| Jeorin Ltd | Wholesale & retail | 2025 |
| Jeremiah International Limited | Education | 2023 |
| Jerky Chipz Ltd | Hospitality | 2021 |
| Jesco Property Services Ltd | Real estate | 2022 |
| Jesmin Prime Medical Ltd | Health & social care | 2026 |
| Jesse Investments Ltd | Real estate | 2020 |
| Jessica FOX Ltd | Wholesale & retail | 2021 |
| JET Fire Extinguishers Limited | Extraterritorial | 2000 |
| JET Mobile Living Ltd | Real estate | 2025 |
| Jetker Ltd | Administrative & support | 2021 |
| Jetprodriveway Limited | Administrative & support | 2025 |
| Jevony Limited | Wholesale & retail | 2024 |
| Jewellers Hand Ltd | Wholesale & retail | 2015 |
| Jewelz Cookery Limited | Extraterritorial | 2020 |
| Jex.Ed Ltd | Hospitality | 2021 |
| Jeyjan Ltd | Construction | 2021 |
| JF Assets Limited | Professional & scientific | 2018 |
| JF Whiting & Co Ltd | Professional & scientific | 2026 |
| JFA Flooring Limited | Construction | 2018 |
| JFB London Ltd | Transport & logistics | 2020 |
| JFJ Digi Spark Ltd | Other services | 2024 |
| Jfol Construction Limited | Construction | 2024 |
| JFP Vantage Ltd | Construction | 2017 |
| Jfpsnow Limited | Other services | 2025 |
| JG & MS Properties Limited | Construction | 2019 |
| JG Living Ltd | Real estate | 2025 |
| JGN Mortgages Ltd. | Professional & scientific | 2017 |
| Jgorge Cleaning Services Ltd | Construction | 2024 |
| JH Smart Trading Ltd | Energy | 2021 |
| JHA Compliance Solutions Ltd | Professional & scientific | 2023 |
| Jhahan Property Ltd | Real estate | 2024 |
| Jharris Traders Limited | Wholesale & retail | 2019 |
| JHF Roofing Ltd | Construction | 2026 |
| JHF Services Limited | Extraterritorial | 2016 |
| JHM Consultancy Group Limited | Professional & scientific | 2016 |
| Jhony Evergreen Ltd | Construction | 2026 |
| Jhonybbq Grill Ltd | Hospitality | 2024 |
| JHS Building Services (UK) Ltd | Construction | 2010 |
| Jhujh Limited | Wholesale & retail | 2024 |
| Jibon Healthcare Limited | Health & social care | 2026 |
| Jidiva Ltd | Manufacturing | 2025 |
| JIF Building Services Ltd | Other services | 2021 |
| Jigg Estates Limited | Real estate | 2020 |
| Jigsaw Therapy Ltd | Health & social care | 2024 |
| Jigso LLP | | 2006 |
| Jimmys Barber Ltd | Other services | 2020 |
| Jimoh & Sons Property Solutions Ltd | Households | 2026 |
| Jina Limited | Wholesale & retail | 2002 |
| Jingle Gorman Limited | Health & social care | 2015 |
| JJ Lawrence Electrical Limited | Construction | 2013 |
| JJ Savill Limited | Health & social care | 2016 |
| JJ Timber Merchant Ltd | Wholesale & retail | 2024 |
| JJ Tyres London Ltd | Wholesale & retail | 2024 |
| JJC Services Ltd | Education | 2024 |
| JJJ Tech Consultancy Limited | Information & communication | 2026 |
| JJW Contractors Ltd | Administrative & support | 2011 |
| JK Beauty Hub Ltd | Other services | 2019 |
| JK Facades Ltd | Construction | 2022 |
| JK Horizon Ltd | Real estate | 2026 |
| JK Partners Limited | Real estate | 2016 |
| JK1 Developments Ltd | Construction | 2021 |
| JK1 Properties Ltd | Real estate | 2026 |
| JKM Electrics Ltd | Manufacturing | 2020 |
| JLC Powerful Health Solutions Ltd | Wholesale & retail | 2023 |
| Jlcb Consulting Limited | Professional & scientific | 2023 |
| JLM Print & Design Limited | Manufacturing | 2015 |
| JM Gas&Heating Ltd. | Construction | 2015 |
| JM Lansbury Investments Limited | Real estate | 2025 |
| JM Short Term Accommodation Ltd | Hospitality | 2025 |
| JM Sydney Ltd | Transport & logistics | 2021 |
| Jmax Services Ltd | Manufacturing | 2021 |
| JMB Tours Limited | Administrative & support | 2026 |
| Jmcba Enterprises Ltd | Administrative & support | 2013 |
| Jmcc Trades Ltd | Construction | 2021 |
| Jmcsa Ltd | Health & social care | 2022 |
| JMD Consults & Partners Limited | Information & communication | 2018 |
| JMD Professionals Limited | Information & communication | 2018 |
| JMG Windows & Construction Ltd | Construction | 2024 |
| JMH Florists Limited | Wholesale & retail | 2008 |
| JMK Ventures Properties Ltd | Real estate | 2025 |
| Jmlt and KIN Limited | Wholesale & retail | 2025 |
| JMM Building Services Ltd | Construction | 2016 |
| JMM Electrical Co Ltd | Manufacturing | 2024 |
| JMN Utilities Limited | Energy | 2024 |
| JMO Mechanical Services Ltd | Professional & scientific | 2021 |
| Jmrc Holdings Ltd | Real estate | 2024 |
| Jmre Services Ltd | Health & social care | 2018 |
| JMS Build Ltd | Construction | 2019 |
| JMU Consultancy Ltd | Financial services | 2025 |
| JN & Sons Ltd | Construction | 2021 |
| JNA Construction Ltd | Construction | 2018 |
| JNJ Consultants Ltd | Professional & scientific | 2024 |
| Jnood Ltd | Health & social care | 2023 |
| JNR Properties (London) Limited | Real estate | 2020 |
| JNT Electrical Services Ltd | Construction | 2022 |
| Joa's Light Limited | Information & communication | 2009 |
| Joanna Drywall Ltd | Construction | 2026 |
| Joanomo Limited | Other services | 2024 |
| Joaque Incorporated Ltd | Manufacturing | 2025 |
| Joas Accessories Ltd | Manufacturing | 2025 |