| JBD Consulting Ltd | Professional & scientific | 2023 |
| JBD Homes Ltd | Real estate | 2023 |
| JBK Renovations Limited | Construction | 2026 |
| JBL Building Services Limited | Construction | 2021 |
| JBR Logistics London Limited | Transport & logistics | 2026 |
| JBR Services London Limited | Administrative & support | 2024 |
| JBR Trading London Limited | Wholesale & retail | 2024 |
| Jbrc Carpentry Limited | Construction | 2021 |
| JBW Invest Ltd | Real estate | 2018 |
| JC Goods Ltd | Wholesale & retail | 2025 |
| JC Property Consultancy Limited | Professional & scientific | 2018 |
| Jcdw Property Investors Ltd | Real estate | 2022 |
| Jceerecurit Ltd | Administrative & support | 2024 |
| JCG Hospitality Limited | Hospitality | 2019 |
| Jclaces Ltd | Wholesale & retail | 2025 |
| JCM Ceilings Limited | Construction | 2003 |
| JCT Consulting Ltd | Professional & scientific | 2024 |
| JD Beauty Salon and Spa Limited | Other services | 2023 |
| JD Burton Performance Ltd | Arts & recreation | 2016 |
| JD Harvin Consultancy Ltd | Professional & scientific | 2018 |
| JD Lighting Film & TV Ltd | Professional & scientific | 2014 |
| Jdad Solutions Ltd | Real estate | 2026 |
| JDB Project Managment Limited | Professional & scientific | 2010 |
| JDC Resources Ltd | Professional & scientific | 2023 |
| JDH Analytics Ltd | Information & communication | 2026 |
| JDM Distributors Limited | Wholesale & retail | 2013 |
| JDM Search Ltd | Administrative & support | 2024 |
| Jdsk Consultants Ltd | Professional & scientific | 2021 |
| JDT (Essex) Limited | Administrative & support | 2016 |
| JE Engineering & Construction Ltd. | Professional & scientific | 2018 |
| JE Projects Ltd | Information & communication | 2015 |
| Jean LUC Properties Limited | Construction | 2024 |
| Jean-Luc Developments Ltd | Construction | 2009 |
| Jean-Luc Estates Ltd | Financial services | 2023 |
| Jean-Luc Investments Ltd | Financial services | 2022 |
| Jean-Pierre Dupont Consulting Ltd | Administrative & support | 2018 |
| Jedi Services Ltd | Information & communication | 2025 |
| Jeer Estates Limited | Real estate | 2019 |
| Jeer Medicolegal Reporting Limited | Health & social care | 2012 |
| Jeer Orthopaedics Limited | Health & social care | 2012 |
| Jeer Property Investments Limited | Other services | 2014 |
| Jeeva Service Station Ltd | Wholesale & retail | 2018 |
| Jeff Akwaboah Limited | Information & communication | 2014 |
| Jeffrey Chang & Co Limited | Administrative & support | 2024 |
| Jehoyada Clockwork Partners Limited | Information & communication | 2025 |
| Jelim Investments Limited | Financial services | 2016 |
| Jelly Software Ltd | Information & communication | 2010 |
| JEM Security Limited | Manufacturing | 2003 |
| Jemily Cleaning Services Ltd | Administrative & support | 2022 |
| Jemmerley Limited | Professional & scientific | 2012 |
| Jemstar.Co.Uk Limited | Real estate | 2005 |
| Jenext Ltd | Wholesale & retail | 2026 |
| Jenga Design Limited | Information & communication | 2023 |
| Jenmi Tech Consultancy Ltd | Information & communication | 2025 |
| Jenny's Kitchen Limited | Extraterritorial | 2020 |
| Jepeca Limited | Education | 2004 |
| Jerasoft LLP | | 2007 |
| Jeremy Bloom Consulting Ltd | Professional & scientific | 2019 |
| Jeremy Vosser Consulting Limited | Professional & scientific | 2022 |
| JES Property Limited | Real estate | 2020 |
| Jesl Limited | Financial services | 2025 |
| JESSHOL2014 Ltd | Real estate | 2019 |
| Jessica Lemon Ltd | Professional & scientific | 2019 |
| Jestway Consultants Limited | Administrative & support | 2012 |
| Jesus Power Ltd | Health & social care | 2015 |
| JET Consulting Group Ltd | Information & communication | 2025 |
| JET SET Equine Limited | Arts & recreation | 2021 |
| Jetstream Analytics Limited | Administrative & support | 2014 |
| Jevit Consulting Ltd | Information & communication | 2010 |
| Jewel Cafe Ltd | Wholesale & retail | 2020 |
| Jewellery Mart Ltd | Wholesale & retail | 2025 |
| JEY Medical Limited | Health & social care | 2025 |
| JF & Associates Limited | Professional & scientific | 2015 |
| Jfab Property Group Ltd | Real estate | 2021 |
| Jfbunique Limited | Health & social care | 2021 |
| Jfdi International Limited | Information & communication | 2017 |
| JFJ Properties Ltd | Real estate | 2025 |
| Jfks Enterprise Ltd | Construction | 2023 |
| Jgec Ltd | Construction | 2026 |
| JGM Commercial Services Ltd | Professional & scientific | 2025 |
| JH Medical Limited | Health & social care | 2018 |
| JHH Contract Services Ltd | Information & communication | 2019 |
| JHJ Holdings Ltd | Financial services | 2019 |
| JHT Financial Consultancy Ltd | Professional & scientific | 2020 |
| Jiga Limited | Information & communication | 2011 |
| Jigaroo Ltd | Households | 2026 |
| Jigsaw Builders Ltd | Construction | 2019 |
| Jiim Jones Ltd | Administrative & support | 2022 |
| JIL Compliance Ltd | Professional & scientific | 2026 |
| Jilifu Ltd | Health & social care | 2019 |
| Jill Hunt Radiology Services Limited | Health & social care | 2014 |
| Jill's Night Nanny Services Limited | Health & social care | 2017 |
| Jimmlec Ltd | Construction | 2016 |
| Jimmy New Development Ltd | Construction | 2019 |
| Jimpy Limited | Administrative & support | 2022 |
| Jintsi Property Limited | Real estate | 2015 |
| Jinzen Limited | Hospitality | 2023 |
| Jivi IT Solutions Ltd | Information & communication | 2025 |
| JJ Caira Personal Training Limited | Health & social care | 2018 |
| JJ Connect Care Ltd | Administrative & support | 2011 |