| IWM Property Group Ltd | Real estate | 2024 |
| Izma Productions Ltd | Hospitality | 2025 |
| J & D Property Maintenance Ltd | Construction | 2024 |
| J & M Contracts International Limited | Arts & recreation | 2003 |
| J & M Pattern & DIE Company Limited | Administrative & support | 2003 |
| J & N Design and Build Ltd | Construction | 2019 |
| J a Transport Innovation Limited | Transport & logistics | 2026 |
| J a V Grazebrook & Co Limited | Manufacturing | 2015 |
| J B Infrastructure and Construction Ltd | Construction | 2018 |
| J C Engineering Services Limited | Professional & scientific | 2024 |
| J D Sprinkler Solutions Ltd | Other services | 2025 |
| J Freeman and SON (Netherton) Limited | Other services | 1967 |
| J H COX LLP | | 2014 |
| J H Services 2020 Ltd | Extraterritorial | 2020 |
| J I Properly Limited | Real estate | 2025 |
| J J Emmanoch Ltd | Health & social care | 2023 |
| J J Hadley Property Solutions Ltd | Real estate | 2024 |
| J J Hodgetts Limited | Construction | 2013 |
| J L Hawkes Home Improvements Ltd | Construction | 2014 |
| J P C G Holdings Ltd | Real estate | 2019 |
| J P C G Limited | Other services | 2019 |
| J P Complete Groundworks Ltd | Administrative & support | 2017 |
| J P Courier Limited | Transport & logistics | 2025 |
| J P Gardening Services Ltd | Administrative & support | 2024 |
| J P Taylor Surveyors & Property Managers Limited | Real estate | 2017 |
| J R Associates (Safety) Limited | Public administration | 2005 |
| J R Fleet Solutions 2023 Ltd | Wholesale & retail | 2023 |
| J S Property (West Midlands) Ltd | Construction | 2015 |
| J S T Retail Ltd | Wholesale & retail | 2025 |
| J Thompson Limited | Information & communication | 2012 |
| J W Dunn Building Services Limited | Construction | 2009 |
| J W Dunn Holdings Ltd | Financial services | 2019 |
| J W Dunn Properties Ltd | Real estate | 2021 |
| J W Flooring Limited | Construction | 2012 |
| J W Personal Training Ltd | Arts & recreation | 2021 |
| J Waldron Fitter-Rigger Limited | Manufacturing | 2018 |
| J Yates Consulting Ltd | Information & communication | 2024 |
| J&J Vehicle Services Ltd | Wholesale & retail | 2020 |
| J&L Improvements Limited | Construction | 2025 |
| J&S Decorating and Property Maintenance Limited | Construction | 2023 |
| J-Jay Upholstery Limited | Water & waste | 1982 |
| J. Marklew Engineering Limited | Manufacturing | 1983 |
| J.A.C. (Midlands) Limited | Construction | 2024 |
| J.Gam Salvage and Recovery Limited | Wholesale & retail | 2024 |
| J.J.Field and Company Limited | Transport & logistics | 1962 |
| J.Jones Prototyping and Development Ltd | Manufacturing | 2025 |
| J.P. Thomson Properties Limited | Extraterritorial | 1981 |
| J.P.S. Construction Limited | Construction | 1997 |
| J.S.Propertiesuk Ltd | Real estate | 2020 |
| J5 Fitness Limited | Wholesale & retail | 2020 |
| JA & KSH Logistics Ltd | Transport & logistics | 2019 |
| JAA Developments Group Ltd | Construction | 2025 |
| Jack 139 Limited | Hospitality | 2017 |
| Jack Mills Workplace Solutions Ltd | Other services | 2025 |
| Jackson Brothers Capacitors Ltd | Manufacturing | 2017 |
| Jackson Studios Ltd | Construction | 2016 |
| Jacob & Oliver Ltd | Professional & scientific | 2026 |
| Jade Blossom Limited | Health & social care | 2018 |
| Jagromaras Ltd | Health & social care | 2023 |
| Jaiharsh Homes Ltd | Real estate | 2023 |
| Jaiharsh Pharma Limited | Wholesale & retail | 2017 |
| Jain & Sons Properties Ltd | Financial services | 2015 |
| Jake Management Ltd | Real estate | 2024 |
| Jalm Services Ltd | Health & social care | 2020 |
| James Hemming Electrical Limited | Manufacturing | 2012 |
| James Woodward Electrical Services Limited | Construction | 2025 |
| Jamian Cleaning Services Limited Ltd. | Administrative & support | 2021 |
| JAN Challenor Career Coaching Limited | Education | 2025 |
| Janest Builders Ltd | Construction | 2026 |
| JAR Resources Ltd | Administrative & support | 2023 |
| Jarv Limited | Information & communication | 2024 |
| Jatt Life Global Ltd | Financial services | 2021 |
| Jatt Xpress Ltd | Transport & logistics | 2022 |
| JAY Home FIX Ltd | Construction | 2026 |
| JAY Nicklin Haulage Limited | Transport & logistics | 2016 |
| Jay&J Ltd | Wholesale & retail | 2022 |
| JB Links International Limited | Administrative & support | 2011 |
| Jbem Properties Limited | Real estate | 2025 |
| JBJ Brickwork Ltd | Construction | 2026 |
| JBM Heating and Plumbing Ltd | Construction | 2025 |
| JBV Property Limited | Real estate | 2024 |
| JC & HC Holdings Ltd | Financial services | 2025 |
| JC Estates (Midlands) Limited | Administrative & support | 2017 |
| JCA Transport Ltd | Transport & logistics | 2022 |
| Jcml Collections Limited | Administrative & support | 2018 |
| JCS Caravan Services Limited | Wholesale & retail | 2026 |
| JCS Friuts Limited | Wholesale & retail | 2018 |
| JD Bear Holding Company Limited | Real estate | 2009 |
| JDL Project Management Ltd | Professional & scientific | 2019 |
| JE T'Aime Limited | Wholesale & retail | 2011 |
| Jeevan Pharma Limited | Wholesale & retail | 2018 |
| JEM Joinery Midlands Ltd | Manufacturing | 2016 |
| JEN Consultancy Services Limited | Professional & scientific | 2023 |
| Jenrus Homes Ltd | Construction | 2024 |
| Jensen Autos Limited | Wholesale & retail | 2026 |
| Jensen Personal Leathergoods Limited | Wholesale & retail | 2024 |
| Jeonline Ltd | Wholesale & retail | 2022 |
| Jerk and Juicee Limited | Hospitality | 2026 |
| Jerk to Juice Limited | Hospitality | 2026 |
| JES Comms Limited | Construction | 2021 |