| J.O.G. Aesthetics Ltd | Other services | 2024 |
| J3S Infra Ltd | Construction | 2017 |
| JA Property Investment Holdings Ltd | Real estate | 2021 |
| Jaac Media Ltd | Information & communication | 2026 |
| Jaadi Limited | Financial services | 2009 |
| Jaani K Ltd | Wholesale & retail | 2025 |
| Jackdev Construction Limited | Construction | 2018 |
| Jackson Linen Ltd | Wholesale & retail | 2026 |
| Jacksonology Ltd | Wholesale & retail | 2021 |
| Jacobs Cake World & Taste Buds Limited | Hospitality | 2011 |
| Jacobs Natalie Grace Healthcare Limited | Health & social care | 2019 |
| Jacobs Physiotherapy Ltd | Health & social care | 2023 |
| JAD Residential Ltd | Real estate | 2022 |
| JAG Entreprise Ltd | Wholesale & retail | 2026 |
| Jagadhri Trading Ltd | Wholesale & retail | 2026 |
| Jagi UK Limited | Construction | 2024 |
| Jagstar Property Ltd | Construction | 2022 |
| JAI Collections Ltd | Wholesale & retail | 2024 |
| JAI Estate Agents Ltd | Real estate | 2015 |
| JAI Local Ltd | Wholesale & retail | 2020 |
| JAI Veeru Dhaba Ltd | Hospitality | 2026 |
| Jain Property Management Ltd | Real estate | 2024 |
| Jaiveen Investment Limited | Real estate | 2023 |
| Jaiveeru Convenience Store Ltd | Wholesale & retail | 2026 |
| Jak's Garage Ltd | Wholesale & retail | 2019 |
| Jakeman Trading Limited | Wholesale & retail | 2018 |
| Jakubowski Decor Ltd | Construction | 2018 |
| Jalali & Co. Ltd | Hospitality | 2023 |
| JAM R Restaurants Ltd | Hospitality | 2024 |
| JAM Taxi Service Ltd | Transport & logistics | 2024 |
| Jamallamas Limited | Manufacturing | 2025 |
| James Henry Resource Partners Limited | Administrative & support | 2026 |
| Jamil & Sons Limited | Wholesale & retail | 2025 |
| Jammin Club Limited | Arts & recreation | 2025 |
| Jammy Construction Ltd | Construction | 2016 |
| Jamsons Enterprise Ltd | Wholesale & retail | 2019 |
| JAN DE Rijk Transport Limited | Transport & logistics | 1988 |
| Jane Sara Ltd | Wholesale & retail | 2019 |
| Jannat Investments Ltd | Real estate | 2025 |
| Janoon Gourmet (T/A Chatora) Ltd | Hospitality | 2024 |
| Janoon Restaurant Ltd | Hospitality | 2021 |
| Janson Global Limited | Wholesale & retail | 2016 |
| Japanese Auto Trader London Ltd | Wholesale & retail | 2023 |
| JAR Transport Ltd | Transport & logistics | 2022 |
| Jaron Trade Ltd | Wholesale & retail | 2016 |
| JAS Bajwa Haulage Ltd | Transport & logistics | 2025 |
| Jasayansh Ltd | Real estate | 2026 |
| Jasbir Vora & Amargeet Vora Ltd | Real estate | 2021 |
| Jash Limited | Wholesale & retail | 2002 |
| Jashan Haulage Ltd | Transport & logistics | 2025 |
| Jasika UK Designer Ltd | Wholesale & retail | 2013 |
| Jasleen Birmingham Limited | Wholesale & retail | 2026 |
| Jasmine George Limited | Real estate | 2022 |
| Jasmine Trading Limited | Wholesale & retail | 2013 |
| Jasmit (UK) Ltd | Real estate | 2018 |
| Jaspreet Singh UP Limited | Construction | 2025 |
| Jass Aulakh Ltd | Transport & logistics | 2024 |
| Jass Roofing and Building Limited | Construction | 2025 |
| Jassi Builders Group Ltd | Construction | 2025 |
| Jaswal and Co Limited | Professional & scientific | 2016 |
| Jaswal Group Ltd | Construction | 2024 |
| Javed Properties Ltd | Real estate | 2020 |
| Jaworski Property Ltd | Real estate | 2017 |
| Jaworski Property North Ltd | Real estate | 2026 |
| Jawwid Ltd | Education | 2021 |
| JAY ESS GAS & Electric Ltd | Construction | 2023 |
| JAY Foods Limited | Transport & logistics | 2011 |
| JAY Sweet Mart Ltd | Manufacturing | 2020 |
| JAY T Builders Ltd | Construction | 2024 |
| JAY Two EN Three Ltd | Wholesale & retail | 2023 |
| Jaya Solutions Ltd | Administrative & support | 2026 |
| Jayahe Group Ltd | Wholesale & retail | 2021 |
| Jayakeshav Ltd | Wholesale & retail | 2024 |
| Jayhawk Consulting Ltd | Information & communication | 2014 |
| Jaykyu Ltd | Wholesale & retail | 2025 |
| Jays Professional Services Limited | Transport & logistics | 2013 |
| JAZ Online World Ltd | Wholesale & retail | 2019 |
| Jazm Assets Management Limited | Real estate | 2025 |
| Jazm Properties Ltd | Real estate | 2024 |
| Jazz Construction Ltd | Construction | 2022 |
| Jazz Haulage Ltd | Transport & logistics | 2025 |
| Jazz's Munch Box Limited | Hospitality | 2019 |
| Jazzy Food & Wine Ltd | Wholesale & retail | 2026 |
| Jazzy Vapes Ltd | Wholesale & retail | 2025 |
| JB Health & Care Services Ltd | Health & social care | 2025 |
| JB Local Ltd | Wholesale & retail | 2026 |
| JBC Hospitality Ltd | Other services | 2022 |
| JBR Contractors Ltd | Energy | 2017 |
| Jbss & Sons Investment Enterprises Ltd | Real estate | 2018 |
| JBU Enterprise Ltd | Health & social care | 2012 |
| JCK Contracts Limited | Construction | 2014 |
| JCM Facilities Services Ltd | Administrative & support | 2022 |
| JD Chechi Construction Ltd | Construction | 2024 |
| JD MED Services Limited | Financial services | 2011 |
| JDG Consultancy Ltd | Professional & scientific | 2014 |
| Jdmk Consultancy Ltd | Professional & scientific | 2021 |
| JDN Global Logistics Ltd | Transport & logistics | 2026 |
| JDR UK Properties Ltd | Real estate | 2026 |
| JDZ Property Ltd | Real estate | 2021 |
| Jeet & Meet Property Ltd | Real estate | 2025 |