| Jimmy Bullard Limited | Administrative & support | 2006 |
| Jimmy's Jibs Ltd | Information & communication | 2019 |
| JJ Kingcome Ltd | Hospitality | 2017 |
| JJE Holdings Ltd | Real estate | 2021 |
| JK Investment Management LLP | | 2003 |
| JK Investment Management Services Limited | Financial services | 2003 |
| JK London News Limited | Wholesale & retail | 2022 |
| JK Wilson Design Ltd | Professional & scientific | 2016 |
| JKCARE84 Ltd | Health & social care | 2025 |
| JKT Solutions Limited | Professional & scientific | 2015 |
| Jkthornycroft Ltd | Real estate | 2021 |
| JL Garden Services Limited | Administrative & support | 2022 |
| JLH Security Limited | Administrative & support | 2022 |
| JLL Limited | Administrative & support | 2025 |
| Jlpd Holdings Limited | Financial services | 2025 |
| JM Rides Limited | Manufacturing | 2018 |
| JMF Consulting Limited | Information & communication | 2014 |
| JMH Contracts Ltd | Construction | 2019 |
| JMJ Garages (Southern) Limited | Wholesale & retail | 1972 |
| JMW Advisory Limited | Professional & scientific | 2025 |
| Jnjk Holding Ltd | Administrative & support | 2024 |
| JO Lane Consulting Limited | Professional & scientific | 2023 |
| Joan Parnell Ltd | Health & social care | 2019 |
| JOB IS Done Ltd | Other services | 2025 |
| Jobell Cleaning Services Ltd | Administrative & support | 2019 |
| Jobl Services Ltd | Administrative & support | 2022 |
| Joel Benton Consulting Limited | Professional & scientific | 2014 |
| John Goater Limited | Construction | 2006 |
| John Gosden Consulting Ltd | Professional & scientific | 2013 |
| John Kennedy (Surrey) Limited | Extraterritorial | 2013 |
| John Mowlem & Co. Ltd | Construction | 2018 |
| John Mowlem & Company Limited | Construction | 2018 |
| John Poulten (Holdings) Limited | Construction | 1952 |
| John Poulten Limited | Professional & scientific | 1999 |
| John Rennie Consulting Limited | Information & communication | 2025 |
| John Russell Management Limited | Real estate | 2003 |
| Johnny Shake Limited | Hospitality | 2015 |
| Johnroop Limited | Professional & scientific | 2022 |
| Johnson & Skinner Building Contractors Limited | Construction | 2002 |
| Johnson Fellowes Limited | Professional & scientific | 1988 |
| Johnson Tree Services Ltd. | Administrative & support | 2018 |
| Johnston Accountants Limited | Professional & scientific | 2014 |
| Jojo Cooper Ltd | Professional & scientific | 2022 |
| Jolas Events Ltd | Arts & recreation | 2022 |
| JON Arnold Holdings Limited | Professional & scientific | 2006 |
| JON Arnold Images Limited | Professional & scientific | 2006 |
| Jonathan Parker Consulting Limited | Professional & scientific | 2015 |
| Jones Bamber Productions Limited | Information & communication | 2011 |
| Jones French Jones Limited | Information & communication | 2014 |
| Jonesey Ltd | Arts & recreation | 2019 |
| Jonny-Jibs Limited | Information & communication | 2007 |
| Jordan Essex Limited | Health & social care | 2014 |
| Joseb Property Limited | Real estate | 2026 |
| Joseph Stone Design Ltd | Professional & scientific | 2019 |
| Jotec UK Ltd | Wholesale & retail | 2006 |
| Journeys J&C Limited | Wholesale & retail | 2022 |
| Joy EAT Takeaway Ltd | Hospitality | 2024 |
| JP ENG Ltd | Information & communication | 2010 |
| Jphs Ventures Ltd | Information & communication | 2026 |
| JRB Inns Limited | Real estate | 2009 |
| JRP Developments Ltd | Information & communication | 2017 |
| Jrrl Medical Services Ltd | Administrative & support | 2023 |
| JS (West Surrey) Limited | Real estate | 2020 |
| JS Guildford Ltd | Administrative & support | 2024 |
| JS Karatefit Limited | Other services | 2023 |
| JSK Capital Advisors Ltd | Financial services | 2014 |
| JSR Energy Limited | Energy | 2012 |
| Jtfm Limited | Extraterritorial | 2024 |
| Jubilee Nashe Limited | Wholesale & retail | 2019 |
| Jubilee Property Development Ltd | Construction | 2014 |
| Judd Legal Limited | Professional & scientific | 2025 |
| Judeglen Limited | Real estate | 1981 |
| Julets BOY Ltd | Wholesale & retail | 2024 |
| Julia Lampard Ltd | Wholesale & retail | 2009 |
| Julia Taylor Occupational Therapy Ltd | Health & social care | 2024 |
| Julie Kaya Interior Design Limited | Professional & scientific | 2016 |
| Juliet & Foxtrot Ltd | Information & communication | 2016 |
| Julius Holdings Limited | Professional & scientific | 2018 |
| Jumpship Limited | Information & communication | 2017 |
| Juni Holdings Limited | Financial services | 2023 |
| Junior Playmakers Limited | Arts & recreation | 2012 |
| Juno TV Limited | Information & communication | 2026 |
| Jupiter Education Ltd | Education | 2026 |
| JUS: In-House Legal Services Limited | Professional & scientific | 2016 |
| Just Audio Limited | Information & communication | 2015 |
| Just Beauty Guildford Ltd | Other services | 2023 |
| Just Employment Holdings Limited | Financial services | 2024 |
| Just Employment Limited | Professional & scientific | 1998 |
| Just Facades.Com Ltd | Professional & scientific | 2009 |
| Justaclick Limited | Hospitality | 2020 |
| Justclickgo Limited | Information & communication | 2023 |
| Justpos Technologies UK Ltd | Information & communication | 2018 |
| JV Nails & Beauty Ltd | Other services | 2021 |
| JW Pilates Farnham Limited | Arts & recreation | 2017 |
| JW Pilates Ltd | Arts & recreation | 2020 |
| JWC IT Services Ltd | Information & communication | 2016 |
| Jwih Limited | Real estate | 2024 |
| Jwms Marketing Advisor Limited | Education | 2023 |
| K & H Construction Services Ltd | Construction | 2016 |
| K Aquila Limited | Health & social care | 2017 |