| Joyang Real Estate Ventures Ltd | Real estate | 2024 |
| Joyce Pharmac Services Ltd | Other services | 2012 |
| JP Brothers Limited | Real estate | 2023 |
| JP Fashion Trends Limited | Manufacturing | 2018 |
| JP Logistics Delivery Limited | Transport & logistics | 2025 |
| JP Waste Ltd | Water & waste | 2026 |
| Jpcl Consulting Limited | Administrative & support | 2022 |
| JPL Residential Ltd | Real estate | 2022 |
| Jplewisuk Limited | Information & communication | 2017 |
| Jpme Trading Ltd | Health & social care | 2020 |
| Jpmsr Limited | Wholesale & retail | 2024 |
| Jptc Ltd | Real estate | 2025 |
| JR Financial Accountants Ltd | Professional & scientific | 2012 |
| JR Propss Ltd | Arts & recreation | 2025 |
| Jrbd Telco Ltd | Wholesale & retail | 2024 |
| Jrfa Ltd | Professional & scientific | 2022 |
| JRM Wealth Management Limited | Professional & scientific | 2016 |
| Jrpc Developments Limited | Construction | 2014 |
| JRR Development & Build Limited | Construction | 2024 |
| JRR Investments Limited | Construction | 2015 |
| JRR Technology Limited | Wholesale & retail | 2024 |
| JRS Consulting Services Limited | Professional & scientific | 2015 |
| JRS Finance Limited | Professional & scientific | 2017 |
| JS International Limited | Wholesale & retail | 1994 |
| JS Online Coaching Ltd | Other services | 2021 |
| JSA Newco Limited | Financial services | 2018 |
| JSA Property Partners LLP | | 2025 |
| JSA Services Limited | Extraterritorial | 2023 |
| JSD Design Consultancy Limited | Professional & scientific | 2026 |
| JSD71 Services Limited | Information & communication | 2019 |
| Jsgill Consultancy Ltd | Real estate | 2026 |
| JSJ Toothkind Limited | Health & social care | 2011 |
| Jslg International Limited | Administrative & support | 2010 |
| JSM Growth Ltd | Real estate | 2021 |
| JSM Growth NO 1 Ltd | Real estate | 2024 |
| JSM Properties Management Limited | Real estate | 2017 |
| JSM Trading Limited | Wholesale & retail | 2004 |
| JSN 3X Ltd | Real estate | 2021 |
| Jsn.M Ltd | Financial services | 2023 |
| Jsn.Pm Ltd | Real estate | 2023 |
| Jsnj Trading Ltd | Wholesale & retail | 2024 |
| JSP Security Ltd | Construction | 2025 |
| JSR Motor Company Ltd | Wholesale & retail | 2026 |
| Jsryan (UK) Ltd | Professional & scientific | 2016 |
| JSS CMA Limited | Professional & scientific | 2017 |
| JSS Performing Arts Ltd | Education | 2026 |
| Jstb Psychology Ltd | Education | 2024 |
| JSV Property Management Ltd | Real estate | 2017 |
| JT Services Cable Avoidance Ltd | Professional & scientific | 2021 |
| JTA Consulting Limited | Professional & scientific | 2008 |
| Jtbventures LP | | 2018 |
| Jtde Property Limited | Real estate | 2025 |
| JTJ Trading Limited | Wholesale & retail | 2010 |
| Jtkn Property Ltd | Real estate | 2026 |
| JU Consulting Ltd | Information & communication | 2025 |
| Juara Investments Limited | Real estate | 2021 |
| Jubidon Limited | Administrative & support | 2010 |
| Jublee Number 7 Limited | Financial services | 2020 |
| Judds Pharma Ltd | Wholesale & retail | 2022 |
| Jude London Ltd | Wholesale & retail | 2022 |
| Judi Drinks Ltd | Wholesale & retail | 2024 |
| Juggling Balls Limited | Professional & scientific | 2003 |
| Juice Junction Ltd | Hospitality | 2024 |
| Juice Solutions Ltd | Information & communication | 2012 |
| Julakay Ltd | Transport & logistics | 2015 |
| Jules Ford Publishing Ltd | Information & communication | 2022 |
| Juli-P Limited | Professional & scientific | 2025 |
| Julian Plastering Ltd | Construction | 2026 |
| Julian Thwaites & Company Limited | Wholesale & retail | 2001 |
| Julie Read Creative Ltd | Other services | 2026 |
| Juliet Cooks Ltd | Hospitality | 2024 |
| Jumbokath Limited | Professional & scientific | 2022 |
| Jump Economy Consulting Ltd | Professional & scientific | 2026 |
| Jump Sports Ltd | Arts & recreation | 1992 |
| Junction Cafe & Bestro Ltd | Hospitality | 2021 |
| Junction Dental Centre Ltd | Health & social care | 2023 |
| Junction Foods Limited | Hospitality | 2025 |
| Junction Motors Watford Ltd | Other services | 2014 |
| Junction News Ltd | Wholesale & retail | 2021 |
| June Plum Limited | Information & communication | 2015 |
| Juneidi Group Ltd | Real estate | 2021 |
| Jungle Spice Ltd | Hospitality | 2025 |
| Juniper 15 Limited | Information & communication | 2015 |
| Jupitech Limited | Information & communication | 2014 |
| Jupiter Decor Ltd | Wholesale & retail | 2022 |
| Juravle Ltd | Construction | 2019 |
| Just 4X4 Spares Limited | Wholesale & retail | 2015 |
| Just Have IT Limited | Professional & scientific | 2013 |
| Just Look Paradise Ltd | Arts & recreation | 2023 |
| Just Stuf Limited | Professional & scientific | 2000 |
| Just the Floor Ltd | Construction | 2022 |
| Just the Word Limited | Manufacturing | 2021 |
| JUST4JOBS Training and Consultancy Limited | Information & communication | 2010 |
| Justcareai Ltd | Public administration | 2025 |
| Justin Bayliss Limited | Information & communication | 2000 |
| Justin Park (Consulting) Ltd | Information & communication | 2015 |
| Justopened Ltd | Other services | 2005 |
| Justwatch UK Limited | Professional & scientific | 2019 |
| JV Contracting Ltd | Construction | 2025 |
| JV Traders Ltd | Wholesale & retail | 2021 |