| JB Retail (Cricklade) Limited | Construction | 2011 |
| JBC Properties Limited | Real estate | 2016 |
| JBM Financial Services and Bureau DE Change Limited | Transport & logistics | 2024 |
| JBM Solar Projects 12 Ltd | Construction | 2019 |
| JBM Solar Projects 13 Limited | Construction | 2019 |
| JBM Solar Projects 14 Ltd | Construction | 2019 |
| JBM Solar Projects 15 Ltd | Construction | 2019 |
| JBM Solar Projects 17 Ltd | Construction | 2019 |
| JBM Solar Projects 19 Ltd | Construction | 2019 |
| JBM Solar Projects 2 Ltd | Energy | 2019 |
| JBM Solar Projects 20 Ltd | Construction | 2019 |
| JBM Solar Projects 21 Limited | Construction | 2020 |
| JBM Solar Projects 22 Limited | Construction | 2020 |
| JBM Solar Projects 24 Limited | Professional & scientific | 2020 |
| JBM Solar Projects 25 Limited | Professional & scientific | 2020 |
| JBM Solar Projects 26 Limited | Professional & scientific | 2020 |
| JBM Solar Projects 27 Limited | Construction | 2020 |
| JBM Solar Projects 28 Limited | Construction | 2020 |
| JBM Solar Projects 29 Limited | Construction | 2020 |
| JBM Solar Projects 3 Ltd | Construction | 2019 |
| JBM Solar Projects 30 Limited | Professional & scientific | 2020 |
| JBM Solar Projects 31 Limited | Construction | 2021 |
| JBM Solar Projects 32 Limited | Construction | 2021 |
| JBM Solar Projects 33 Limited | Construction | 2021 |
| JBM Solar Projects 34 Limited | Construction | 2021 |
| JBM Solar Projects 35 Limited | Construction | 2021 |
| JBM Solar Projects 36 Limited | Construction | 2021 |
| JBM Solar Projects 37 Limited | Construction | 2021 |
| JBM Solar Projects 38 Limited | Construction | 2021 |
| JBM Solar Projects 39 Limited | Construction | 2021 |
| JBM Solar Projects 40 Limited | Construction | 2021 |
| JBM Solar Projects 41 Limited | Construction | 2022 |
| JBM Solar Projects 5 Ltd | Construction | 2019 |
| JBM Solar Projects 6 Ltd | Energy | 2019 |
| JBM Solar Projects 7 Ltd | Construction | 2019 |
| JBM Solar Projects 8 Ltd | Professional & scientific | 2019 |
| JBS Property Swindon Limited | Real estate | 2021 |
| JC (Weymouth) Ltd | Hospitality | 2024 |
| JC Co Enterprises Ltd | Construction | 2023 |
| JC Jade Ltd | Wholesale & retail | 2024 |
| JC Personal Trainer Ltd | Education | 2024 |
| JC Property Refurb Limited | Construction | 2019 |
| JCB Properties Development Ltd | Real estate | 2026 |
| Jcba Holdings Ltd | Financial services | 2017 |
| Jccio Company Ltd | Health & social care | 2021 |
| JCD Cyber Consulting Ltd | Financial services | 2025 |
| JCE Construction Ltd | Construction | 2026 |
| Jcka Consulting Limited | Real estate | 1998 |
| Jcpropertysourcing Limited | Real estate | 2024 |
| JCR Interiors Limited | Construction | 2021 |
| JCR UK Holding Limited | Financial services | 2023 |
| JCS Logistics & Delivery Limited | Transport & logistics | 2025 |
| Jcsm Group Limited | Real estate | 2015 |
| Jcsneakers Trading Ltd | Wholesale & retail | 2026 |
| JD & EE Limited | Health & social care | 2023 |
| JD Express Services Ltd | Transport & logistics | 2017 |
| JD Installations Ltd | Construction | 2012 |
| JD Kebab Burger Ltd | Hospitality | 2025 |
| JD Tyres Chippenham Ltd | Wholesale & retail | 2023 |
| JD UK Group Limited | Construction | 2017 |
| JDA Solutions Limited | Professional & scientific | 2026 |
| Jdac Limited | Extraterritorial | 2008 |
| JDB Carpentry Service Limited | Construction | 2017 |
| JDB Signs Limited | Wholesale & retail | 2014 |
| Jdjk Ltd | Construction | 2015 |
| Jdml Hair Ltd | Other services | 2018 |
| JDP Communications Ltd | Information & communication | 2018 |
| JDW Professional Services (Ipswich) Limited | Professional & scientific | 2023 |
| Jebaco Global Ltd | Wholesale & retail | 2025 |
| JED a Company Ltd | Transport & logistics | 2026 |
| JED Cleaners Ltd | Administrative & support | 2017 |
| Jedi Property Group Ltd | Real estate | 2025 |
| Jefferies & SON Decorating Co. Ltd | Construction | 2014 |
| Jefferies Mews Management Company Limited | Households | 1986 |
| Jeffery Property Group Limited | Real estate | 2025 |
| Jegr Media Ltd | Information & communication | 2025 |
| Jehqualitysolutions Ltd | Professional & scientific | 2024 |
| Jellyfish Crew and Co Ltd | Information & communication | 2024 |
| JEM Entertainment Limited | Hospitality | 2018 |
| Jemi Medical Consulting Limited | Health & social care | 2023 |
| Jennifer Louise Weddings Ltd | Other services | 2018 |
| Jensat & Co MED Services Ltd | Health & social care | 2023 |
| Jenssen VII Ltd | Professional & scientific | 1993 |
| Jeremy Smalley Consulting Ltd | Administrative & support | 2013 |
| JESS1 Property Ltd | Real estate | 2023 |
| Jesse's Construction Ltd | Construction | 2020 |
| Jessica Properties Ltd | Construction | 2023 |
| Jessica's Hair and Beauty Limited | Other services | 2013 |
| JET Agile Ltd | Information & communication | 2016 |
| JET Brickwork Ltd | Construction | 2021 |
| Jetho Ltd | Health & social care | 2024 |
| Jett Care Limited | Health & social care | 2020 |
| Jewel Flowers Ltd | Wholesale & retail | 2025 |
| Jewel in the Crown Foods Ltd | Hospitality | 2026 |
| Jewels Services Ltd | Health & social care | 2024 |
| JEY One Ltd | Wholesale & retail | 2026 |
| JEY Properties Ltd | Real estate | 2014 |
| Jey's Shopfitters Ltd | Construction | 2020 |
| JF Brown Consulting Limited | Other services | 2024 |
| JFL Construction Services Ltd | Construction | 2024 |