| J&J Consultancy UK Ltd | Other services | 2017 |
| J&J Corporate Limited | Financial services | 2019 |
| J&S NK Limited | Wholesale & retail | 2021 |
| J.C.R. Driving Services Ltd | Transport & logistics | 2015 |
| J.S. Property Company Limited | Construction | 1987 |
| J3 Design & Build Ltd | Construction | 2025 |
| Jabez Energy Ltd | Wholesale & retail | 2014 |
| Jack Doug Ltd | Other services | 2018 |
| Jacobs Island Ltd | Wholesale & retail | 2017 |
| Jade Travel Ltd | Transport & logistics | 2023 |
| Jags Consultancy Ltd | Information & communication | 2015 |
| Jahandhs Ltd | Wholesale & retail | 2026 |
| Jahthai Epicurean Group Ltd | Hospitality | 2025 |
| JAI RAO Ltd | Health & social care | 2023 |
| Jaiveen Food & Wine Ltd | Wholesale & retail | 2019 |
| JAK JAK Ltd | Administrative & support | 2021 |
| Jake Feather Hotels Limited | Financial services | 1996 |
| Jamia Masjid West Drayton Trust | Health & social care | 2015 |
| Jamway Limited | Professional & scientific | 2021 |
| JAN Cars Limited | Wholesale & retail | 2017 |
| JAS Internet Cafe Limited | Information & communication | 2012 |
| Jasmine Store Ltd | Wholesale & retail | 2026 |
| Jason&Jashari Ltd. | Transport & logistics | 2014 |
| Jasreen Homes Limited | Real estate | 2024 |
| Jass Logistics Ltd | Transport & logistics | 2025 |
| Jasvinder Singh Limited | Construction | 2024 |
| JAY ESS Construction PVT Limited | Construction | 2016 |
| JAY ESS EMM Ltd | Information & communication | 2017 |
| JAY Maharaj Pharma Ltd | Financial services | 2018 |
| JAY Palmer Ltd | Manufacturing | 2022 |
| JAY R Tech Limited | Information & communication | 2010 |
| JB Spray Ltd | Professional & scientific | 2018 |
| JBS Solutions Ltd | Wholesale & retail | 2025 |
| Jbyratransport Ltd | Transport & logistics | 2014 |
| JC Customs Limited | Wholesale & retail | 2020 |
| JC Customz Ltd | Wholesale & retail | 2018 |
| JC Skips Limited | Transport & logistics | 2025 |
| JD Acoustics Ltd | Professional & scientific | 2024 |
| JD Lomba Limited | Manufacturing | 2026 |
| Jebify Direct Ltd | Construction | 2015 |
| Jehovah Jireh Security Services Ltd | Administrative & support | 2021 |
| Jejoneli Ltd | Health & social care | 2025 |
| Jenni and KAN PVT Limited | Real estate | 2021 |
| Jeno Engineering Ltd | Construction | 2014 |
| Jesel Ltd | Wholesale & retail | 2007 |
| Jetsave Limited | Administrative & support | 2000 |
| JF Law (London) Ltd | Professional & scientific | 2023 |
| JGT Capital Ltd. | Financial services | 2013 |
| Jhony Construction Ltd | Construction | 2022 |
| Jigjiga Limited | Transport & logistics | 2024 |
| Jimmys Autos Ltd | Other services | 2014 |
| Jinnah Services Ltd | Wholesale & retail | 2021 |
| JJ Collections Ltd | Other services | 2018 |
| JJ Dwelling Ltd | Households | 2024 |
| JJD Kitchens and Joinery Ltd | Construction | 2026 |
| JJE Alliance Ltd | Information & communication | 2025 |
| JK & LK Enterprises Ltd | Health & social care | 2018 |
| JK Corporate Holdings Limited | Financial services | 2024 |
| JK Investments Limited | Real estate | 2005 |
| Jlrefurb Ltd | Construction | 2022 |
| JM Global Trading.Com Ltd | Wholesale & retail | 2016 |
| JME Propty Ltd | Real estate | 2019 |
| JMK Logistics Limited | Transport & logistics | 2011 |
| Jmrps Limited | Information & communication | 2022 |
| JNT Logistics Ltd | Transport & logistics | 2019 |
| JOE Adam Construction Ltd | Administrative & support | 2018 |
| John Gilliland Limited | Construction | 2017 |
| John Guest International Limited | Financial services | 1999 |
| Johnson & Grant Limited | Real estate | 2017 |
| Jolly Rainbows Nursery Ltd | Health & social care | 2014 |
| Joops Ltd | Professional & scientific | 2020 |
| Jose Services Limited | Other services | 2009 |
| Josh Phillips Limited | Education | 2021 |
| Joshar Group Ltd | Information & communication | 2019 |
| JOT Constructions Limited | Construction | 2009 |
| Journeys Asia Limited | Administrative & support | 2016 |
| JP Amusement Ltd | Other services | 2025 |
| JP Mcgrath Construction Ltd | Construction | 2015 |
| JPJ Thiru Ltd | Other services | 2022 |
| JPR Holdings Ltd | Real estate | 2024 |
| JR Snacks Ltd | Hospitality | 2023 |
| JS Company Finance Limited | Financial services | 2023 |
| JS SOLUTION1 Ltd | Administrative & support | 2023 |
| JS Trading Ltd | Wholesale & retail | 2025 |
| JS7 Service Ltd | Construction | 2025 |
| JSQ Limited | Hospitality | 2025 |
| JSR Plans Ltd | Construction | 2023 |
| JSR Works and Company Ltd | Transport & logistics | 2025 |
| JT Decorating Ltd | Construction | 2024 |
| JT Traders Ltd | Hospitality | 2015 |
| Jubilee Power Limited | Administrative & support | 2006 |
| Juls Dank Limited | Wholesale & retail | 2024 |
| Jumbo Crayon Ltd | Professional & scientific | 2013 |
| Jurie & Kadi Ltd | Real estate | 2021 |
| Just Seats Ltd | Wholesale & retail | 2025 |
| Just Tyre-Ing Ltd | Wholesale & retail | 2025 |
| Justorange Ltd | Manufacturing | 2021 |
| Jutt Transport Ltd | Transport & logistics | 2022 |
| JV Arts Ltd | Transport & logistics | 2025 |
| JV Carpentry Limited | Construction | 2017 |