| Jolliffe and Flint Limited | Professional & scientific | 2009 |
| Jollof Eats Ltd | Information & communication | 2025 |
| Jollof Kingdom Ltd | Extraterritorial | 2024 |
| Jolly Allotment Ltd | Manufacturing | 2019 |
| Jolly Hanham Ltd | Hospitality | 2026 |
| Jolly Nice Limited | Hospitality | 2015 |
| Jolly Pattison Limited | Construction | 2017 |
| Jolly Sailor Micropub Limited | Hospitality | 2022 |
| Jomg Properties Limited | Real estate | 2018 |
| Jomi Bar Ltd | Hospitality | 2018 |
| Jomily Limited | Financial services | 2021 |
| Jomm's Limited | Construction | 2014 |
| Jomomedia Limited | Manufacturing | 2023 |
| JON Aitken Ltd | Information & communication | 2022 |
| JON ASH Garden Design Ltd | Professional & scientific | 2014 |
| JON Garrett Consulting Ltd | Information & communication | 2025 |
| JON Hurst Hairdressing Ltd | Other services | 2003 |
| JON James Designs Limited | Information & communication | 2022 |
| JON Line Accountancy Ltd | Professional & scientific | 2021 |
| JON Line Accountants Limited | Professional & scientific | 2013 |
| JON Lloyd Construction Limited | Construction | 2016 |
| JON Pritchard Ltd | Construction | 2006 |
| JON Pritchard Property Management Ltd | Administrative & support | 2014 |
| JON Skipp Ltd | Financial services | 2018 |
| JON Terry Interiors Ltd | Construction | 2010 |
| JON the PON Ltd | Information & communication | 2009 |
| JON Williams - EPR Ltd | Professional & scientific | 2012 |
| Jonathan Cole Productions Limited | Information & communication | 2007 |
| Jonathan James (Holdings) Ltd | Other services | 2014 |
| Jonathan James (Jewellers) Ltd. | Wholesale & retail | 1984 |
| Jonathan Kirk EYE Care Limited | Health & social care | 2025 |
| Jonathan Lear Furniture Ltd | Manufacturing | 2008 |
| Jonathan Lees Architects LLP | | 2010 |
| Jonathan Lees Architecture and Design Ltd | Professional & scientific | 2023 |
| Jonathan Martin Homes Limited | Construction | 2020 |
| Jonathan Michaels Property Services Limited | Construction | 2021 |
| Jonathan Potter Limited | Wholesale & retail | 1976 |
| Jonathan Wick Limited | Professional & scientific | 2023 |
| Jones Electrical Ltd | Construction | 2015 |
| Jones Electrical Services Limited | Construction | 2019 |
| Jones Flat Roofing Limited | Construction | 2023 |
| Jones King Consultants Limited | Administrative & support | 2013 |
| Jones King Partnership Limited | Professional & scientific | 1989 |
| Jonesmillbank Limited | Information & communication | 2011 |
| Jongor (Holdings) Ltd | Financial services | 2015 |
| Jongor Limited | Administrative & support | 1973 |
| Jonny Burton Motion Design Ltd | Information & communication | 2020 |
| Jonny Cochrane Limited | Health & social care | 2013 |
| Jonsen Property Solutions Limited | Real estate | 2023 |
| Jonwen Property Ltd | Real estate | 2019 |
| Jonx Productions Ltd | Education | 2020 |
| Joofa Limited | Health & social care | 2018 |
| Jools Properties Ltd | Real estate | 2015 |
| JOP Management Ltd | Real estate | 2010 |
| Jordan Gilbertson Farriery Ltd | Agriculture & fishing | 2026 |
| Jordan Landscape Design Limited | Construction | 2022 |
| Jordan Leigh Services Ltd | Professional & scientific | 2013 |
| Jordan Sports Limited | Wholesale & retail | 2017 |
| Jorge Rodrigues Ltd | Health & social care | 2014 |
| JOROTRANS46 Ltd | Transport & logistics | 2026 |
| Joryevah Ltd | Other services | 2019 |
| Joseph and Henry Wilson Limited | Professional & scientific | 1895 |
| Joseph Clarkson Hairdressing Ltd | Other services | 2026 |
| Joseph Coles (Developments) Limited | | 1987 |
| Joseph Colman & SON Limited | Construction | 1979 |
| Joseph Estates Limited | Real estate | 2025 |
| Joseph Finch Language Services Limited | Administrative & support | 2019 |
| Joseph Floyd B&I Services Limited | Professional & scientific | 2023 |
| Joseph Griggs and Company Limited | Construction | 1915 |
| Joseph King Interiors Limited | Professional & scientific | 2001 |
| Joseph Meredith Productions Limited | Professional & scientific | 2011 |
| Joseph Passafaro Ltd | Arts & recreation | 2024 |
| Josh Eggleton Consulting Limited | Hospitality | 2015 |
| Josh James Luckett Limited | Extraterritorial | 2024 |
| Josh Leadership Ltd | Professional & scientific | 2023 |
| Josh Wardle Ltd | Professional & scientific | 2025 |
| Joshdg Ltd | Real estate | 2020 |
| Joshiba Corporation Limited | Manufacturing | 2022 |
| Joshua White Design Ltd | Information & communication | 2026 |
| Joska Trans Limited | Transport & logistics | 2018 |
| Joso Properties Ltd | Real estate | 2021 |
| Jouma Talent Solutions Ltd | Administrative & support | 2013 |
| Journease Software Limited | Information & communication | 2006 |
| Journey Care Services Ltd | Health & social care | 2024 |
| Journey Environmental Ltd | Professional & scientific | 2026 |
| Journeying the Globe Ltd | Other services | 2021 |
| Jouw Onderhoud Limited | Financial services | 2022 |
| Jovel Properties Ltd | Real estate | 2024 |
| Jovis Doings Ltd | Information & communication | 2026 |
| Joy & House Ltd | Hospitality | 2024 |
| Joy 1 Limited | Real estate | 2021 |
| Joy Living Limited | Real estate | 2018 |
| Joy Magnet Limited | Arts & recreation | 2018 |
| Joy Placement Services Ltd | Administrative & support | 2019 |
| Joy Property Holdings Limited | Real estate | 2021 |
| Joy Retail Ltd | Other services | 2017 |
| Joy Wonder Limited | Arts & recreation | 2024 |
| Joyful Homes Ltd | Real estate | 2018 |
| Joyful Outcomes Ltd | Professional & scientific | 2024 |
| Joyful Transformation Ltd | Other services | 2024 |