd | Construction | 2022 |
| Jarvis Fire & Security Limited | Public administration | 2021 |
| JAS Civil Engineering Limited | Construction | 2020 |
| Jasdent Property Ltd | Real estate | 2024 |
| Jasmine Garden 166 Ltd | Hospitality | 2024 |
| Jasmine Waterside Phase 1 Management Limited | Real estate | 2015 |
| Jasper and Chrysolyte Company Limited | Health & social care | 2015 |
| Jaspers Cafe Cornerstone Ltd | Hospitality | 2024 |
| Jassal Group Ltd | Real estate | 2019 |
| JAW Electrics Ltd | Construction | 2017 |
| Jawson ALL in One Store Ltd | Wholesale & retail | 2018 |
| Jayashree Management PVT Ltd | Wholesale & retail | 2022 |
| Jayletay Ltd | Wholesale & retail | 2017 |
| Jayna Business Solutions Limited | Professional & scientific | 2020 |
| Jayogun Property Investment Ltd | Real estate | 2025 |
| Jayson Stickings Limited | Professional & scientific | 2005 |
| JB Abseiling Ltd | Professional & scientific | 2025 |
| JB Freiberga Ltd | Health & social care | 2023 |
| JB Lifting and Haulage Limited | Transport & logistics | 2026 |
| JB Sims Garden Care Ltd | Administrative & support | 2025 |
| JB Sports Therapy Limited | Other services | 2013 |
| JB Tiling Kent Ltd | Construction | 2025 |
| JBS Inc Limited | Health & social care | 2023 |
| JC Steelworks Limited | Manufacturing | 2026 |
| JCC Services (Kent) Ltd | Construction | 2019 |
| JCO Living Limited | Real estate | 2024 |
| JCP Hydraulics Limited | Manufacturing | 1997 |
| JD Autos Kent Ltd | Wholesale & retail | 2026 |
| JD Clearance Ltd | Water & waste | 2025 |
| JD Coach Holidays Ltd | Administrative & support | 2025 |
| JD Property Facilities Limited | Households | 2025 |
| Jdarko Limited | Health & social care | 2023 |
| JDC Decoration & Renovations Ltd | Construction | 2010 |
| JDL Civil Engineering Limited | Construction | 2015 |
| Jdpw Morris Limited | Wholesale & retail | 2025 |
| JE Lift Group Ltd | Construction | 2021 |
| JEC Access Solutions Ltd | Construction | 2025 |
| Jefferies Structures Ltd | Construction | 2021 |
| Jeffgyms Ltd | Arts & recreation | 2025 |
| Jekebbi Limited | Administrative & support | 2014 |
| Jepan Ltd | Health & social care | 2021 |
| Jerin & Co Ltd | Health & social care | 2014 |
| Jerk Cafe Ltd | Hospitality | 2017 |
| Jerry Holdings Ltd | Other services | 2024 |
| JES Electrical Kent Limited | Construction | 2023 |
| Jess Gale Ltd | Professional & scientific | 2020 |
| JET Bean Rochester Limited | Hospitality | 2026 |
| JET Catt Properties Limited | Real estate | 2020 |
| Jethill Limited | Real estate | 2022 |
| Jetmax Ltd | Other services | 2021 |
| Jeujed Ltd | Other services | 2023 |
| JFL Properties Kent Limited | Other services | 2023 |
| JFT Investments Limited | Real estate | 2024 |
| JG Electrical (UK) Limited | Construction | 2008 |
| JG Houlage Ltd | Transport & logistics | 2019 |
| JH9 Limited | Real estate | 2020 |
| Jhfc Farming Ltd | Agriculture & fishing | 2012 |
| Jide's Delivery Services Limited | Transport & logistics | 2018 |
| Jigsaw Play Therapy Ltd | Health & social care | 2014 |
| Jimchiz UK Ltd | Construction | 2019 |
| Jireh Travels & Tours Ltd | Administrative & support | 2017 |
| JJ Coaching Ltd | Arts & recreation | 2023 |
| JJG Planning Solutions Ltd | Professional & scientific | 2017 |
| JJM Neilson Properties Limited | Real estate | 2025 |
| JJS GAS and Heating Limited | Construction | 2020 |
| JK Consultants (Kent) Limited | Information & communication | 2006 |
| JK Cooling Solutions Ltd | Construction | 2025 |
| JK Curtains & Blinds Ltd | Construction | 2013 |
| JK Global Ventures Limited | Administrative & support | 2025 |
| JK Performance Ltd | Education | 2025 |
| JKB Commercial Management Ltd | Construction | 2021 |
| JKB Services Ltd | Manufacturing | 2020 |
| JKR International Group Ltd | Wholesale & retail | 2026 |
| JKW Estates Limited | Real estate | 2023 |
| JL Land and Homes Limited | Real estate | 2024 |
| JL M and E Ltd | Construction | 2026 |
| JL Tax Services Ltd | Professional & scientific | 2025 |
| JLB Electricall Ltd | Construction | 2022 |
| JLB Rigging Ltd | Construction | 2021 |
| JLC Rigging Ltd | Construction | 2026 |
| JLG Heating & Plumbing Ltd | Construction | 2021 |
| JLG Property Services Ltd | Real estate | 2024 |
| JLM Artificial Lawns and Landscaping Limited | Administrative & support | 2021 |
| JM Tech Consulting Ltd | Information & communication | 2025 |
| JMB Safety Services Ltd | Professional & scientific | 2025 |
| JME LEE Services Ltd | Information & communication | 2026 |
| JMJ Landscapes Ltd | Administrative & support | 2024 |
| JMR Media International Ltd | Information & communication | 2023 |
| JMS Stone and Brickwork Limited | Construction | 2018 |
| JMT Installs Ltd | Wholesale & retail | 2019 |
| JNB Decorating Ltd | Construction | 2025 |
| JNB Painting and Building Services Ltd | Construction | 2025 |
| JNE Plumbing & Builders Ltd | Construction | 2021 |
| JNG Vulcanising Ltd | Construction | 2022 |
| JNL GAS Engineers Ltd | Construction | 2026 |