| JD Walton Limited | Manufacturing | 2018 |
| JDA Asbestos Specialists Ltd | Construction | 2022 |
| JDA Residentials Ltd | Real estate | 2023 |
| JDA Roofing Specialists Ltd | Construction | 2019 |
| JDB Procurement Ltd | Professional & scientific | 2024 |
| JDF Solutions Limited | Administrative & support | 2009 |
| JDG Performance Ltd | Wholesale & retail | 2015 |
| JDH Lighting Ltd | Construction | 2013 |
| JDL Produce Limited | Wholesale & retail | 2018 |
| JDL2 Advisory Limited | Professional & scientific | 2026 |
| Jdlp Properties Ltd | Real estate | 2024 |
| JDM Shop Ltd | Wholesale & retail | 2025 |
| JDR Installations Ltd | Construction | 2017 |
| JDS 7 Limited | Professional & scientific | 2021 |
| JDS Cleaning Ltd | Administrative & support | 2018 |
| JDS Trans Ltd | Transport & logistics | 2023 |
| JDT Cleaning Services Limited | Administrative & support | 2009 |
| JE Labrum Ltd | Information & communication | 2023 |
| Jean Elizabeth Residential Care Ltd | Health & social care | 2022 |
| Jebcom Limited | Information & communication | 2001 |
| Jedasher Limited | Health & social care | 2022 |
| Jefferson Business Assist Ltd | Administrative & support | 2024 |
| Jeffery - West Retail Limited | Wholesale & retail | 1998 |
| Jeffery West and Co Limited | Wholesale & retail | 1987 |
| Jeffery-West Estates Limited | Real estate | 2017 |
| Jeffmay Ltd | Public administration | 2018 |
| Jeffrey Plumbing and Heating Ltd | Construction | 2014 |
| Jeffs & Co Accountants Limited | Professional & scientific | 2026 |
| Jeges Limited | Wholesale & retail | 2015 |
| JEK Media Limited | Administrative & support | 2016 |
| Jelley Distilleries Limited | Wholesale & retail | 2015 |
| Jels Electrical Ltd | Construction | 2012 |
| JEM Accountancy Services Limited | Professional & scientific | 2022 |
| Jemar Limited | Real estate | 2006 |
| Jemmy Cafe Ltd | Hospitality | 2019 |
| Jems Stationers Limited | Wholesale & retail | 2002 |
| Jemscrafts Ltd | Arts & recreation | 2008 |
| Jena Performance Ltd | Professional & scientific | 2020 |
| Jenarc Ltd | Arts & recreation | 2025 |
| Jenkins Estate Agents Ltd | Real estate | 2009 |
| Jenkins Sign Installations Limited | Construction | 2018 |
| Jenmor Properties Ltd | Real estate | 2024 |
| Jennics Limited | Water & waste | 2007 |
| Jenny Epstein Paediatric Gastroenterologist Limited | Health & social care | 2022 |
| Jenyvenus Ltd | Other services | 2026 |
| Jerk.Shed Ltd | Extraterritorial | 2017 |
| Jerome Zodo Fine Art Limited | Arts & recreation | 2015 |
| Jervis & Partners Limited | Professional & scientific | 1999 |
| Jervis Financial Services Limited | Financial services | 1993 |
| Jerzy Composite Solution Ltd | Wholesale & retail | 2022 |
| Jesbuk Limited | Administrative & support | 2015 |
| Jesky Ltd | Real estate | 2026 |
| JET Dream Homes Ltd | Real estate | 2020 |
| JET Energy Consultancy Limited | Professional & scientific | 2019 |
| JET Plant Service & Repairs Ltd | Manufacturing | 2025 |
| JET Reed Limited | Wholesale & retail | 2003 |
| JET Shipping Ltd | Transport & logistics | 2021 |
| Jet's Barber Shop Ltd | Other services | 2019 |
| Jetcot Ltd | Water & waste | 2024 |
| Jetpack CSG PVT Ltd | Professional & scientific | 2024 |
| Jevgensa Ltd | Transport & logistics | 2015 |
| Jevtiling Services Ltd | Construction | 2017 |
| Jewell’S Hair Ltd | Other services | 2023 |
| Jeyes Family Properties Limited | Households | 2020 |
| Jeyes Ltd | Wholesale & retail | 2023 |
| Jeyes Plumbing and Heating Limited | Energy | 2014 |
| Jezzar Limited | Transport & logistics | 2025 |
| JF Letting Services Ltd | Real estate | 2023 |
| JF Ventures Ltd | Hospitality | 2014 |
| JFB Management Ltd | Administrative & support | 2011 |
| Jfmotorsales Limited | Wholesale & retail | 2025 |
| Jfour Quad Ltd | Real estate | 2026 |
| JFT Ltd | Professional & scientific | 2018 |
| JG Accounting Limited | Professional & scientific | 2016 |
| JG Dwellings Ltd | Real estate | 2024 |
| JG Transport Ltd | Transport & logistics | 2007 |
| JGK Wolstenholme Limited | Financial services | 2020 |
| Jgraph Holdings Ltd | Extraterritorial | 2021 |
| JGS Property Management LLP | | 2023 |
| JH Prime Logistics Limited | Transport & logistics | 2026 |
| JH UWC Limited | Extraterritorial | 2024 |
| JHA Ventures Ltd | Real estate | 2026 |
| Jhaw 1 Limited | Financial services | 2018 |
| Jhonts Limited | Transport & logistics | 2025 |
| JHP Consulting Ltd | Professional & scientific | 2018 |
| JHS Fibre Limited | Construction | 2023 |
| JIB Tyres Trading Ltd | Wholesale & retail | 2023 |
| Jibology Ltd | Professional & scientific | 2011 |
| Jida & Sons Limited | Health & social care | 2021 |
| Jiffy Print Limited | Manufacturing | 1971 |
| Jific Limited | Financial services | 2017 |
| Jigsaw Care Services Ltd | Health & social care | 2023 |
| Jigsawftware Ltd | Information & communication | 2008 |
| Jikoni Interiors Ltd | Administrative & support | 2019 |
| Jill Griffiths Limited | Real estate | 2011 |
| JIM Agnew Lighting Limited | Professional & scientific | 2016 |
| Jimmys Sports Bar Ltd | Hospitality | 2018 |
| Jimsam Healthcare Services Ltd | Health & social care | 2014 |
| Jimy Maintenance Ltd | Construction | 2019 |
| Jisla Consulting Ltd | Other services | 2018 |