| J D Hirst Services Limited | Transport & logistics | 2010 |
| J E Monk Ltd | Administrative & support | 2021 |
| J E Mynott Limited | Education | 2015 |
| J E Protrans Limited | Administrative & support | 2016 |
| J Edgar Limited | Water & waste | 2014 |
| J G Marine Services Ltd | Manufacturing | 2018 |
| J G Sinclair Ltd | Professional & scientific | 2015 |
| J H & N J Foxon Limited | Agriculture & fishing | 2017 |
| J Kelly Haulage Ltd | Transport & logistics | 2026 |
| J M P Driver Hire Limited | Transport & logistics | 2017 |
| J Miller Transport Ltd | Transport & logistics | 2021 |
| J Miners Cars Limited | Wholesale & retail | 2013 |
| J P Smith Transport Limited | Transport & logistics | 2017 |
| J R Kehoe Building Services Limited | Construction | 2024 |
| J Train Ltd | Construction | 2024 |
| J Valentine Limited | Administrative & support | 2015 |
| J Van Driel Services Ltd | Transport & logistics | 2018 |
| J&F Investments Limited | Professional & scientific | 2020 |
| J&F Property Lettings Ltd | Real estate | 2019 |
| J&F Property Limited | Real estate | 2018 |
| J&Ngrouppb Limited | Hospitality | 2024 |
| J&T Healthcare Ltd | Administrative & support | 2019 |
| J&T West Limited | Hospitality | 2025 |
| J. Morn Ltd | Professional & scientific | 2025 |
| J.Breeze Ltd | Construction | 2026 |
| J.D. Opulence Ltd. | Construction | 2020 |
| J.V.Lloyd | Agriculture & fishing | 1959 |
| JAB Rugby Aviation Ltd | Manufacturing | 2023 |
| Jack Kelly Brickwork Ltd. | Construction | 2016 |
| Jackson Independent Trading Limited | Transport & logistics | 2014 |
| Jackson Roberts Consulting Limited | Professional & scientific | 2016 |
| Jadhav Limited | Health & social care | 2014 |
| Jaffsco Ltd | Transport & logistics | 2024 |
| Jagannath Foods Limited | Hospitality | 2025 |
| Jage Properties Limited | Real estate | 2022 |
| Jake Tech Ltd | Professional & scientific | 2022 |
| Jamal Cromwell Recruitment Ltd | Professional & scientific | 2024 |
| Jamal Social Work Assessments Ltd | Health & social care | 2024 |
| James & Browne (Insurance Brokers) Ltd. | Financial services | 1980 |
| James Civils Plant Hire Ltd | Administrative & support | 2023 |
| James Clare Studio Ltd | Professional & scientific | 2019 |
| James Commercial Operations (U.K.) Limited | Professional & scientific | 1992 |
| James Court Creative Solutions Ltd | Professional & scientific | 2019 |
| James Goodwin Ltd | Professional & scientific | 2012 |
| James Harrison Service's Ltd | Wholesale & retail | 2023 |
| James Mcdonald FI UK Ltd | Public administration | 2023 |
| James Mowbray Transport Limited | Transport & logistics | 2015 |
| Jamie Green Promotions Limited | Other services | 2002 |
| Jamoo Trading Ltd | Wholesale & retail | 2022 |
| Jams Retail Group Ltd | Wholesale & retail | 2026 |
| Jandu Logistics Ltd | Transport & logistics | 2017 |
| Jane Compton Management Limited | Arts & recreation | 2013 |
| Jane's Fuel Supplies Ltd | Wholesale & retail | 2020 |
| Janina Limited | Professional & scientific | 2017 |
| Janode Consult Limited | Construction | 2024 |
| Jantomarna Therapeutics Limited | Professional & scientific | 2025 |
| Janus Lean Leadership Limited | Administrative & support | 2007 |
| Jany Transport Ltd | Transport & logistics | 2017 |
| JAP Scrap Ltd | Wholesale & retail | 2024 |
| Japanese Dream Machines Ltd | Wholesale & retail | 2025 |
| Jariz Investments Limited | Real estate | 2024 |
| Jarlu Properties Ltd | Real estate | 2025 |
| Jarvis & Co Property Ltd | Real estate | 2023 |
| Jarvis AID Ltd | Hospitality | 2023 |
| Jarvis Security Ltd | Administrative & support | 2022 |
| JAS Management (Rugby) Ltd | Real estate | 2021 |
| Jasdev Properties Limited | Real estate | 2025 |
| Jason Tysoe Limited | Agriculture & fishing | 2009 |
| JAY Mechanical Services Limited | Construction | 2019 |
| Jaystar Inc Ltd | Real estate | 2022 |
| JB Fluid Control Limited | Financial services | 2025 |
| JB Luxury Escapes Ltd | Administrative & support | 2022 |
| JB Property Agents Ltd | Real estate | 2023 |
| JBD (Health & Beauty) Limited | Wholesale & retail | 2011 |
| Jbit Technologies Ltd | Information & communication | 2024 |
| JBK Bespoke Tutoring Ltd | Education | 2025 |
| JBN Rugby Ltd | Manufacturing | 2021 |
| JBS 1905 Ltd | Real estate | 2025 |
| JC Flagg Ltd | Information & communication | 2023 |
| JC Property Improvements Ltd | Construction | 2023 |
| JCD Hair Ltd | Other services | 2016 |
| JCE Transport Limited | Transport & logistics | 2012 |
| JCH European Limited | Transport & logistics | 2024 |
| JD Fabrications (Rugby) Limited | Construction | 2021 |
| JD House Repairs and Improvements Limited | Construction | 2025 |
| JD Property Enterprises Ltd | Real estate | 2018 |
| JDA (Leicester) Limited | Transport & logistics | 2013 |
| JDH Enterprises Ltd | Wholesale & retail | 2012 |
| Jdrm Ltd | Real estate | 2024 |
| Jebac Biede Limited | Transport & logistics | 2021 |
| Jeffrey Bernhard & Sons Limited | Real estate | 1959 |
| Jeffries Farm Ltd | Agriculture & fishing | 2015 |
| Jelex Ltd | Transport & logistics | 2024 |
| Jellybone Limited | Information & communication | 2013 |
| Jellywell Ltd | Financial services | 2022 |
| Jema Limited | Real estate | 2021 |
| Jems Photography Limited | Professional & scientific | 2014 |
| Jencare Services Limited | Health & social care | 2024 |
| Jeneve Properties Ltd | Real estate | 2021 |
| Jenny Walters Ltd | Information & communication | 2026 |