| Jaml Limited | Health & social care | 2021 |
| Jamm Hair, Beauty,Nails. Limited | Other services | 2013 |
| JAN & Quill Ltd | Professional & scientific | 2022 |
| JAN Car Wash Ltd | Administrative & support | 2018 |
| Jandu Dental Ltd | Health & social care | 2020 |
| Jane Hooper Limited | Professional & scientific | 2019 |
| Jane Jones Design Limited | Professional & scientific | 2012 |
| Jane, Saunders & Manning Limited | Manufacturing | 1973 |
| Jangu Properties Limited | Real estate | 2016 |
| Janoel Property Limited | Real estate | 2024 |
| JAR Accommodation Service Limited | Real estate | 2023 |
| JAR Pharma Ltd | Wholesale & retail | 2020 |
| Jardin Binfield Ltd | Households | 2017 |
| Jardon Management Services Limited | Extraterritorial | 2009 |
| JAS Sanghera Aesthetics Ltd | Other services | 2023 |
| Jasa Group Limited | Real estate | 2024 |
| Jask Creative Limited | Professional & scientific | 2002 |
| Jasper Insight Ltd | Administrative & support | 2014 |
| Jatre Ltd | Wholesale & retail | 2022 |
| Javed & Co INT Ltd | Wholesale & retail | 2009 |
| JAY Ambe Foods T/A Niya’S Kitchen Ltd | Hospitality | 2024 |
| JAY IT Ltd | Information & communication | 2018 |
| JAY M Properties Ltd | Real estate | 2019 |
| JAY M Services Ltd | Financial services | 2020 |
| Jayco Insulation Services Ltd | Construction | 2014 |
| Jaymia Distribution Ltd | Wholesale & retail | 2023 |
| JB 101 Ltd | Real estate | 2025 |
| JB 102 Ltd | Real estate | 2025 |
| JB 103 Ltd | Real estate | 2025 |
| JB 104 Ltd | Real estate | 2025 |
| JB 105 Ltd | Real estate | 2025 |
| JB 106 Ltd | Real estate | 2025 |
| JB 107 Ltd | Real estate | 2025 |
| JB Assured Property Trading Ltd | Real estate | 2021 |
| JB Comms Ltd | Information & communication | 2011 |
| JB Forklifts Limited | Administrative & support | 2007 |
| JB IT Services Ltd | Information & communication | 2025 |
| JB Property Accounting Limited | Professional & scientific | 2013 |
| JB Technology Services Limited | Professional & scientific | 2014 |
| JBA Medical Education Ltd | Education | 2025 |
| JC Building Limited | Construction | 2019 |
| JC Construction Birmingham Ltd | Construction | 2026 |
| JC Football Academy Ltd | Arts & recreation | 2024 |
| JC Master Trading Ltd | Wholesale & retail | 2025 |
| JC Midlands Electrical Ltd | Construction | 2022 |
| JC Rhoden Holdings Ltd | Construction | 2016 |
| JCA Cares Ltd | Health & social care | 2025 |
| JCB Padel Ltd | Arts & recreation | 2024 |
| JCL Prestigious Motors Limited | Wholesale & retail | 2019 |
| JCM Medical Limited | Education | 2021 |
| Jcmj Limited | Real estate | 2017 |
| JCMJ2 Limited | Real estate | 2025 |
| JCMJ3 Limited | Construction | 2025 |
| Jcnewman Limited | Real estate | 2018 |
| Jcomm Limited | Wholesale & retail | 2015 |
| Jcos Property Ltd | Real estate | 2023 |
| JCP Advisory Ltd | Professional & scientific | 2026 |
| JCQ Fitness Limited | Arts & recreation | 2013 |
| Jcqs Services Ltd | Professional & scientific | 2024 |
| JD 812 Limited | Financial services | 2015 |
| JD Consultio/Consultious Ltd | Professional & scientific | 2018 |
| JD Land Limited | Financial services | 2025 |
| JD Neurology Ltd | Health & social care | 2024 |
| JD Validations Ltd | Professional & scientific | 2017 |
| JDB Premier Plastering Ltd | Construction | 2021 |
| Jdba Limited | Professional & scientific | 2010 |
| JDC Property Maintenance Limited | Construction | 2025 |
| JDF Communications Limited | Professional & scientific | 2010 |
| JDH Build Ltd | Construction | 2022 |
| JDH Building Solutions Ltd | Construction | 2025 |
| JDH Estates Ltd | Real estate | 2024 |
| JDH Interior Renovations Ltd | Construction | 2022 |
| JDJ 1966 Consultancy Limited | Education | 2024 |
| JDM BID Ltd | Wholesale & retail | 2025 |
| JDM Building & Property Maintenance Limited | Construction | 2010 |
| JDM Gearbox Repairs Limited | Wholesale & retail | 2016 |
| Jdrp Limited | Real estate | 2025 |
| JDW Project Management Ltd | Professional & scientific | 2022 |
| Jealous Creations Limited | Arts & recreation | 2021 |
| Jean Philippe Montvell Limited | Wholesale & retail | 2025 |
| Jean Pousson and Associates Limited | Administrative & support | 2010 |
| JEC & LJC Ltd | Financial services | 2020 |
| Jehurst Limited | Professional & scientific | 2014 |
| JEM Properties & Investments Limited | Other services | 2016 |
| Jemco Corporate Solutions Ltd | Transport & logistics | 2023 |
| Jemsoft (UK) Limited | Information & communication | 2003 |
| Jenner Consulting Ltd | Administrative & support | 2026 |
| Jennifer Lauren Gallery Limited | Wholesale & retail | 2020 |
| Jernoiu Ltd | Health & social care | 2022 |
| Jerrom Secretarial Services Limited | Professional & scientific | 2003 |
| Jerroms Business Solutions Limited | Professional & scientific | 2014 |
| Jerroms Financial Planning Ltd | Administrative & support | 2003 |
| Jerroms GCN Limited | Professional & scientific | 2013 |
| Jerroms Holdings Limited | Financial services | 2019 |
| Jerroms Mortgage & Finance Ltd | Financial services | 2018 |
| Jerroms Solutions Limited | Administrative & support | 2006 |
| Jerroms Specialist Tax Services Ltd | Professional & scientific | 2022 |
| JES Group (Holdings) Ltd | Professional & scientific | 2025 |
| JES Investments Limited | Real estate | 2008 |
| Jesper Hogg Ltd | Professional & scientific | 2024 |