| J & S Burman Investments Limited | Real estate | 2004 |
| J & S Fresh Fish LLP | | 2011 |
| J & S Laser Profiles Limited | Manufacturing | 1995 |
| J & T Building and Maintenance Ltd | Construction | 2022 |
| J & T Systems Limited | Information & communication | 1981 |
| J & V Alford Holdings Limited | Financial services | 2013 |
| J a F Services Limited | Manufacturing | 2001 |
| J Alford Agricultural Contractors Limited | Administrative & support | 2013 |
| J and J Property (Hampshire) Limited | Real estate | 2023 |
| J Atkins Carpentry and Joinery Ltd | Construction | 2018 |
| J B Developments (SW) Limited | Real estate | 2025 |
| J B Technical Engineering Ltd | Manufacturing | 2019 |
| J Bardolph Accountants Ltd | Extraterritorial | 2018 |
| J Brenton Ltd | Professional & scientific | 2025 |
| J Brewer Surfacing and Landscapes Ltd | Professional & scientific | 2024 |
| J C Corporate (Bedford) Ltd | Professional & scientific | 2012 |
| J C Engineering (Southern) Limited | Professional & scientific | 2018 |
| J C Shipping Services Limited | Transport & logistics | 2008 |
| J City News Ltd | Wholesale & retail | 2025 |
| J Coates Developments Ltd | Construction | 2024 |
| J D Electrical Services Limited | Manufacturing | 2000 |
| J Dayer Barbering Limited | Other services | 2022 |
| J Dewar Ltd | Construction | 2016 |
| J Digby Carpentry Limited | Construction | 2014 |
| J Gill and SON Limited | Wholesale & retail | 2003 |
| J Gray Medical Services Ltd | Health & social care | 2025 |
| J Guard Consultancy Limited | Administrative & support | 2011 |
| J H Business Services Limited | Administrative & support | 2022 |
| J H Equine Ltd | Agriculture & fishing | 2022 |
| J H Farriers Ltd | Agriculture & fishing | 2014 |
| J H Remedial Ltd | Agriculture & fishing | 2014 |
| J H Watson & Sons Limited | Agriculture & fishing | 1978 |
| J Hedges Limited | Manufacturing | 2014 |
| J J E S Limited | Construction | 2004 |
| J K Convenience Retail Ltd | Wholesale & retail | 2020 |
| J L H Transport Ltd | Transport & logistics | 2023 |
| J L P Welding Limited | Professional & scientific | 2018 |
| J L Social Care Consultancy Ltd | Health & social care | 2023 |
| J Lambert Financial Ltd | Hospitality | 2016 |
| J Lampard Electrical Ltd | Construction | 2004 |
| J P Glazing Limited | Manufacturing | 2022 |
| J P H FRY Consulting Limited | Professional & scientific | 2018 |
| J Parry & Sons General Builder Ltd | Construction | 2014 |
| J Petty Holdings Ltd | Financial services | 2024 |
| J Pirie Ltd | Other services | 2018 |
| J R Project Control Services Limited | Professional & scientific | 1994 |
| J Real Estates Ltd | Real estate | 2022 |
| J S Photography Limited | Professional & scientific | 2011 |
| J S Smart Automotive Services Ltd | Wholesale & retail | 2024 |
| J Spaintingcontractors Ltd | Construction | 2024 |
| J Still Installations Limited | Construction | 2005 |
| J Talbot Plumbing&Heating Ltd | Construction | 2021 |
| J Trinity Limited | Hospitality | 2024 |
| J Volt Electrical Limited | Construction | 2024 |
| J W Screeding Ltd | Construction | 2016 |
| J W Tooling Limited | Wholesale & retail | 1999 |
| J Wells Construction Ltd | Construction | 2024 |
| J Whistler Plant Ltd | Administrative & support | 2020 |
| J Williams Chair Frames Limited | Manufacturing | 2011 |
| J&A Marshall Automovement Division Ltd. | Transport & logistics | 2006 |
| J&A Marshall Limited | Transport & logistics | 2007 |
| J&B Property Investments Ltd | Real estate | 2019 |
| J&Ch Property Ltd | Real estate | 2021 |
| J&E Scaffolding Ltd | Construction | 2022 |
| J&G Gibbs Limited | Construction | 2006 |
| J&G Logistics Limited | Transport & logistics | 2025 |
| J&H Holdings Ltd | Real estate | 2019 |
| J&J Care Limited | Health & social care | 2017 |
| J&J Construction Fawley Ltd | Construction | 2014 |
| J&J Sector 9 Limited | Wholesale & retail | 2024 |
| J&K Companies Limited | Construction | 2023 |
| J&K Supreme Cleaning Ltd | Administrative & support | 2025 |
| J&L 4 Homes Ltd | Real estate | 2023 |
| J&L Building & Landscapes Limited | Construction | 2022 |
| J&L Consultancy Ltd | Professional & scientific | 2021 |
| J&M Stays Ltd | Real estate | 2026 |
| J&N Holdco Limited | Construction | 2020 |
| J&R Property Sales Ltd | Real estate | 2022 |
| J&R Property Specialists Limited | Real estate | 2012 |
| J&S Accountants Limited | Professional & scientific | 2003 |
| J&S Construct Ltd | Manufacturing | 2024 |
| J'Adore Events Ltd | Arts & recreation | 2021 |
| J-B European Mini Market Ltd | Wholesale & retail | 2024 |
| J-Tech Electronics Limited | Wholesale & retail | 2007 |
| J. & D. Humphrey Limited | Construction | 2002 |
| J. & S. Estates Limited | Real estate | 1994 |
| J. Bruno Construction Limited | Extraterritorial | 2009 |
| J. Collins Medals Limited | Wholesale & retail | 2003 |
| J. Nias Estate Limited | Real estate | 2018 |
| J. Stanford Acquisitions Limited | Real estate | 2023 |
| J.& L.Estates Limited | Real estate | 1937 |
| J.A. Noyce Agricultural Ltd | Agriculture & fishing | 2018 |
| J.C. Radford Site Engineering and Land Surveys Limited | Professional & scientific | 1982 |
| J.E Oilcan Ltd | Financial services | 2021 |
| J.F Practical Services Ltd | Construction | 2014 |
| J.Gulliver Plumbing and Heating Limited | Construction | 2024 |
| J.H.M.R Limited | Other services | 2015 |
| J.L. Wren Limited | Construction | 1964 |
| J.M.Y Events Ltd | Administrative & support | 2025 |
| J.W.Finding(Farms)Limited | Agriculture & fishing | 1963 |