| JFO Trading 26 Ltd | Wholesale & retail | 2026 |
| JFO Trading Ltd | Wholesale & retail | 2022 |
| JGG Property Ltd | Real estate | 2026 |
| JGJ Housing Ltd | Real estate | 2017 |
| JGM Business Advisory Services Limited | Professional & scientific | 2012 |
| Jgul Investment Ltd | Real estate | 2021 |
| JH Electrical 24 7 Ltd | Construction | 2018 |
| JH Therapy Limited | Health & social care | 2023 |
| JHB Contract Services Limited | Professional & scientific | 2007 |
| JHC Supplies Ltd | Wholesale & retail | 2025 |
| JHK Trends Limited | Wholesale & retail | 2018 |
| JHM Future Solutions Ltd | Financial services | 2024 |
| JI Properties and Investments Ltd | Real estate | 2024 |
| JI4 Limited | Construction | 2025 |
| JIF Transport Limited | Real estate | 1974 |
| Jigsaw (New) Limited | Wholesale & retail | 2019 |
| Jihangir Limited | Wholesale & retail | 2017 |
| Jill's Pizza Ltd | Hospitality | 2021 |
| JJ & D Homes Ltd | Real estate | 2022 |
| JJ Cargo Ltd. | Transport & logistics | 2020 |
| JJ Enfield Cafe Ltd | Hospitality | 2020 |
| JJ Fast Foods Limited | Extraterritorial | 2009 |
| JJ Food Holding Co Ltd | Financial services | 2019 |
| JJ Food Service Distribution Limited | Professional & scientific | 2016 |
| JJ Food Service Limited | Wholesale & retail | 1988 |
| JJ Plumbing and Heating Services Ltd | Construction | 2018 |
| Jj&G Property Services Ltd | Real estate | 2025 |
| JJC Cleaning Services Ltd | Households | 2015 |
| Jjcd Services Ltd | Professional & scientific | 2026 |
| JJE Portfolio Property Ltd | Real estate | 2022 |
| Jjfs Investments Limited | Financial services | 2022 |
| JJL Trees Limited | Agriculture & fishing | 2016 |
| JJZ Food Ltd | Hospitality | 2023 |
| Jj’S Wastage and Recycling Ltd | Transport & logistics | 2025 |
| JK Fine Art Studio Ltd | Arts & recreation | 2025 |
| JK1 Medical Ltd | Health & social care | 2025 |
| JK1 Property Ltd | Real estate | 2024 |
| Jkfe Ltd | Real estate | 2021 |
| JKR Invest Limited | Real estate | 2025 |
| JKS Consult Limited | Real estate | 2012 |
| JL Investments Holding Company Limited | Financial services | 2022 |
| JL Whitley Construction Ltd | Construction | 2023 |
| Jl&L Ltd | Real estate | 2020 |
| Jl's Nails Limited | Other services | 2025 |
| JLA Media Ltd | Professional & scientific | 2008 |
| JLC Building Ltd | Construction | 2013 |
| JM Kensington Limited | Real estate | 2013 |
| JM Locks Ltd | Other services | 2024 |
| Jm.Delivery Limited | Transport & logistics | 2020 |
| JMD FX Ltd | Financial services | 2025 |
| JMP Rigden Estates Limited | Professional & scientific | 2022 |
| JMP Rigden Properties Limited | Real estate | 2022 |
| JMQ Properties Ltd | Real estate | 2024 |
| JMS Corporation Limited | Transport & logistics | 2018 |
| JN Care Finance Limited | Professional & scientific | 2016 |
| JN Nail & Spa Limited | Other services | 2023 |
| JNA Estates Group Limited | Real estate | 2026 |
| JNC Professional Services Limited | Professional & scientific | 2026 |
| JND Business Services Ltd | Information & communication | 2010 |
| JND Care Solutions Ltd | Health & social care | 2023 |
| Jnew Ltd | Financial services | 2026 |
| JNH Build Ltd | Construction | 2026 |
| JNR Auto Service Ltd | Wholesale & retail | 2025 |
| JNR Wholesale Limited | Wholesale & retail | 2025 |
| JOB Electrical Consultancy Limited | Manufacturing | 2014 |
| Joba Group Ltd | Wholesale & retail | 2020 |
| Jobson IT Services Limited | Other services | 2019 |
| Jobson IT Solutions Ltd | Information & communication | 2019 |
| Jocks Socks Ltd | Wholesale & retail | 2024 |
| JOE Foster Catering Ltd | Hospitality | 2024 |
| Joella Global Concept Limited | Information & communication | 2018 |
| Jofiel LP | | 2014 |
| John Hanley Limited | Construction | 1991 |
| John Inez Properties Limited | Real estate | 2023 |
| John Jordon Ltd | Wholesale & retail | 2022 |
| John Perrin & Sons Limited | Other services | 2013 |
| John Tann Ltd | Professional & scientific | 2019 |
| Johnec Cleaning Services Limited | Administrative & support | 2020 |
| Johnston's Home Care Ltd. | Health & social care | 2019 |
| Joint Buss Limited | Construction | 2016 |
| Joint Ltd | Wholesale & retail | 2025 |
| Jojo Services Ltd | Transport & logistics | 2023 |
| Jojozaza Ltd | Health & social care | 2022 |
| Jokemas Limited | Health & social care | 2020 |
| Jokkas Pizza Limited | Hospitality | 2026 |
| Jolie & Kylie Limited | Other services | 2021 |
| Jolly Beans Enfield Ltd | Hospitality | 2023 |
| Jolly C Limited | Real estate | 2022 |
| Jolly Kids Day Nursery Ltd | Education | 2011 |
| Jolo Leisure Limited | Health & social care | 2012 |
| Jolsen Limited | Professional & scientific | 2012 |
| Jomac (UK) Limited | Construction | 2003 |
| Jonas Mukamba Mukenge Ltd | Manufacturing | 2014 |
| Jonathan Ayliffe Limited | Construction | 2016 |
| Jonathan Court Management (Enfield) Limited | Households | 1978 |
| Jonny Silistra Ltd | Construction | 2020 |
| Joom Solutions Ltd | Wholesale & retail | 2025 |
| Jopf RF Ltd | Wholesale & retail | 2020 |
| Jordan Wheel Craft Limited | Wholesale & retail | 2007 |
| Jordancharlestalent Ltd | Administrative & support | 2017 |