| Jetgreen Ltd | Transport & logistics | 2018 |
| Jeto Trading Ltd | Other services | 2015 |
| Jett Management Ltd | Hospitality | 2024 |
| Jewelwork Limited | Wholesale & retail | 2011 |
| JFD Project Solutions Limited | Professional & scientific | 2014 |
| JH Veterinary Services Ltd | Professional & scientific | 2019 |
| Jientdworf LLP | | 2014 |
| Jillion Limited | Real estate | 2020 |
| JJ Chichester Limited | Hospitality | 2025 |
| JJ Plumbing Services Ltd | Construction | 2023 |
| JJ Technical Services Limited | Professional & scientific | 2009 |
| JJA Commerce Ltd | Wholesale & retail | 2025 |
| JJW2011 Ltd | Real estate | 2011 |
| JKN Property Holdings Ltd | Real estate | 2025 |
| JL Holdings Europe Ltd | Financial services | 2020 |
| JLA Joinery Ltd | Manufacturing | 2016 |
| Jlaker Home Improvements Ltd | Construction | 2024 |
| JLB Brickwork Limited | Construction | 2019 |
| JLB Plumbing and Heating Limited | Construction | 2018 |
| JLC Resolve Limited | Professional & scientific | 2024 |
| JLH Property Investments Limited | Real estate | 2024 |
| JLS 715 Limited | Arts & recreation | 2024 |
| JLS IT Consultants Ltd | Information & communication | 2014 |
| Jmbe Partners Ltd | Health & social care | 2012 |
| JMC Resolutions Limited | Administrative & support | 2025 |
| JMS Yachting Limited | Financial services | 2021 |
| Jmusic Ltd | Information & communication | 2000 |
| JNM Property Ltd | Real estate | 2024 |
| JNS Global Consultants Limited | Administrative & support | 2011 |
| Jobs With NO Borders Ltd | Information & communication | 2019 |
| John Booth Engineering Limited | Professional & scientific | 1999 |
| John Brown Architecture Limited | Professional & scientific | 1999 |
| John Clayton & Associates (Leisure Developments) Limited | Professional & scientific | 2002 |
| John Gibbons Bodymaster Method Limited | Extraterritorial | 2013 |
| John Mccormack Pension Ltd | Administrative & support | 2024 |
| John Mills (Consultancy) Limited | Professional & scientific | 2006 |
| John Peall Plumbing & Bathrooms Ltd | Construction | 2024 |
| John Pearson Sheds & Fencing Ltd | Manufacturing | 2013 |
| John Tabb Plastering Ltd | Construction | 2023 |
| John Turner Phormiums Limited | Real estate | 2003 |
| John Virgo Entertainment Ltd | Arts & recreation | 2002 |
| Johnson M & E Group Ltd | Construction | 2011 |
| Johnson's Decorating Services Limited | Construction | 2019 |
| Johnston Estates Limited | Real estate | 2013 |
| Jokertoons Ltd | Arts & recreation | 2020 |
| Jome Branding and Creative Ltd | Professional & scientific | 2026 |
| JON Stinton Design Ltd | Professional & scientific | 2022 |
| Jonathan Willcocks Limited | Arts & recreation | 1998 |
| Jons Developments Limited | Real estate | 1958 |
| Jordan Construction Services Ltd | Construction | 2018 |
| Joseph James Construction Ltd | Construction | 2022 |
| Jowick Limited | Information & communication | 2011 |
| Joy Architects Ltd | Professional & scientific | 2018 |
| Joyful Jellybean Ltd | Wholesale & retail | 2023 |
| JP Application Development Ltd | Information & communication | 2015 |
| JP Body Repairs Limited | Wholesale & retail | 2003 |
| Jpls Canvas Ltd | Wholesale & retail | 2023 |
| JPM Advanced Solutions Ltd | Construction | 2024 |
| JPM Recruitment Agency Limited | Health & social care | 1988 |
| JPW Carpentry & Building Ltd | Construction | 2026 |
| JR Landscapes & Groundworks Ltd | Construction | 2021 |
| JRB Golf Limited | Wholesale & retail | 2008 |
| JRM Auto Technics Ltd | Wholesale & retail | 2026 |
| JRP Distribution Limited | Wholesale & retail | 2001 |
| JRS Adept Composites Ltd | Wholesale & retail | 2024 |
| JS Air Curtains Limited | Wholesale & retail | 2024 |
| JSP Rentals Limited | Real estate | 2025 |
| JSS (Hampshire) Limited | Professional & scientific | 2002 |
| JSS (South Coast) Limited | Real estate | 2010 |
| Jssf Limited | Hospitality | 2024 |
| Jstone Distribution Ltd | Wholesale & retail | 2026 |
| JT Chichester Limited | Wholesale & retail | 2022 |
| JT Joinery & Bespoke Interiors Ltd | Construction | 2025 |
| JT Winchester Limited | Wholesale & retail | 2022 |
| JTH Interiors Limited | Wholesale & retail | 2019 |
| Jubilee Mews Management Limited | Households | 2013 |
| Jubilee Products Ltd | Wholesale & retail | 2019 |
| Juice World Limited | Wholesale & retail | 1996 |
| Julian Roberts Consulting Ltd | Professional & scientific | 2017 |
| Julius Lumsden Ltd | Manufacturing | 2024 |
| Jull Gourmet 2 Ltd | Hospitality | 2023 |
| Jull Gourmet 3 Ltd | Hospitality | 2023 |
| Jull Gourmet Ltd | Hospitality | 2023 |
| Jumping Curves Limited | Real estate | 2022 |
| Jumping Jacks Entertainments Limited | Arts & recreation | 2015 |
| Juna Marketing Limited | Professional & scientific | 2011 |
| Juniper Leisure Limited | Arts & recreation | 2004 |
| Juno Independent Mortgages Ltd | Financial services | 2006 |
| Jupiter Energy Limited | Administrative & support | 2006 |
| Just Aggregate (Sussex) Limited | Construction | 2019 |
| Just Drinking Water Ltd | Manufacturing | 2006 |
| Just Plane Sailing Ltd | Arts & recreation | 2022 |
| JVC Mayles Ltd | Real estate | 2023 |
| JW Research Limited | Professional & scientific | 2013 |
| JW Trustee Services Limited | Financial services | 2015 |
| JWA Plant Hire Ltd | Administrative & support | 2025 |
| JWL Installs Ltd | Construction | 2011 |
| JWT Estates Limited | Real estate | 1998 |
| K L CAS Limited | Professional & scientific | 2014 |
| K N Spice Limited | Hospitality | 2024 |