| J C Utilities Dorset Ltd | Construction | 2023 |
| J D Cooper Electrical Ltd | Construction | 2017 |
| J J Xpress Ltd | Transport & logistics | 2007 |
| J K Management Design Limited | Professional & scientific | 2024 |
| J K Plant Services Midlands Ltd | Administrative & support | 2025 |
| J K Rotties Ltd | Agriculture & fishing | 2026 |
| J K Transport Services Midlands Ltd | Transport & logistics | 2026 |
| J L Surfacing Ltd | Construction | 2015 |
| J Mortimer Properties Ltd | Real estate | 2022 |
| J P Simpkiss & SON Limited | Administrative & support | 1992 |
| J Pugh Bathrooms Ltd | Construction | 2025 |
| J R K Construction Limited | Construction | 2022 |
| J R Wadhams Limited | Wholesale & retail | 1998 |
| J Renee Ltd | Real estate | 2023 |
| J S Company Ecom Ltd | Wholesale & retail | 2024 |
| J S Company Holding Ltd | Financial services | 2024 |
| J Syed & SON Ltd | Administrative & support | 2025 |
| J&A Homer Limited | Professional & scientific | 2025 |
| J&H Partnership Ltd | Arts & recreation | 2021 |
| J&S Street Food Limited | Hospitality | 2018 |
| J&S Training Services Ltd | Other services | 2018 |
| J&Smuir Limited | Health & social care | 2022 |
| J.& P.Supplies Limited | Wholesale & retail | 1975 |
| J.A.S.N Limited | Financial services | 2025 |
| J.A.Y. Engineering (Cradley) Limited | Administrative & support | 1968 |
| J.B. Adams & Partners Limited | Agriculture & fishing | 2005 |
| J.C.Webb(Kingswinford)Limited | Construction | 1965 |
| J.F Building & Landscaping Limited | Administrative & support | 2021 |
| J.I Trading Limited | Wholesale & retail | 2018 |
| J.M.J. Engineers Limited | Manufacturing | 1984 |
| J.S.Pipelines Limited | Construction | 2015 |
| J.Vernon Kendrick Limited | Other services | 1985 |
| JA Lewisvarley European Ltd | Transport & logistics | 2024 |
| Jabbamp Ltd | Professional & scientific | 2025 |
| Jabeen Akhtar Limited | Education | 2018 |
| Jacked Limited | Wholesale & retail | 2024 |
| Jackson & Penney Limited | Real estate | 2025 |
| Jackson Property Holdings Ltd | Construction | 2019 |
| Jacob Tipper Limited | Other services | 2022 |
| Jacqueline Blakey Interiors Limited | Professional & scientific | 2019 |
| Jade 888 Limited | Hospitality | 2026 |
| JAG Apparel Ltd | Wholesale & retail | 2021 |
| Jagdeep Sangha Limited | Health & social care | 2006 |
| Jagriti Limited | Health & social care | 2007 |
| JAH Real Estate Limited | Real estate | 2019 |
| JAI Housing Partners Ltd | Hospitality | 2018 |
| Jaipur Cottage Limited | Hospitality | 2015 |
| Jaks Mail Ltd | Wholesale & retail | 2023 |
| James Alexander Contracting Ltd | Construction | 2025 |
| James Close (Dudley) MAN Co Limited | Households | 2020 |
| James Doran - Webb Limited | Arts & recreation | 2012 |
| James Dowthwaite Ltd | Hospitality | 2016 |
| James Miles Ltd | Wholesale & retail | 2010 |
| Jamie Cotton Bespoke Estate Agent Services Limited | Real estate | 2021 |
| Jamtodayproperty Limited | Real estate | 2018 |
| JAN Lewis Limited | Hospitality | 1960 |
| Jane Broom Counselling Services Ltd | Administrative & support | 2019 |
| JAP Property Holdings Limited | Real estate | 2026 |
| Jarvis Healthcare Limited | Health & social care | 2025 |
| Javek Properties Limited | Real estate | 1985 |
| JAY COX Ltd | Professional & scientific | 2020 |
| JAY COX Property Ltd | Real estate | 2022 |
| Jayden Frank Limited | Administrative & support | 2015 |
| Jayne Willetts & Co Solicitors Limited | Professional & scientific | 2011 |
| Jays Engineering Supplies Limited | Professional & scientific | 2010 |
| Jays Sourcing Group Limited | Wholesale & retail | 1980 |
| JB Accident Repair Centre Ltd | Wholesale & retail | 2015 |
| JB Property Holding Limited | Real estate | 2003 |
| JB Residential Limited | Real estate | 2024 |
| JB Summer Property Ltd | Real estate | 2016 |
| JBC Propco Limited | Real estate | 2024 |
| JBD Housing Limited | Real estate | 2022 |
| JBJ Homes (Midlands) Limited | Construction | 2025 |
| Jbpr Limited | Professional & scientific | 2006 |
| JBS Builders WM Ltd | Construction | 2022 |
| JC & BC Holdings Limited | Financial services | 2011 |
| JCB Agencies Ltd | Administrative & support | 2005 |
| JCI Holdings Ltd | Wholesale & retail | 2023 |
| JD Comms Ltd | Information & communication | 2016 |
| JDH Mechanical Ltd | Construction | 2025 |
| JDN Safety and Security Ltd | Professional & scientific | 2026 |
| JE Property Solutions Ltd | Real estate | 2019 |
| JEM Decorators Limited | Construction | 2024 |
| Jembridge Property Limited | Real estate | 2017 |
| Jenica Construct Ltd | Construction | 2025 |
| Jenious Ltd | Health & social care | 2026 |
| Jennings Homer & Lynch Limited | Professional & scientific | 2013 |
| Jenson Trading Limited | Manufacturing | 2010 |
| Jesp Gases Limited | Financial services | 2016 |
| Jesp Limited | Professional & scientific | 2019 |
| Jessica & Joseph Hair Atelier Limited | Other services | 2025 |
| Jessica Shields Coaching Ltd | Administrative & support | 2024 |
| JET KIN Car Wash Ltd | Wholesale & retail | 2020 |
| JF AS Services Limited | Health & social care | 2025 |
| JFO Transport and Consultancy Ltd | Transport & logistics | 2023 |
| Jhal Limited | Hospitality | 2022 |
| JHB Financial Services Limited | Financial services | 2018 |
| JHL Management Ltd | Professional & scientific | 2025 |
| Jhon Curier Ltd | Transport & logistics | 2026 |
| Jhpe Consultancy Limited | Extraterritorial | 2022 |