| Jamus Limited | Extraterritorial | 2013 |
| Jamyah Ltd | Manufacturing | 2024 |
| Janacouriers Ltd | Transport & logistics | 2025 |
| Janan (Stratford) Limited | Wholesale & retail | 2022 |
| Janan Holdings Limited | Financial services | 2022 |
| Janan Leicester Limited | Wholesale & retail | 2025 |
| Janan Limited | Wholesale & retail | 2011 |
| Janan Online Limited | Administrative & support | 2014 |
| Janatech Ltd | Wholesale & retail | 2025 |
| Janaza Announcements | Other services | 2023 |
| Jangir Estates Limited | Real estate | 2021 |
| Jangled PUB Co Ltd | Hospitality | 2014 |
| Jannat Store Ltd | Wholesale & retail | 2025 |
| Janny Media Limited | Professional & scientific | 2026 |
| Janom Limited | Hospitality | 2018 |
| Janrick Intl Ltd | Wholesale & retail | 2014 |
| Janrick Maintenance Services Ltd | Construction | 2021 |
| Jansons Direct Linens Limited | Wholesale & retail | 2005 |
| Jant Holdings Limited | Real estate | 2025 |
| Janus Architecture Limited | Professional & scientific | 2021 |
| Janus Building Design Ltd | Professional & scientific | 2000 |
| Janus Capital Management Ltd | Financial services | 2018 |
| Janusian Limited | Professional & scientific | 2018 |
| JAP Car Finder Limited | Wholesale & retail | 2017 |
| Japanese Headspa Bradford Ltd | Extraterritorial | 2024 |
| Japanese Specialist Cars Limited | Wholesale & retail | 2025 |
| JAR Property Maintenance Ltd | Other services | 2016 |
| Jardonich Engineering Limited | Construction | 2000 |
| Jarfort Ltd. | Wholesale & retail | 1989 |
| JAS Athwal Ltd | Professional & scientific | 2023 |
| Jasim Tahir Ltd | Wholesale & retail | 2026 |
| Jasmine Jewellery BFD Ltd | Wholesale & retail | 2025 |
| Jasmine Jewellery Ltd | Wholesale & retail | 2023 |
| Jasmine Properties (Bradford) Limited | Real estate | 2021 |
| Jasnova Ltd | Wholesale & retail | 2025 |
| Jason Easton Plastering Limited | Construction | 2008 |
| Jassam Capital Ltd | Real estate | 2022 |
| Jatala Limited | Wholesale & retail | 2022 |
| Jatinder.It Limited | Professional & scientific | 2016 |
| JATKINSONENP73 Ltd | Health & social care | 2015 |
| Jatlan Limited | Hospitality | 2025 |
| Java Village (HX) Ltd | Hospitality | 2016 |
| Javaid and Khan Limited | Health & social care | 2012 |
| Javed Halal Meat & Grocery Ltd | Wholesale & retail | 2026 |
| Jawed Investments Limited | Financial services | 2024 |
| Jaworski Software Solutions Ltd | Information & communication | 2024 |
| JAY GAS Specialist Limited | Professional & scientific | 2026 |
| JAY Griffith Electrical Ltd | Construction | 2021 |
| Jaycyn Limited | Transport & logistics | 2025 |
| Jayhari Vishnu Limited | Wholesale & retail | 2003 |
| Jayne Taylor Aesthetics Limited | Health & social care | 2017 |
| Jaynelea Construction (PHASE3 Sowerby Bridge) Limited | Construction | 2024 |
| Jaynelea Construction (Queensbury) Limited | Construction | 2020 |
| Jaynelea Construction (Sowerby Bridge) Limited | Construction | 2020 |
| Jaynelea Construction Limited | Construction | 2017 |
| Jayrock Juices Ltd | Hospitality | 2022 |
| Jays Prop Shop Ltd | Construction | 2023 |
| Jayvira Ltd | Wholesale & retail | 2025 |
| Jazz Squared Limited | Financial services | 2022 |
| JB - Waste Clean Ltd | Water & waste | 2025 |
| JB a Services Ltd | Transport & logistics | 2024 |
| JB Air Conditioning Limited | Construction | 2023 |
| JB and DP Trading Ltd | Wholesale & retail | 2022 |
| JB Cleaning Supplies and Hire Ltd | Administrative & support | 2024 |
| JB Driveways and Landscaping Ltd | Administrative & support | 2022 |
| JB Installs Ltd | Extraterritorial | 2019 |
| JB Metals National Limited | Wholesale & retail | 2025 |
| JB Properties (West Yorkshire) Limited | Real estate | 2020 |
| JB Service PVT Ltd | Other services | 2019 |
| JB Surfacing Ltd | Construction | 2019 |
| JB63 Limited | Construction | 2019 |
| JB7 Business and Corporate Services Limited | Professional & scientific | 2018 |
| Jbailey Logistics Ltd | Transport & logistics | 2026 |
| JBF MMA Gym Ltd | Arts & recreation | 2024 |
| JBP Plumbing & Saniflo Engineers Limited | Construction | 2023 |
| JBS Delivery’S Ltd | Transport & logistics | 2025 |
| JBZ Peels Estates Ltd | Real estate | 2022 |
| JC Elite Property Services Ltd | Real estate | 2024 |
| JC Farm Services Ltd | Agriculture & fishing | 2024 |
| JC Solutions (North) Ltd | Professional & scientific | 2023 |
| JC Trade Supplies Ltd | Wholesale & retail | 2020 |
| Jc-Mpharm Ltd | Wholesale & retail | 2022 |
| JCB Residential Ltd | Real estate | 2024 |
| JCB Waste Ltd | Water & waste | 2025 |
| JCC & Co Holdings Limited | Financial services | 2018 |
| JCF Developments (Yorkshire) Ltd | Energy | 2024 |
| Jcgroup@Jcgroup Limited | Administrative & support | 2022 |
| JCH Properties (Yorkshire) Limited | Real estate | 2021 |
| JCL Agricultural & Plant Services Limited | Wholesale & retail | 2022 |
| JCL Machinery Limited | Manufacturing | 2013 |
| JCL VIC Ltd | Hospitality | 2023 |
| JCP Group Bradford Ltd | Wholesale & retail | 2025 |
| JCP Services Energy Ltd | Construction | 2021 |
| JCR Distributions Ltd | Wholesale & retail | 2026 |
| JCS Welding Services Ltd | Construction | 2023 |
| JCT600 (Audi) Limited | Extraterritorial | 1938 |
| JCT600 (Audi/Vw) Limited | Extraterritorial | 2002 |
| JCT600 (EBT Trustees) Limited | Extraterritorial | 2008 |
| JCT600 (Lincoln) Limited | Extraterritorial | 2008 |
| JCT600 (Lincolnshire) Limited | Extraterritorial | 2003 |