| J P Landscapes & Construction Limited | Administrative & support | 2003 |
| J R Property (Midlands) Limited | Real estate | 2021 |
| J S D Roadside Developments Ltd | Construction | 2021 |
| J S M Building & Technical Services Ltd | Construction | 2012 |
| J&A Management Solutions Limited | Information & communication | 2016 |
| J&J Comms Limited | Construction | 2021 |
| J&R Group Holdings Ltd | Financial services | 2017 |
| J. & T. Bolas (Builders and Plumbers Merchants) Limited | Extraterritorial | 1974 |
| J. Bolas & SON Limited | Construction | 1974 |
| J. Lowe Building Services Limited | Other services | 2008 |
| J.C.Electrical & Mechanical Services Ltd | Construction | 2012 |
| J.H.R Technical Services Limited | Professional & scientific | 2013 |
| J.J. Sports Promotions Limited | Administrative & support | 2000 |
| J.Jenkins Property Limited | Real estate | 2020 |
| J.P. Film and Television Services Limited | Arts & recreation | 1977 |
| J.T. Jenkins Limited | Construction | 2022 |
| J.W.H Plastering Ltd | Construction | 2021 |
| J.W.Interiors Ltd | Construction | 2022 |
| J2GK Ltd | Other services | 2023 |
| J4MS Developments Ltd | Construction | 2023 |
| J5 Property Solutions Ltd | Construction | 2026 |
| JA Property Investments Ltd | Real estate | 2015 |
| JAB Travel Ltd | Administrative & support | 2017 |
| Jace Developments Ltd | Real estate | 2019 |
| Jace Rentals Ltd | Real estate | 2025 |
| Jack Europa Transpeed Ltd | Transport & logistics | 2012 |
| Jack Livesey Ceramics Limited | Extraterritorial | 2014 |
| Jack Livesey Tiles Limited | Extraterritorial | 2014 |
| Jack Owen MMA Limited | Arts & recreation | 2018 |
| Jackiewhooo Ltd | Transport & logistics | 2025 |
| Jackron TCL Ltd | Hospitality | 2025 |
| Jacqueline Cross Photography Limited | Professional & scientific | 2015 |
| Jada Solutions Limited | Wholesale & retail | 2022 |
| JAM JAM Caribbean Takeaway Limited | Hospitality | 2022 |
| JAM Leisure Limited | Hospitality | 2024 |
| Jamaican Heritage UK CIC | Education | 2023 |
| James Evans & Associates Limited | Financial services | 2011 |
| James Evans Financial Services Limited | Financial services | 2011 |
| James Evans Holdings Limited | Financial services | 2025 |
| Jamie Taylor Consulting Limited | Wholesale & retail | 2021 |
| Jane Louise Freer Limited | Extraterritorial | 2024 |
| JAR ENG Ltd | Professional & scientific | 2024 |
| JAS Bajwa Holding Ltd | Financial services | 2024 |
| JAS Trading Business Ltd | Wholesale & retail | 2017 |
| Jason Jones Limited | Construction | 2003 |
| JAY Kandola Property Limited | Real estate | 2024 |
| Jaybee (Windows and Glazing) Limited | Manufacturing | 2003 |
| Jaycee Project Management Ltd | Professional & scientific | 2010 |
| Jaykay Systems Limited | Wholesale & retail | 2025 |
| Jaykey Limited | Professional & scientific | 2012 |
| JB Allport Services Limited | Construction | 2026 |
| JB Building Services (Cannock) Limited | Construction | 2015 |
| JBB M & E Services Ltd | Manufacturing | 2023 |
| Jblab Products Ltd | Wholesale & retail | 2024 |
| JBM Developments Ltd | Construction | 2020 |
| JBZ Enterprise Ltd | Hospitality | 2023 |
| JC Decor Ltd | Construction | 2026 |
| JC Race Solutions Ltd | Professional & scientific | 2014 |
| JC1 Group Ltd | Construction | 2024 |
| JCA UK Holdings Limited | Professional & scientific | 2023 |
| JD Airsoft Limited | Arts & recreation | 2008 |
| Jddp Limited | Professional & scientific | 2025 |
| Jdmac Services Ltd | Manufacturing | 2020 |
| JDS Euro Transport & Removals Limited | Transport & logistics | 2024 |
| Jebel Marketing Ltd | Professional & scientific | 2023 |
| Jedi Collectables Limited | Wholesale & retail | 2018 |
| Jefferies Holdings Limited | Financial services | 2015 |
| Jefh Services Limited | Information & communication | 2025 |
| JEK Foods Limited | Hospitality | 2022 |
| Jekk Foods Limited | Hospitality | 2024 |
| Jenkins Motor Company Limited | Wholesale & retail | 2016 |
| Jenkins Property Development Limited | Real estate | 2025 |
| Jenpen Ltd | Health & social care | 2012 |
| Jessica's Canteen and Vending Solutions Limited | Wholesale & retail | 2017 |
| JFW Midlands Limited | Construction | 2024 |
| JG Aerial Solutions Limited | Professional & scientific | 2025 |
| Jhahh Limited | Real estate | 2021 |
| JHD Management Limited | Construction | 2022 |
| Jibrail Property Solutions Ltd | Real estate | 2025 |
| Jigsaw's Kids Club Limited | Education | 2010 |
| JJ EST8 Limited | Real estate | 2021 |
| JJH Plastering Ltd | Construction | 2021 |
| JJP Building Services Limited | Construction | 2015 |
| JJP Developments Ltd | Construction | 2022 |
| JL Developments (2024) Limited | Real estate | 2024 |
| JLB Carpentry Limited | Construction | 2015 |
| JLC Interiors Limited | Manufacturing | 2018 |
| JLE Page Education Limited | Education | 2023 |
| JMB Compliance Ltd | Transport & logistics | 2021 |
| JMB Engineering Limited | Construction | 2003 |
| JMD Properties (Midlands) Ltd | Real estate | 2024 |
| JMS Financial & Legal Limited | Financial services | 2022 |
| JMT Transport (UK) Limited | Transport & logistics | 2012 |
| JN Staging Ltd | Professional & scientific | 2025 |
| JO Bates Mortgage Services Ltd | Financial services | 2022 |
| JO Cadman Consulting Ltd | Professional & scientific | 2022 |
| JO Williams Consultancy Limited | Professional & scientific | 2026 |
| Joallenboden Ltd | Administrative & support | 2025 |
| Joaw Limited | Administrative & support | 2019 |
| Jobs MCR Limited | Administrative & support | 2021 |