| J Wojcik Trans Ltd | Transport & logistics | 2025 |
| J&I Investments Limited | Real estate | 2021 |
| J&K Dream Beauty Ltd | Other services | 2022 |
| J&M Drainage Jetting & Cctv Systems Ltd | Professional & scientific | 2023 |
| J&M Groundworks & Civils (Coventry) Ltd | Construction | 2026 |
| J&M Groundworks Coventry Ltd | Construction | 2019 |
| J&P Ward Ltd | Agriculture & fishing | 2019 |
| J&R Self Storage Chesham Ltd | Wholesale & retail | 2025 |
| J&R Self-Storage Nuneaton Ltd | Wholesale & retail | 2023 |
| J. a. W. Joinery & Building Services Ltd | Manufacturing | 2010 |
| J. a. Young Construction Limited | Construction | 2005 |
| J. and J. Negus Limited | Wholesale & retail | 1974 |
| J. G. News, Food & Wine Limited | Wholesale & retail | 2006 |
| J. R. Turner Building Contractors Limited | Construction | 2012 |
| J.D.S. Wiring Limited | Construction | 2007 |
| J.F. Tiling Ltd | Construction | 2011 |
| J.G Kowalski Ltd | Transport & logistics | 2025 |
| J.J. Churchill (Holdings) Limited | Financial services | 2020 |
| J.J.Churchill Limited | Manufacturing | 1937 |
| J.Wright HSE Ltd | Professional & scientific | 2022 |
| J3D Design & Imaging Limited | Information & communication | 2002 |
| J3M Properties Limited | Real estate | 2020 |
| J4 Holdings Ltd | Real estate | 2020 |
| JAB Kitchens Ltd | Construction | 2015 |
| JAB Tyres & Exhausts Ltd | Wholesale & retail | 2003 |
| Jack Eden Financial Solutions Ltd | Financial services | 2017 |
| Jacks Entertainment Ltd | Hospitality | 2013 |
| Jackson Construction Services Ltd | Construction | 2025 |
| Jacksons of Old Arley Limited | Wholesale & retail | 2011 |
| Jacob's Workshop Ltd | Construction | 2022 |
| Jades Hair and Beauty (Midlands) Ltd | Other services | 2015 |
| Jaege Smart Turn Limited | Manufacturing | 2010 |
| JAG Distribution Logistics Limited | Transport & logistics | 2017 |
| Jaggi Builder Limited | Construction | 2020 |
| Jagsland Ltd | Wholesale & retail | 2020 |
| Jahsa Locums Ltd | Health & social care | 2012 |
| Jaison Ltd | Health & social care | 2022 |
| Jake Oconnor Ltd | Wholesale & retail | 2024 |
| Jakuzi Entertainment Limited | Information & communication | 2021 |
| Jalil Ahmed Investments Ltd | Real estate | 2018 |
| James Arthur Properties Ltd | Real estate | 2025 |
| James Baxter Limited | Agriculture & fishing | 1963 |
| James Blacklaws Limited | Administrative & support | 2015 |
| James Commercials Limited | Wholesale & retail | 2003 |
| James Munday Rise Management Company Ltd | Households | 2019 |
| James Scott Services Limited | Agriculture & fishing | 2012 |
| James Stanworth Limited | Wholesale & retail | 2015 |
| Jamia Estates Development Ltd | Construction | 2019 |
| Jamie Jones Enterprises Limited | Arts & recreation | 2019 |
| Jane's Hair Design Limited | Other services | 2015 |
| Janissary Interviews Limited | Education | 2024 |
| Janix Technologies Limited | Professional & scientific | 2016 |
| Jaques Innovations Limited | Wholesale & retail | 2014 |
| Jash Off-Licence Ltd | Wholesale & retail | 2023 |
| Jasmynwilson Ltd | Wholesale & retail | 2025 |
| Jason Rice I-Care Limited | Health & social care | 2003 |
| Jason Watts Electrical Limited | Construction | 2018 |
| Jaspers of Hinckley Limited | Wholesale & retail | 2019 |
| Jassarlogistics Ltd | Transport & logistics | 2026 |
| Jassarsahib Ltd | Administrative & support | 2026 |
| JAT Happy Shop Ltd | Wholesale & retail | 2026 |
| JAW Earthworks Limited | Construction | 2000 |
| JAY Security & Events Ltd | Administrative & support | 2018 |
| Jazzmont Limited | Construction | 2005 |
| JB Estates Ltd | Real estate | 2007 |
| JB Windows and Doors Installation Limited | Construction | 2023 |
| Jbmfs Ltd. | Agriculture & fishing | 2017 |
| Jbmps Limited | Other services | 2006 |
| JBR Engineering Supplies Limited | Administrative & support | 2022 |
| JC Compressors Ltd | Manufacturing | 2025 |
| JC Media Ltd | Information & communication | 2011 |
| JCH Management & Safety Consultants Ltd | Professional & scientific | 2023 |
| JCJ Ceramics Ltd | Construction | 2008 |
| Jckrishna Limited | Real estate | 2020 |
| Jcmovements Ltd | Transport & logistics | 2025 |
| JCW Electrical Installations Ltd | Construction | 2022 |
| JD Flooring Ltd | Construction | 2021 |
| JDM Building Limited | Construction | 2019 |
| JDR Products Limited | Manufacturing | 1980 |
| Jeanes Consulting Services Limited | Information & communication | 2015 |
| Jems Hair Design Limited | Other services | 2025 |
| Jennings Gym Equipment Limited | Wholesale & retail | 2021 |
| Jensen Automotive Holdings Limited | Extraterritorial | 2014 |
| Jensen Automotive Limited | Extraterritorial | 2014 |
| Jensen Car Company Limited | Extraterritorial | 2018 |
| Jensen Classic Car Limited | Extraterritorial | 2014 |
| Jensen Healey Automotive Limited | Extraterritorial | 2014 |
| Jensen Interceptor Limited | Extraterritorial | 2014 |
| Jensen Motors Limited | Extraterritorial | 2017 |
| Jensen Parts and Service Limited | Extraterritorial | 2014 |
| Jensen Sports Car Limited | Extraterritorial | 2014 |
| Jerie&Sons Limited | Administrative & support | 2025 |
| Jessica's Wellness & Retreat Ltd | Other services | 2025 |
| Jewel Holdings Limited | Professional & scientific | 2020 |
| Jewel Workspace Limited | Administrative & support | 2024 |
| Jezzard Properties Ltd | Real estate | 2023 |
| JF QS and Site Services Ltd | Professional & scientific | 2017 |
| JFW Music LLP | | 2023 |
| JG Customer Services Limited | Administrative & support | 2009 |
| JG Dermatology Limited | Health & social care | 2019 |