| Jaroteam Transport Ltd | Transport & logistics | 2021 |
| Jarvis & Son’S Ltd | Transport & logistics | 2019 |
| JAS Removals Ltd | Transport & logistics | 2021 |
| JAT Holdings Limited | Real estate | 1972 |
| Java Nu-Clear Power Sound Ltd | Extraterritorial | 2022 |
| Java Sound System Limited | Information & communication | 2022 |
| JAY Hipkiss Media Ltd | Information & communication | 2023 |
| Jaycee Engineering (Corby) Limited | Professional & scientific | 2004 |
| Jayplas (Corby) Limited | Wholesale & retail | 1986 |
| JB Elite Services Limited | Administrative & support | 2013 |
| JBB Ground Maintenance Ltd | Households | 2019 |
| Jbcaccessories Ltd | Wholesale & retail | 2025 |
| JBF Motors Ltd | Wholesale & retail | 2026 |
| JBR Motors Ltd | Wholesale & retail | 2024 |
| JBY Investments Limited | Real estate | 2022 |
| JC Property (Midlands) Limited | Financial services | 2021 |
| JCE Design Limited | Construction | 2016 |
| JCS Car Repairs Limited | Wholesale & retail | 2026 |
| Jctech Support Ltd. | Extraterritorial | 2012 |
| JD Tanning UK Ltd | Wholesale & retail | 2018 |
| Jeakins Weir Limited | Construction | 1973 |
| Jedar Integrated Services Limited | Information & communication | 2011 |
| Jedar Properties Limited | Households | 2025 |
| Jeff Motors Ltd | Wholesale & retail | 2024 |
| Jefl Properties Limited | Real estate | 2025 |
| Jelley Trading Co Ltd | Professional & scientific | 2025 |
| Jemini (Kettering) UK Ltd | Other services | 2018 |
| Jennie Portugal Recruitment Limited | Administrative & support | 2023 |
| Jennifer Umali Resource Limited | Administrative & support | 2023 |
| Jernice Care Limited | Public administration | 2023 |
| Jernice Properties Ltd | Real estate | 2026 |
| Jesus Christ Pentecostal Church | Other services | 2009 |
| Jeti Carwash Limited | Wholesale & retail | 2010 |
| Jevgenij Services Limited | Manufacturing | 2015 |
| Jevgenijs Larionovs Ltd | Extraterritorial | 2023 |
| Jevico Auto Ltd | Wholesale & retail | 2025 |
| Jfilms Art Limited | Information & communication | 2019 |
| JFK Property Holdings Ltd | Real estate | 2022 |
| JG Accounting Solutions Ltd | Professional & scientific | 2025 |
| JG Home & Leisure Ltd | Wholesale & retail | 2021 |
| JGD Property Ltd | Real estate | 2025 |
| JGH Transport Limited | Transport & logistics | 2018 |
| JGW8 Services Ltd | Construction | 2023 |
| JH Audio Solutions Ltd | Construction | 2019 |
| JHD Investments Ltd | Real estate | 2020 |
| Jibson Ltd | Health & social care | 2015 |
| Jirasan Ltd | Transport & logistics | 2025 |
| JJ Goodman Holdings Limited | Real estate | 2022 |
| Jj&Jk Transport Ltd | Transport & logistics | 2022 |
| Jjbs Lets Limited | Real estate | 2016 |
| JJC Building Services Ltd | Construction | 2025 |
| Jjjm Properties Limited | Real estate | 2022 |
| JK Engineering & Projects Ltd | Professional & scientific | 2024 |
| JK Malverns Limited | Transport & logistics | 2023 |
| JLI Group Properties Ltd | Real estate | 2025 |
| JLP Engineering Limited | Professional & scientific | 2024 |
| JM Engineering Solutions Ltd | Professional & scientific | 2025 |
| JM9 Limited | Real estate | 2020 |
| Jmactransportsolutions Limited | Transport & logistics | 2017 |
| JMG Property Ltd | Real estate | 2022 |
| JMM Drinks Ltd | Hospitality | 2025 |
| JMN Limited | Health & social care | 2013 |
| JNL Coachworks Limited | Wholesale & retail | 2014 |
| JNT Management Ltd | Wholesale & retail | 2022 |
| Joely’S Signature Aesthetics Ltd | Other services | 2025 |
| John Dayo Recruitment Limited | Administrative & support | 2023 |
| Johnicka Ltd | Wholesale & retail | 2026 |
| Johnny's Professional Refurbishment Ltd | Construction | 2024 |
| JOINERY4TRADE Ltd | Manufacturing | 2025 |
| Joja Living Ltd | Real estate | 2026 |
| Jokey UK Limited | Manufacturing | 2021 |
| Jolis Care Limited | Health & social care | 2020 |
| Joma Limited | Health & social care | 2013 |
| Jonas Interpreting and Translation Services Limited | Other services | 2015 |
| Jorose Ltd | Real estate | 2024 |
| Joseph Mhlanga Limited | Health & social care | 2018 |
| Josh’S Composites Limited | Professional & scientific | 2024 |
| Jozef Kiselak Ltd | Transport & logistics | 2016 |
| Jozu Shop Ltd | Other services | 2019 |
| JP Property Corby Limited | Real estate | 2024 |
| JPL Property Investments Ltd | Real estate | 2020 |
| Jprint Limited | Manufacturing | 2022 |
| JPS Motors Ltd | Wholesale & retail | 2025 |
| JPS Transport Ltd | Transport & logistics | 2024 |
| JR Grills Ltd | Hospitality | 2026 |
| JR Specialist Cars Limited | Wholesale & retail | 2015 |
| JRH Flooring Specialist (Restoration & Cleaning) Ltd | Extraterritorial | 2023 |
| Jrichards Limited | Information & communication | 2024 |
| JRN Property Holdings Limited | Real estate | 2023 |
| JRW Automotive Services Limited | Wholesale & retail | 2019 |
| JS Energy Consulting Limited | Professional & scientific | 2024 |
| JS Mediation and Consultancy Services Limited | Transport & logistics | 2025 |
| JSC Renovations Limited | Construction | 2021 |
| JSG Commercial Ltd | Real estate | 2021 |
| JSP Training Academy Ltd | Education | 2022 |
| JT Medical Services Limited | Health & social care | 2017 |
| Jtaffy Limited | Transport & logistics | 2022 |
| JTJ Services Limited | Health & social care | 2025 |
| JTY Recruitment Ltd | Administrative & support | 2018 |
| Juanne's House CIC | Real estate | 2025 |