| Jacked Fitness Systems Ltd | Education | 2023 |
| JACKFIELD1 Ltd | Hospitality | 2025 |
| Jackknifed Juggernaut Ltd | Information & communication | 2026 |
| Jackson & Jackson's SON International Limited | Wholesale & retail | 2025 |
| Jackson Financial Limited | Professional & scientific | 2019 |
| Jackson Hogg Limited | Administrative & support | 2012 |
| Jackson Miller Ltd | Financial services | 2014 |
| Jackson Residential Limited | Real estate | 2021 |
| Jacksons Enterprises (Byker) Limited | Hospitality | 1994 |
| Jacksons Interiors Limited | Wholesale & retail | 2000 |
| Jacly Ltd | Real estate | 2024 |
| Jacques Peacock Ltd | Information & communication | 2018 |
| Jacx Limited | Administrative & support | 2017 |
| Jade Linens Ltd | Wholesale & retail | 2023 |
| Jade Power Ltd | Professional & scientific | 2024 |
| Jadenco Ltd | Wholesale & retail | 2026 |
| Jadon Enterprise Limited | Wholesale & retail | 2023 |
| Jafari Education Ltd | Education | 2024 |
| Jafaria Society | Health & social care | 2013 |
| Jaff Investments Ltd | Real estate | 2024 |
| Jafu Ltd | Construction | 2022 |
| Jagbuldings Ltd | Construction | 2026 |
| JAI Grace Property Ltd | Real estate | 2022 |
| JAI MSK UK Ltd | Hospitality | 2021 |
| Jaid Limited | Hospitality | 2016 |
| Jain Samaj Newcastle Ltd | Other services | 2024 |
| Jaipur Indian Takeaway Newcastle Ltd | Hospitality | 2025 |
| JAK Building Services Limited | Construction | 2025 |
| Jakare Coffee Ltd | Wholesale & retail | 2024 |
| Jakare Ltd | Wholesale & retail | 2019 |
| Jake Acquisitions Limited | Financial services | 2006 |
| Jake Holdings Limited | Financial services | 2006 |
| Jake Investment Limited | Financial services | 2006 |
| Jake Nominees Limited | Administrative & support | 2006 |
| Jake of ALL Trades North East Ltd | Construction | 2023 |
| Jaloub Ltd | Real estate | 2021 |
| Jaluminati Limited | Professional & scientific | 2014 |
| Jaluminati Sports Limited | Information & communication | 2015 |
| JAM JAR Jesmond Ltd | Hospitality | 2016 |
| JAM Umbrella Ltd | Manufacturing | 2017 |
| Jamarc Property & Project Management Limited | Real estate | 2001 |
| Jamdani Whickham Ltd | Hospitality | 2020 |
| James a. Jobling and Company Limited | Manufacturing | 1976 |
| James and Crossan Holdings Ltd | Professional & scientific | 2025 |
| James Christopher Consulting Ltd | Professional & scientific | 2004 |
| James Collins Quality Management Consultancy Limited | Professional & scientific | 2021 |
| James Fulton Hair Ltd | Other services | 2015 |
| James Graham Investments Ltd | Households | 2026 |
| James Industrial Services Limited | Professional & scientific | 1979 |
| James Lloyd Developments Limited | Real estate | 2014 |
| James Madden Offshore Limited | Construction | 2012 |
| James Milburn Training Ltd | Arts & recreation | 2013 |
| James Shoes Limited | Wholesale & retail | 2025 |
| James Tyres Ltd | Wholesale & retail | 2025 |
| James Wokes Plastic Surgery Limited | Health & social care | 2017 |
| James Wood (Felling) Limited | Wholesale & retail | 2019 |
| Jameson Manor Residents Management Company Limited | Households | 2019 |
| Jamfab Engineering Limited | Professional & scientific | 2024 |
| Jamh Capital Limited | Real estate | 2018 |
| Jamie Lamb 3D Limited | Information & communication | 2026 |
| Jamie Shaw Video Design Ltd | Information & communication | 2023 |
| Jamm's Hairdressing Limited | Other services | 2019 |
| Jamops Ltd | Information & communication | 2024 |
| JAN Elliott Consulting Ltd | Professional & scientific | 2017 |
| Jan's Trade Cars Ltd | Wholesale & retail | 2025 |
| Jana Shawarma Ltd | Hospitality | 2019 |
| Jane Grant Ltd | Wholesale & retail | 2018 |
| Janet Grace Neuropsychiatry Limited | Health & social care | 2017 |
| Janet Plater Management Limited | Administrative & support | 1997 |
| Janforster-Estates Limited | Real estate | 2006 |
| Janice Allan & Co Limited | Professional & scientific | 2005 |
| Jannah Apothecare Ltd | Health & social care | 2025 |
| JAP (NE) Limited | Health & social care | 2022 |
| Japanese NE1 Limited | Hospitality | 2023 |
| Jape Holdings Ltd | Real estate | 2020 |
| Jars Letting Management Ltd | Real estate | 2025 |
| Jasb Properties Ltd | Real estate | 2020 |
| Jasfoods Ltd | Hospitality | 2025 |
| Jaslin Infotech Ltd | Information & communication | 2019 |
| Jaslin Properties Ltd | Real estate | 2022 |
| Jasmin Court South Yorkshire Management Limited | Real estate | 2021 |
| Jasmin Couture Ltd | Wholesale & retail | 2026 |
| Jasmine Paul Residential Ltd | Real estate | 2025 |
| Jasmins Canapés Ltd | Hospitality | 2020 |
| Jason Friend Photography Ltd | Professional & scientific | 2007 |
| Jasper Kerr Consulting Engineers Ltd | Professional & scientific | 2017 |
| Jasper’S Coffee House Ltd | Hospitality | 2021 |
| Jass Technical Services Limited | Administrative & support | 2009 |
| JAT22 Ltd | Hospitality | 2022 |
| Jatinderdigiclique Ltd | Professional & scientific | 2025 |
| Java Properties (1) Limited | Real estate | 2017 |
| Java Properties Limited | Real estate | 2015 |
| Java Residential Limited | Real estate | 2020 |
| Javed Transport NE Limited | Transport & logistics | 2026 |
| Javi&Cris Ltd | Transport & logistics | 2026 |
| Jawa AI Ltd | Information & communication | 2024 |
| Jawaj Limited | Transport & logistics | 2025 |
| Jawspace Limited | Information & communication | 2023 |
| Jawz Trading Ltd | Wholesale & retail | 2025 |
| Jaxn Media Ltd | Information & communication | 2023 |