| Jocelyn Richards Therapies Ltd | Health & social care | 2025 |
| Jodies SG Limited | Professional & scientific | 2021 |
| JOE Brady Software Limited | Professional & scientific | 2024 |
| JOE Dovey Civil Engineering Ltd | Construction | 2012 |
| JOE Gaster Ltd | Information & communication | 2014 |
| Joey Does Tech Ltd | Information & communication | 2023 |
| Johan (South) Limited | Professional & scientific | 1997 |
| John Charcol Mortgages Limited | Financial services | 2006 |
| John Chris Ltd | Transport & logistics | 2020 |
| John Clean Limited | Construction | 2022 |
| John Gary Easlick Ltd | Extraterritorial | 2024 |
| John Heawood Consulting Limited | Professional & scientific | 2014 |
| John Henry King Fund Limited | Other services | 1969 |
| John Hubbard Limited | Construction | 2022 |
| John I'Anson Construction Ltd | Construction | 2020 |
| John Law Transport Limited | Extraterritorial | 1992 |
| John Lewis Consulting Limited | Professional & scientific | 2010 |
| John Parker Limited | Agriculture & fishing | 1990 |
| John Reid Locums Ltd | Health & social care | 2019 |
| John Ronald England Ltd | Extraterritorial | 2025 |
| John Tavender Wealth Management Limited | Financial services | 2018 |
| John Taylor Motorsport Ltd. | Wholesale & retail | 2004 |
| John Willment Marine Limited | Professional & scientific | 1961 |
| Johnny's Transport Ltd | Transport & logistics | 2025 |
| Johnsen Property Investments Limited | Real estate | 2022 |
| Johnson Ward Developments Limited | Construction | 2024 |
| Johnstone Technical Services Limited | Professional & scientific | 2007 |
| Joiners Expertise Ltd | Manufacturing | 2025 |
| Joiners Forever Limited | Hospitality | 2024 |
| Joiners Forever Soton C.I.C. | Arts & recreation | 2025 |
| Joiners Live Music Limited | Arts & recreation | 2024 |
| Joiners Music Limited | Professional & scientific | 2014 |
| Joining Shackle Limited | Administrative & support | 2008 |
| Joint Investment Ltd | Real estate | 2025 |
| Jojo F Music Limited | Information & communication | 2019 |
| JOL Properties Limited | Real estate | 2023 |
| Jolene Jolene Ltd | Wholesale & retail | 2015 |
| Jollie Trading Ltd | Hospitality | 2026 |
| Jolly Investments Ltd | Real estate | 2024 |
| Jolly Property Management Ltd | Real estate | 2024 |
| Jolly Roger Sailing Limited | Education | 2016 |
| Joma (Hampshire) Limited | Manufacturing | 2012 |
| Joma Estates Limited | Real estate | 2019 |
| JON Adley Investments Limited | Financial services | 2017 |
| JON Banfield Photography Limited | Professional & scientific | 2005 |
| JON Maynard Boundaries Ltd | Professional & scientific | 2003 |
| Jonathan Clark Physiotherapy Ltd | Health & social care | 2014 |
| Jonathan Rees Property Ltd | Real estate | 2022 |
| Jonathan Shaw Company Ltd. | Real estate | 2017 |
| Jonathan Terry Independent Funeral Directors Ltd | Other services | 2016 |
| Jones Estates and Lettings Ltd | Real estate | 2023 |
| Jones Risk Consultancy Ltd | Professional & scientific | 2021 |
| Jonlink Limited | Wholesale & retail | 1976 |
| Joost Engines Ltd | Manufacturing | 2013 |
| Jopas Transport Ltd | Transport & logistics | 2022 |
| Jordan Provident Limited | Administrative & support | 2007 |
| Jorwick Data Limited | Information & communication | 2025 |
| Josben Accountancy Limited | Professional & scientific | 2017 |
| Josben Care Services Limited | Health & social care | 2015 |
| Josema Ltd | Transport & logistics | 2025 |
| Joseph Oguntayo Limited | Hospitality | 2024 |
| Josh Stevens Paving and Landscapes Ltd | Administrative & support | 2018 |
| Joshua L Twine Ltd | Professional & scientific | 2021 |
| Joshua One Seven UK Ltd | Manufacturing | 2021 |
| Joshua Zimmermann Ltd | Wholesale & retail | 2025 |
| Josie's Chandler's Ford Limited | Hospitality | 2022 |
| Josie's Romsey Limited | Hospitality | 2019 |
| Josie's Wickham Ltd | Hospitality | 2025 |
| Josw Consulting Ltd | Professional & scientific | 2026 |
| Jour Technologies Limited | Information & communication | 2025 |
| Journey Building Contractors Limited | Construction | 2016 |
| Journey Estates Limited | Construction | 2021 |
| Journey Spark Adventures Ltd | Administrative & support | 2026 |
| Journeying | Administrative & support | 2009 |
| Joviza Ltd | Real estate | 2019 |
| JOW Scaffolding Services Ltd | Construction | 2020 |
| Joy Digital Ltd | Wholesale & retail | 2024 |
| Joy Plumbing Limited | Construction | 2008 |
| Joybloom Ltd | Hospitality | 2024 |
| Joyd Kitchen Limited | Hospitality | 2023 |
| Joyhivee Ltd | Information & communication | 2025 |
| Joyspring Vitamins Ltd | Wholesale & retail | 2026 |
| Jozef Z Ltd | Transport & logistics | 2015 |
| JP & Co Accountants Limited | Professional & scientific | 2022 |
| JP & Co Investments Limited | Financial services | 2026 |
| JP Appliances Ltd. | Wholesale & retail | 2014 |
| JP Consulting and Adjusting Limited | Administrative & support | 2020 |
| JP Elite Properties Ltd | Real estate | 2025 |
| JP Facial Aesthetics Limited | Financial services | 2014 |
| JP Group Enterprises Limited | Financial services | 2020 |
| JP Investments Hants Ltd | Real estate | 2019 |
| JP Plumbing & Heating Consultants Limited | Construction | 2005 |
| JP Projects Ltd | Real estate | 2022 |
| JPC Homes Ltd | Real estate | 2018 |
| JPD Investments Ltd | Hospitality | 2019 |
| JPG Welding Limited | Manufacturing | 2024 |
| JPH Driver Solutions Limited | Education | 2019 |
| JPH Engineering Ltd | Construction | 2021 |
| Jphcm Limited | Health & social care | 2020 |
| Jpink Marketing Ltd | Professional & scientific | 2019 |