| J R Large Sales and Marketing Limited | Administrative & support | 2007 |
| J S Development Group Ltd | Construction | 2025 |
| J Transport Group Ltd | Transport & logistics | 2024 |
| J Whelan Decorating and Refurbishment Limited | Construction | 2009 |
| J Y Classics Limited | Wholesale & retail | 2006 |
| J&C Works Ltd | Construction | 2025 |
| J&Co Limited | Hospitality | 2019 |
| J&D Andrews (SUB Depot) Limited | Professional & scientific | 2018 |
| J&J Future Holdings Limited | Financial services | 2025 |
| J&M Designs Ltd | Manufacturing | 2012 |
| J&Mh Financial Services Limited | Financial services | 2011 |
| J&R Coaches Ltd | Transport & logistics | 2018 |
| J. & J. Pneumatics Limited | Wholesale & retail | 1977 |
| J. a. Fell Optometry Limited | Health & social care | 2002 |
| J.D.S HOL Limited | Real estate | 2019 |
| J.K General Building Ltd | Construction | 2025 |
| J.M.C. Electrical & Build Ltd | Construction | 2019 |
| J.Needham Builders Limited | Real estate | 1963 |
| J.P. Marketing & Management Services Limited | Professional & scientific | 1990 |
| J.R Services Plumbing and Heating Limited | Construction | 2021 |
| J.R.S. Repairs Ltd | Manufacturing | 2016 |
| J4S Security Services Ltd | Administrative & support | 2019 |
| JA Halls Consulting Ltd | Information & communication | 2025 |
| JA Refurbishments Ltd | Construction | 2025 |
| Jaaq Limited | Education | 2021 |
| JAB Care Limited | Health & social care | 2025 |
| Jabeen Enterprises Ltd | Wholesale & retail | 2025 |
| Jacc Consulting Limited | Professional & scientific | 2010 |
| Jace Air Conditioning Limited | Energy | 2020 |
| Jachubservices Ltd | Transport & logistics | 2022 |
| Jacinsa Limited | Other services | 1999 |
| Jack & Jack Building Limited | Construction | 2014 |
| Jack and Jackson Accountancy Limited | Professional & scientific | 2020 |
| Jack Jubb Limited | Arts & recreation | 2022 |
| Jack Lisi Properties Ltd | Real estate | 2020 |
| Jack Lisi Quantity Surveying Services Ltd | Professional & scientific | 2012 |
| Jack of Glass Limited | Construction | 2017 |
| Jackie Palmer Stage School Limited | Arts & recreation | 2008 |
| Jacks & Co Gifts Ltd | Extraterritorial | 2016 |
| Jackson & Seddon Ltd | Wholesale & retail | 2017 |
| Jackson Bates Limited | Professional & scientific | 2007 |
| Jackson EMC Limited | Professional & scientific | 2024 |
| JAD Plastering Limited | Construction | 2022 |
| Jada Property Group Limited | Real estate | 2016 |
| Jade Beason Ltd | Professional & scientific | 2021 |
| Jade Corporation Ltd | Wholesale & retail | 2025 |
| Jagadamba Ltd | Information & communication | 2022 |
| Jago Recovery Services Ltd | Transport & logistics | 2021 |
| Jaguar Sporting Ventures Ltd | Arts & recreation | 2024 |
| JAH Commercial Services Ltd | Wholesale & retail | 2020 |
| JAI Ganesh Limited | Information & communication | 2011 |
| Jakediscounts Ltd | Other services | 2026 |
| Jakfh Services Ltd | Manufacturing | 2022 |
| James & Sons Roofing and Guttering Ltd | Construction | 2025 |
| James Ashgrove Ltd | Wholesale & retail | 2025 |
| James Dean Services Limited | Construction | 2026 |
| James Donald Ltd | Professional & scientific | 2023 |
| James Drew Vehicle Services Ltd | Wholesale & retail | 2016 |
| James Harvey Construction Ltd | Construction | 2023 |
| James Hill Travels Limited | Administrative & support | 2024 |
| James Morgan Advisory Services Ltd | Professional & scientific | 2025 |
| James Orchard (Holmer Green) Management Company Limited | Households | 2019 |
| James Smith Agricultural Services LLP | | 2013 |
| James UK Estates Ltd | Real estate | 2024 |
| James William Diner Ltd | Hospitality | 2020 |
| James-Pye Lighting Ltd | Information & communication | 2025 |
| Jamie G Entertainment Ltd | Other services | 2013 |
| Jan'Z Tailoring & Alteration Ltd. | Professional & scientific | 2017 |
| Janaan Limited | Hospitality | 2022 |
| Janatpreet Hughes Property Ltd | Real estate | 2026 |
| Janb Consult Limited | Information & communication | 2026 |
| Janed Group Ltd | Wholesale & retail | 2026 |
| Janet Anne Developments Ltd | Construction | 2014 |
| Jannah Homes Ltd | Real estate | 2024 |
| Janrax Ltd | Wholesale & retail | 2016 |
| Japanese World Exports Limited | Wholesale & retail | 2022 |
| Jarbud Ltd | Construction | 2026 |
| JAS Kandore Ltd | Wholesale & retail | 2016 |
| Jasmine Park (Whirley) Management Company Limited | Extraterritorial | 2009 |
| JAV Motor Corp Ltd | Wholesale & retail | 2010 |
| JAVE11 Professional Services Ltd | Professional & scientific | 2025 |
| Jawluxe Ltd | Wholesale & retail | 2026 |
| JAX Capital Limited | Financial services | 2023 |
| Jayem Building Services Limited | Construction | 2012 |
| JAZ Jewels Ltd | Manufacturing | 2024 |
| JAZ Michelle Ltd. | Real estate | 2015 |
| Jazz's Beauty Room Ltd | Other services | 2023 |
| JB Brokers Limited | Financial services | 2017 |
| JB Oballes Ltd | Health & social care | 2023 |
| JBB Logistics Ltd | Transport & logistics | 2019 |
| JBD Rail Management Consultancy Limited | Professional & scientific | 2014 |
| JBF Enterprises Ltd | Information & communication | 2026 |
| JBL Associates Limited | Construction | 2016 |
| JBL Designs Limited | Professional & scientific | 2009 |
| JBS Luxury Homes Limited | Manufacturing | 2022 |
| JC Accommodations Ltd. | Real estate | 2024 |
| JC Consultec Limited | Professional & scientific | 2010 |
| JC Sourcing Ltd | Real estate | 2024 |
| Jccgestates Ltd | Real estate | 2024 |
| JCD Spot on Cleaning Ltd | Administrative & support | 2016 |