| Jani Brand Corporation Ltd | Arts & recreation | 2026 |
| Jannetta Consultancy Limited | Health & social care | 2024 |
| Jarrett Scaffolding Limited | Construction | 2011 |
| Jarrow Specsavers Limited | Wholesale & retail | 2023 |
| Jarvis Business Solutions Limited | Information & communication | 2025 |
| Jasa Holdings Ltd | Financial services | 2022 |
| Jasiri Global Limited | Wholesale & retail | 2025 |
| Jasmine Cheema Psychotherapy Ltd | Health & social care | 2022 |
| Jasmine Plowright Consulting Limited | Professional & scientific | 2016 |
| Jasmine Saunders Hair Limited | Other services | 2025 |
| JAT Garrison Holdings Limited | Real estate | 2018 |
| Jaws Scaffolding Ltd | Construction | 2024 |
| Jayne Jempson Limited | Health & social care | 2024 |
| Jayprop Prime Limited | Information & communication | 2025 |
| Jayprop Software Limited | Other services | 2020 |
| JB Accounting Hub Ltd | Information & communication | 2023 |
| JB Carpentry Contractors (Southern) Ltd | Construction | 2022 |
| JB Carpentry Contractors Ltd | Construction | 2017 |
| JB Cleaning Contractors Ltd | Administrative & support | 2023 |
| JB Electric Contractors Ltd | Construction | 2014 |
| JB Homes (Southern) Ltd | Construction | 2021 |
| JB South Heating Ltd | Construction | 2019 |
| Jbae Property Solutions Ltd | Construction | 2025 |
| JBC Financial Consulting Limited | Financial services | 2005 |
| Jbhh Property Holdings Limited | Construction | 2026 |
| JC Business Intelligence Limited | Information & communication | 2016 |
| JC Hydrographic Ltd | Other services | 2026 |
| JC Recruitment Hire Limited | Administrative & support | 2025 |
| JC Signalling Solutions Ltd | Professional & scientific | 2018 |
| JC001 Limited | Extraterritorial | 2011 |
| JC002 Limited | Extraterritorial | 2011 |
| Jchm Services Ltd | Construction | 2017 |
| Jcmw Keswick Ltd | Hospitality | 2025 |
| Jcpsa Ltd | Extraterritorial | 2025 |
| JCR Commercial Projects Ltd | Construction | 2026 |
| JCT Automation Ltd | Professional & scientific | 2022 |
| JD Financial Solutions Ltd | Financial services | 2021 |
| JD Grant Plumbing & Heating Limited | Construction | 2020 |
| JD Operations Ltd | Information & communication | 2018 |
| JDB Mechanical Ltd | Construction | 2020 |
| Jdcl Coaching Limited | Arts & recreation | 2009 |
| JDE Contracting Ltd | Construction | 2024 |
| JDF Nexus Ltd | Information & communication | 2023 |
| JDM Industrial Limited | Wholesale & retail | 2017 |
| JDP Football Limited | Other services | 2026 |
| JDS Drylining Ltd | Construction | 2026 |
| JE Property Assets Ltd | Real estate | 2026 |
| JED Rogers Consulting Ltd | Administrative & support | 2022 |
| Jedtech Consulting Limited | Information & communication | 2010 |
| Jeff Bodle Plumbing Services Ltd | Construction | 2012 |
| Jefferson Holdings Limited | Other services | 2016 |
| JEG Commercial Services Limited | Construction | 2025 |
| Jenkins Farm Agri Limited | Agriculture & fishing | 2025 |
| Jentle Therapies Ltd | Health & social care | 2025 |
| Jersey Telecom (UK) Limited | Information & communication | 1999 |
| Jessica Watt Ltd | Administrative & support | 2022 |
| JET Cards Limited | Wholesale & retail | 2021 |
| JET Promotions Limited | Arts & recreation | 2004 |
| Jewellery Boulevard Ltd | Wholesale & retail | 2023 |
| Jewer Southern Limited | Real estate | 2016 |
| Jezard Contracting Ltd | Administrative & support | 2024 |
| JF Consulting 247 Ltd | Professional & scientific | 2023 |
| JFP Langdon Holdings Limited | Financial services | 2026 |
| JG Lifestyle Ltd | Arts & recreation | 2022 |
| JGC Property Services Ltd | Construction | 2013 |
| JGM Scaffolding Ltd | Construction | 2011 |
| JH City Property Construction Limited | Construction | 2026 |
| JH Flooring Limited | Construction | 2026 |
| JH Technical Solutions Ltd | Information & communication | 2023 |
| JH1 Limited | Information & communication | 2008 |
| Jhh-Heating Ltd | Construction | 2025 |
| JHX Modern Ltd | Wholesale & retail | 2020 |
| Jigsaw Plumbing & GAS Limited | Construction | 2018 |
| Jigsaw Property Management Group Limited | Real estate | 2019 |
| JJ Harris Holdings Ltd | Financial services | 2025 |
| JJ Inventories Limited | Administrative & support | 2012 |
| JJA Engineering Solutions Limited | Construction | 2024 |
| JJA Safety Consulting Limited | Professional & scientific | 2023 |
| Jjcg Services Limited | Transport & logistics | 2023 |
| JJN Groundworks Limited | Administrative & support | 2026 |
| JJR (Town & Country) Limited | Financial services | 2023 |
| JK Homes Southern Ltd | Real estate | 2025 |
| JK Residential Holdings Ltd | Real estate | 2026 |
| JK System Solutions Ltd | Administrative & support | 2015 |
| Jk&D Limited | Administrative & support | 2019 |
| Jkja Ltd | Real estate | 2026 |
| JL Fire Protection Limited | Construction | 2025 |
| JL Ventures (PVT) Ltd | Financial services | 2015 |
| JL Ventures Property Services Ltd | Real estate | 2020 |
| JLB Recruitment Ltd | Administrative & support | 2020 |
| JLG Holdings Limited | Administrative & support | 2021 |
| JLH Residential Limited | Real estate | 2026 |
| JM Homecare Ltd | Health & social care | 2015 |
| JMA Rose Property Group Ltd | Real estate | 2023 |
| JMA Rose Property Investment Ltd | Real estate | 2025 |
| Jmbdd Design Services Limited | Information & communication | 2005 |
| JMC Car Sales Ltd | Wholesale & retail | 2024 |
| JML IT Consultants Limited | Information & communication | 2011 |
| JML PT Limited | Other services | 2022 |
| Jmurphyplumbing Ltd | Construction | 2025 |