| Ivory Tower Ventures Limited | Construction | 2019 |
| Ivorè Beauty Atelier Ltd | Other services | 2026 |
| Ivplayer Limited | Information & communication | 2018 |
| IVY Quarters Ltd | Real estate | 2023 |
| Ivystone Ltd | Professional & scientific | 2024 |
| Iwacu Delivery Ltd | Transport & logistics | 2023 |
| Iwealth Financial Ltd | Financial services | 2021 |
| Iwealth Ltd | Financial services | 2012 |
| Iwear International Limited | Transport & logistics | 2009 |
| IWH UK Ltd | Professional & scientific | 2024 |
| IX9 Ltd | Wholesale & retail | 2026 |
| Ixana Living Limited | Real estate | 2025 |
| Ixana Property Limited | Real estate | 2023 |
| Ixleeds Limited | Information & communication | 2011 |
| IXP Holdings Limited | Financial services | 2023 |
| IY Properties Ltd | Real estate | 2024 |
| IYS Consultancy Limited | Education | 2013 |
| IZ Consulting Ltd | Administrative & support | 2011 |
| Izabella Fashions Limited | Wholesale & retail | 2007 |
| IZE Ventures Ltd | Health & social care | 2019 |
| Izgara (Leeds) Limited | Hospitality | 2021 |
| Izonil Trading Limited | Wholesale & retail | 2009 |
| IZR Plumbing & Heating Ltd | Construction | 2023 |
| IZU Services UK Limited | Health & social care | 2019 |
| Izzymax Limited | Professional & scientific | 2020 |
| J & a Buchan Property Limited | Real estate | 2017 |
| J & a Buchan Services Ltd | Health & social care | 2014 |
| J & a Kiely Medical Services Ltd | Health & social care | 2023 |
| J & B Brining Ltd | Arts & recreation | 2023 |
| J & B Foods Limited | Wholesale & retail | 2006 |
| J & C Consulting Services Ltd | Information & communication | 2016 |
| J & C Foods (Doncaster) Limited | Hospitality | 2011 |
| J & D Assets Ltd | Real estate | 2018 |
| J & E Consulting Services Limited | Construction | 2020 |
| J & G Estates Limited | Real estate | 2002 |
| J & H Domestic Appliances Ltd | Manufacturing | 2016 |
| J & J Property Development & Investment Ltd | Construction | 2025 |
| J & K Hornby Limited | Financial services | 2014 |
| J & K Traders Ltd | Wholesale & retail | 2011 |
| J & L Kitchens and Interiors Limited | Wholesale & retail | 2017 |
| J & M Excavations Limited | Wholesale & retail | 1983 |
| J & M Shaw (Garforth) Limited | Health & social care | 2000 |
| J & P Plant Hire Ltd | Administrative & support | 2020 |
| J & P Reinforced Concrete Specialists Ltd | Construction | 2019 |
| J & V Printing Services Limited | Manufacturing | 1985 |
| J a Conroy Ltd | Transport & logistics | 2015 |
| J a Kelly Electrical Limited | Construction | 2014 |
| J a Murphy Scaffolding Limited | Construction | 2017 |
| J a Properties Leeds Limited | Real estate | 2025 |
| J a Upholstery Limited | Manufacturing | 1996 |
| J Addison Properties Ltd | Real estate | 2025 |
| J and M Patel Ltd | Wholesale & retail | 2022 |
| J Andrews Holdings Ltd | Financial services | 2025 |
| J Arnold Consultancy Limited | Administrative & support | 2014 |
| J B HGV Services Limited | Manufacturing | 2013 |
| J B Meays & SON Limited | Wholesale & retail | 2014 |
| J B Property Investing Ltd | Real estate | 2024 |
| J Bentley Estates Ltd | Households | 2017 |
| J Berwin Ltd | Wholesale & retail | 2026 |
| J Birch Estates Ltd | Real estate | 2020 |
| J Black Consulting Limited | Professional & scientific | 2023 |
| J Boyes Holdings Limited | Financial services | 2023 |
| J Bradley Wind Services Limited | Manufacturing | 2026 |
| J Browne Developer Services Limited | Construction | 2014 |
| J Browne Plant Limited | Administrative & support | 2020 |
| J Buchan Flooring Limited | Construction | 2011 |
| J Cole Accounting Limited | Professional & scientific | 2009 |
| J Cole Electrical Ltd | Construction | 2022 |
| J Colgan Electrical Limited | Construction | 2018 |
| J Cooper Properties Limited | Real estate | 2016 |
| J D Parking Consultants Limited | Administrative & support | 2008 |
| J D Ultrasonics Limited | Manufacturing | 1999 |
| J D Williams Developments Ltd | Health & social care | 2017 |
| J E Moran Properties Ltd | Real estate | 2022 |
| J E Winter Ltd | Households | 2020 |
| J Earl Gardening Services Limited | Administrative & support | 2016 |
| J Ediale Ltd | Wholesale & retail | 2021 |
| J F Plastics Ltd | Manufacturing | 1999 |
| J Fastfood Ltd | Hospitality | 2026 |
| J Fletcher Ltd | Real estate | 2019 |
| J Gallagher Consultants Limited | Administrative & support | 2016 |
| J Grant & SON Ltd | Real estate | 2025 |
| J Group Homes Ltd | Real estate | 2024 |
| J H C Communications Limited | Information & communication | 2008 |
| J H Davenport & Sons Limited | Manufacturing | 1912 |
| J H Watson Ground Rent Investment Ltd | Real estate | 2018 |
| J H Watson Residential Property Investment Ltd | Real estate | 2018 |
| J Hanson Groundworks Ltd | Construction | 2020 |
| J Harling Decorators Limited | Construction | 2002 |
| J Harris Capital Limited | Professional & scientific | 2025 |
| J Haynes Ltd | Professional & scientific | 2018 |
| J Hickman Transport Limited | Wholesale & retail | 2012 |
| J Hopkinson Consulting Limited | Other services | 2018 |
| J Hull Consulting Ltd | Professional & scientific | 2021 |
| J J Fireworks Ltd | Wholesale & retail | 2026 |
| J J Foundation Limited | Real estate | 2017 |
| J K Brief Stay Options Ltd | Hospitality | 2023 |
| J K Long Limited | Administrative & support | 2019 |
| J K Plasterers Limited | Construction | 2014 |
| J K Seymour Limited | Wholesale & retail | 2003 |