| Jonas Financial Limited | Professional & scientific | 2011 |
| Jonas Financial Services Ltd | Professional & scientific | 2025 |
| Jonas Woodhead & Sons (Leeds) Limited | | 1958 |
| Jonathan & Ruth Cooke Limited | Professional & scientific | 2002 |
| Jonathan Bean Design Limited | Arts & recreation | 1988 |
| Jonathan Cape Dental Surgeon Limited | Health & social care | 2010 |
| Jonathan Dawson Car Sales Ltd | Wholesale & retail | 2005 |
| Jonathan Isaacs Limited | Professional & scientific | 2025 |
| Jonathan James Building Solutions Ltd | Construction | 2023 |
| Jonathan Macgregor Art Ltd | Professional & scientific | 2016 |
| Jonathan Marcus Limited | Administrative & support | 2025 |
| Jonathan Ross Ltd | Administrative & support | 2015 |
| Jonathan S White Limited | Professional & scientific | 1998 |
| Jonathan Sager Ltd | Health & social care | 2022 |
| Jonathan Stoner Holdings Limited | Wholesale & retail | 2008 |
| Jonathan Straight Limited | Information & communication | 2014 |
| Jonathon David Ltd | Wholesale & retail | 2020 |
| Jones (J27) Accountants Ltd | Professional & scientific | 2022 |
| Jones Bar Group Limited | Professional & scientific | 2008 |
| Jones Bishop Limited | Real estate | 2017 |
| Jones Bishop Property Holdings Ltd | Real estate | 2026 |
| Jones Business Services Limited | Professional & scientific | 2006 |
| Jones Construction Limited | Construction | 1993 |
| Jones Housing Ltd | Real estate | 2021 |
| Jones Joint Solutions Limited | Health & social care | 2021 |
| Jones Management Solutions Ltd | Professional & scientific | 1994 |
| Jones Mcgowan Ltd | Professional & scientific | 2012 |
| Jones Myers Ltd | Professional & scientific | 2014 |
| Jones Williams (Nottingham) Ltd | Construction | 2018 |
| Joni Developments Limited | Real estate | 2018 |
| Jonny Grayshon Ltd | Arts & recreation | 2023 |
| Jonny Mcpherson Limited | Arts & recreation | 2020 |
| Jonny Packham Design Ltd | Information & communication | 2024 |
| Jonobrand Group Ltd | Professional & scientific | 2024 |
| Jontom Ltd | Wholesale & retail | 2020 |
| Jooce Ltd | Wholesale & retail | 1994 |
| Joof Investments Limited | Professional & scientific | 2014 |
| Joom LLP | | 2016 |
| Jopafa Electronics Ltd | Wholesale & retail | 2023 |
| Joppers SHF Ltd | Information & communication | 2011 |
| JOR Clinical Safety Ltd | Professional & scientific | 2023 |
| JOR Signs Limited | Construction | 2026 |
| JORAVAR6 Holdings Ltd | Financial services | 2023 |
| JORAVAR6 Properties Ltd | Real estate | 2023 |
| Jordan Bikes Ltd | Wholesale & retail | 2003 |
| Jordan Gilroy Ltd | Professional & scientific | 2017 |
| Jordan Jude Harrison Ltd | Professional & scientific | 2021 |
| Jordan Lane Consulting Limited | Professional & scientific | 2017 |
| Jordan Upholstery Ltd | Manufacturing | 2018 |
| Jordandrops Ltd | Transport & logistics | 2026 |
| Jorgold Ltd | Wholesale & retail | 2018 |
| Jorja Belle Limited | Real estate | 2018 |
| Jorko Childcare Ltd | Health & social care | 2025 |
| Jorland Sporting Academy CIC | Arts & recreation | 2023 |
| Jorrd Limited | Manufacturing | 2025 |
| Jorvik Holdings Ltd | Financial services | 2024 |
| Jorvik Ltd | Real estate | 2024 |
| Jorvik Properties Limited | Households | 1981 |
| Jorvik Safety Netting Ltd | Construction | 2016 |
| Josef Fish Bar Ltd | Hospitality | 2025 |
| Joseph Andrew Limited | Manufacturing | 2017 |
| Joseph Brian Electrical Ltd | Construction | 2023 |
| Joseph Cornerstone Ltd | Extraterritorial | 2024 |
| Joseph Firth Limited | Wholesale & retail | 2008 |
| Joseph Geldart & Sons Ltd | Other services | 2012 |
| Joseph Krasinski Consultancy Ltd | Professional & scientific | 2023 |
| Joseph MAY & Sons (Leeds) Limited | Professional & scientific | 1965 |
| Joseph Moore(Coal)Limited | Real estate | 1930 |
| Joseph Newsome (Holdings) Limited | | 1955 |
| Joseph Pickering & Sons Limited | Manufacturing | 1900 |
| Joseph Sellers & SON Limited | Manufacturing | 1937 |
| Josephine Kalonda Ltd | Health & social care | 2015 |
| Josephkariega Limited | Health & social care | 2023 |
| Josephs Accounting Services Limited | Administrative & support | 2002 |
| Josh Shop Limited | Wholesale & retail | 2025 |
| Joshcurtis-Productions. Ltd | Information & communication | 2026 |
| Joshdan Limited | Administrative & support | 2009 |
| Joshua Daniel Delivery Limited | Other services | 2025 |
| Joshua Howard Joinery Limited | Construction | 2026 |
| Joshua Hoyle & Sons Limited | Extraterritorial | 1873 |
| Joshua James Ventures Limited | Wholesale & retail | 2016 |
| Joshua Mcbride Limited | Wholesale & retail | 2019 |
| Joshua Thomas and Partners Ltd | Professional & scientific | 2006 |
| Joshua’S Shop Limited | Wholesale & retail | 2025 |
| Joto Ltd | Professional & scientific | 2024 |
| Jottar Limited | Professional & scientific | 2014 |
| Jotti Carpets & Furnishing Ltd | Wholesale & retail | 2025 |
| Journal Limited | Professional & scientific | 2013 |
| Journey Business Group Limited | Professional & scientific | 2022 |
| Journey East Limited | Administrative & support | 2006 |
| Journey's Holidays Ltd | Transport & logistics | 2022 |
| Journeymen Games Ltd | Information & communication | 2026 |
| Jowett Kennedy Fidler LLP | | 2019 |
| Jowitt Contractors Ltd | Construction | 2006 |
| Joy Junction Ltd | Professional & scientific | 2024 |
| Joyccare Limited | Health & social care | 2022 |
| Joyce Brandt Care Ltd | Health & social care | 2019 |
| Joyce Property Group Ltd | Real estate | 2024 |
| Joychamberlain Ltd | Health & social care | 2022 |
| JOYCHAMBERLAIN9 Ltd | Real estate | 2022 |