| JJE Eboesomi Healthcare Limited | Health & social care | 2023 |
| Jjen Properties Limited | Real estate | 2026 |
| Jjig Limited | Real estate | 2016 |
| JJJ Autos Ltd | Wholesale & retail | 2026 |
| JJL Media Limited | Information & communication | 2021 |
| JK (NW) Ltd | Health & social care | 2025 |
| JK Atwal Properties Ltd | Real estate | 2024 |
| JK Financial Solutions Yorkshire Limited | Financial services | 2019 |
| JK Safety Solutions Ltd | Professional & scientific | 2021 |
| JKC800 Ltd | Wholesale & retail | 2023 |
| Jkglobe Ltd | Information & communication | 2025 |
| JKM Holdings Limited | Construction | 1996 |
| Jkred Holdings Ltd | Professional & scientific | 2025 |
| JLA Performance Ltd | Wholesale & retail | 2024 |
| JLB Maintenance Limited | Other services | 2018 |
| JLF Property Services Ltd | Real estate | 2026 |
| Jlfproperties & Developments Limited | Real estate | 2025 |
| Jlmk Global Limited | Wholesale & retail | 2020 |
| JLR HAY Supplies Limited | Agriculture & fishing | 2025 |
| Jlrq Properties Ltd | Real estate | 2025 |
| Jlzw Ltd | Wholesale & retail | 2024 |
| JM2BART Ltd | Health & social care | 2023 |
| JMA Accounting Solutions Ltd | Professional & scientific | 2014 |
| JMA Ceramics Limited | Construction | 2021 |
| JMA Fibre Ltd | Information & communication | 2023 |
| JMA Managed Accounts Ltd | Professional & scientific | 2015 |
| JMA Payroll & DP Support Services Ltd | Professional & scientific | 2013 |
| JMB Corporate Law Limited | Professional & scientific | 2023 |
| JMC Development Group Limited | Real estate | 2020 |
| JMC Electrical Solutions Ltd | Construction | 2019 |
| Jmcc Accounting Ltd | Professional & scientific | 2024 |
| JMD Food Solutions Ltd | Wholesale & retail | 2025 |
| JMD Product Solutions Limited | Wholesale & retail | 2025 |
| JME Developments (Holmfirth) Ltd | Construction | 2010 |
| JME Engineering Ltd | Manufacturing | 2014 |
| JMF Maintenance Services Ltd | Construction | 2023 |
| JMH Installations Limited | Construction | 2024 |
| JMI Marketing Management Limited | Professional & scientific | 2017 |
| JN Cooper & Partners Ltd | Professional & scientific | 2012 |
| JNC Coaching Ltd | Education | 2025 |
| JNC Property Acquisitions Ltd | Real estate | 2023 |
| JNC Property Development Ltd | Construction | 2025 |
| JNC Property Investments Ltd | Real estate | 2026 |
| JNC Property Ventures Ltd | Construction | 2025 |
| JNH Consultants Limited | Professional & scientific | 2011 |
| JNT Destinations Ltd | Administrative & support | 2015 |
| JO Oakland Creative Consultant Limited | Professional & scientific | 2007 |
| JOA Roofing Ltd | Construction | 2026 |
| Joanna Keely Flower School Ltd | Education | 2018 |
| Joanna Keely Flowers Ltd | Wholesale & retail | 2018 |
| JOB Brown Consultancy Ltd | Information & communication | 2018 |
| JOB Routes UK Limited | Extraterritorial | 2021 |
| Jobeck Properties Limited | Real estate | 2013 |
| Jobsglob.Com Limited | Administrative & support | 2023 |
| JOE Bottomley Ventures Limited | Construction | 2022 |
| JOE Gratino Builders Ltd | Construction | 2015 |
| Joe's Car Cleaning Service Ltd | Administrative & support | 2026 |
| Joe's Car Transporting Service Ltd | Transport & logistics | 2026 |
| Joel's Recycling Limited | Water & waste | 2021 |
| Joey’S Pet Boutique Ltd | Wholesale & retail | 2024 |
| Joe’S Bites Ltd | Hospitality | 2026 |
| Jofa Cleaning Services Ltd | Administrative & support | 2023 |
| John Beaumont Plumbers & Electricians Limited | Construction | 2005 |
| John Berry Limited | Hospitality | 2023 |
| John Cavendish Limited | Manufacturing | 1988 |
| John Corby Limited | Administrative & support | 2009 |
| John Crowther and Sons (Milnsbridge) Limited | Professional & scientific | 1989 |
| John Donaldson Services Limited | Professional & scientific | 2015 |
| John Fredericks Aluminium Ltd | Manufacturing | 2021 |
| John Fredericks Group Limited | Extraterritorial | 2026 |
| John Fredericks Plastics Group Limited | Financial services | 2021 |
| John Fredericks Plastics Limited | Manufacturing | 2001 |
| John G. Hardy Limited | Extraterritorial | 2008 |
| John Horsfall & Sons Limited | Wholesale & retail | 2004 |
| John Horsfall & Sons(Greetland),Limited | Real estate | 1905 |
| John Horsfall (Properties) Ltd | Real estate | 2014 |
| John Horsfall Properties (Holdings) Ltd | Real estate | 2021 |
| John L Brierley Property Ltd | Real estate | 2025 |
| John L Brierley Textiles Ltd | Wholesale & retail | 2018 |
| John M Thornton Limited | Professional & scientific | 2011 |
| John Oxley Limited | Real estate | 2003 |
| John P. Sparling Limited | | 1972 |
| John Platt Wealth Management Ltd | Financial services | 2022 |
| John Radcliffe & Sons (1802) Limited | Real estate | 1918 |
| John Radcliffe & Sons Ltd | Construction | 2009 |
| John Radcliffe and Sons (Holdings) Ltd | Real estate | 2013 |
| John Radcliffe Investments Limited | Real estate | 2004 |
| John Radcliffe Plant Hire Ltd | Administrative & support | 2015 |
| John Shaw & SON (Hauliers) Limited | Wholesale & retail | 1958 |
| John William News (Yorkshire) Ltd | Wholesale & retail | 2017 |
| John William News Limited | Wholesale & retail | 2024 |
| John Woodhead (Dobroyd Mills) Limited | Real estate | 1982 |
| John Woodhead Developments Limited | Real estate | 2003 |
| Johnson & Saunders Ltd | Professional & scientific | 2014 |
| Johnsons Wellfield Ltd | Mining & quarrying | 1943 |
| Johnstone & Dargue Limited | Construction | 2018 |
| Johnstone Creative Management Ltd | Professional & scientific | 2025 |
| Jolaby Limited | Manufacturing | 2008 |
| Jolly Goods Direct Ltd | Wholesale & retail | 2023 |
| Jomox Limited | Other services | 2018 |