| Jithus Limited | Wholesale & retail | 2014 |
| JJ Accounts and Bookkeeping Services Limited | Professional & scientific | 2014 |
| JJ Digital UK Ltd | Professional & scientific | 2018 |
| JJ Dynamic Solutions Ltd | Real estate | 2011 |
| JJ Engineering Solutions Ltd | Professional & scientific | 2019 |
| JJ House Letting Company Limited | Real estate | 2023 |
| JJ Plus Ltd | Administrative & support | 2015 |
| JJ Southern Limited | Hospitality | 2023 |
| JJ Woodcraft Ltd | Manufacturing | 2014 |
| JJ4 Ltd | Hospitality | 2024 |
| Jjak Consultancy Limited | Professional & scientific | 2019 |
| JJB Healthcare Services Limited | Health & social care | 2018 |
| JJC Consultancy Ltd | Professional & scientific | 2024 |
| JJH Group Limited | Financial services | 2019 |
| Jjhaven Limited | Public administration | 2022 |
| JJM (UK) Ltd | Information & communication | 2010 |
| Jjms Consulting Limited | Information & communication | 2024 |
| JJP Planning Ltd | Professional & scientific | 2024 |
| Jjplumbing Ltd | Construction | 2022 |
| JJR Mechanical & Electrical Ltd | Construction | 2013 |
| JJR Property Ltd | Construction | 2019 |
| JJS Cider Limited | Wholesale & retail | 2023 |
| JJS Party Hire Ltd | Arts & recreation | 2020 |
| JJS Property Holdings Ltd | Real estate | 2025 |
| JJS Technical Limited | Professional & scientific | 2012 |
| Jjubs Limited | Construction | 2024 |
| Jjvibes Ltd | Professional & scientific | 2026 |
| JJZ. Ltd | Professional & scientific | 2022 |
| JK Food Ltd | Hospitality | 2017 |
| JK Laundry Co Limited | Other services | 2025 |
| JK Moor Properties Limited | Real estate | 2025 |
| JK Plant Ltd | Construction | 2017 |
| JK Powerflush UK Ltd | Construction | 2020 |
| JK Restaurants Limited | Hospitality | 2014 |
| JKA Consulting Services Ltd | Information & communication | 2017 |
| Jklion Ltd | Transport & logistics | 2025 |
| Jkrose Engineering Ltd | Professional & scientific | 2025 |
| JKS Medical Ltd | Health & social care | 2013 |
| JKS Window Cleaners Ltd | Administrative & support | 2017 |
| JL Nails 59A Ltd | Other services | 2026 |
| JLA Flooring and Tiling Limited | Construction | 2013 |
| JLA Management Ltd | Real estate | 2025 |
| JLC Technology Ltd | Professional & scientific | 2013 |
| JLD Projects Ltd | Administrative & support | 2009 |
| JLG Gyms Ltd | Arts & recreation | 2026 |
| Jlgl Limited | Professional & scientific | 2018 |
| JLH Consultants Ltd | Professional & scientific | 2011 |
| JLK Immigration Ltd. | Professional & scientific | 2022 |
| JLK Solution Limited | Administrative & support | 2024 |
| JLL Golf Ltd | Arts & recreation | 2025 |
| Jlnh Ltd | Agriculture & fishing | 2018 |
| JLP Consulting Group Ltd | Administrative & support | 2025 |
| JLR Marine Projects Ltd | Professional & scientific | 2025 |
| JLR Technical Solutions Ltd | Professional & scientific | 2024 |
| Jlss Solutions Limited | Health & social care | 2025 |
| JLW Hospitality Ltd | Hospitality | 2024 |
| JM & C Holdings Ltd | Real estate | 2017 |
| JM & SM Consulting Limited | Information & communication | 1998 |
| JM Gyms Limited | Arts & recreation | 2024 |
| JM Plastering Ltd | Construction | 2025 |
| JM Postal System Ltd | Transport & logistics | 2019 |
| JM Properties South Ltd | Households | 2024 |
| JM Quantity Surveying Ltd | Professional & scientific | 2026 |
| Jm&Ms Limited | Hospitality | 2026 |
| JMB Project Consultants Ltd | Information & communication | 2012 |
| JMB Studio Ltd | Professional & scientific | 2022 |
| JMC Builders Ltd | Construction | 2012 |
| JMC Property Management Company (South) Limited | Households | 2026 |
| JMC Scaffolding Limited | Construction | 2020 |
| Jmcad Ltd | Professional & scientific | 2024 |
| JMD Brickwork Limited | Construction | 2016 |
| JME Aviation Ltd | Manufacturing | 2019 |
| JMG Events Ltd | Arts & recreation | 2026 |
| JML Interiors (UK) Ltd | Construction | 2011 |
| Jmlt Limited | Construction | 2017 |
| JMM Wellness & Fitness Limited | Wholesale & retail | 2023 |
| Jmo'Donnell Ltd | Professional & scientific | 2014 |
| JMP Marine Services Ltd | Professional & scientific | 2020 |
| JMS Building and Carpentry Solutions Limited | Construction | 2017 |
| JMS Constructionss Ltd | Construction | 2019 |
| JMS South Ltd | Hospitality | 2021 |
| JMS Supply Chain Services Ltd | Professional & scientific | 2016 |
| JN Consultancy Services Limited | Construction | 2015 |
| JNE Health Care Ltd | Health & social care | 2018 |
| JNL Contracting Ltd | Agriculture & fishing | 2016 |
| JNL Technologies Ltd | Professional & scientific | 2024 |
| Jnmcommerce Ltd | Wholesale & retail | 2025 |
| JNS Technical Ltd | Information & communication | 2017 |
| Jnsb Ltd | Transport & logistics | 2018 |
| JO & S Limited | Wholesale & retail | 2010 |
| JO Craig Pharma Consulting Limited | Professional & scientific | 2019 |
| JO Ventures Limited | Transport & logistics | 2020 |
| JO White Consulting Ltd | Professional & scientific | 2023 |
| Jo&Tom Limited | Real estate | 2018 |
| Jo's Sports Therapy Limited | Arts & recreation | 2015 |
| JOA Rentals Ltd | Real estate | 2025 |
| Joanne Griffin Ltd | Administrative & support | 2020 |
| Joanne Joyce Business & Finance Support Limited | Administrative & support | 2017 |
| JOB Connect Hub Limited | Administrative & support | 2025 |
| Jobeda Ltd | Health & social care | 2020 |