| Izihh Limited | Real estate | 2024 |
| Iznus Ltd | Wholesale & retail | 2018 |
| IZU Desserts Ltd | Hospitality | 2020 |
| IZU Diner Ltd | Information & communication | 2025 |
| Izza Enterprise Ltd | Extraterritorial | 2023 |
| Izzu Cafe Ltd | Hospitality | 2023 |
| J & E Marshall Finance Limited | Professional & scientific | 2013 |
| J & H Properties & Management Ltd | Real estate | 2025 |
| J & I’S Management Ltd | Real estate | 2025 |
| J & K Stainless Limited | Manufacturing | 2005 |
| J & L Industrial Services Limited | Wholesale & retail | 2000 |
| J & M Sendrove Ltd | Other services | 2012 |
| J & N Legal Services Limited | Professional & scientific | 2015 |
| J & P Commercials Ltd | Real estate | 2025 |
| J & P Consultants Ltd | Professional & scientific | 2015 |
| J & S Care Ltd | Health & social care | 2022 |
| J & S Design and Build Ltd | Construction | 2025 |
| J & T Civils Limited | Construction | 2022 |
| J a Eastwood & Co Ltd | Wholesale & retail | 2019 |
| J a R S I Mughal Builders Ltd | Construction | 2023 |
| J a Transport Ltd | Transport & logistics | 2019 |
| J and J Lally Ltd | Real estate | 2026 |
| J and M Hairdressing Limited | Other services | 2014 |
| J and T Cleaning Services Ltd | Administrative & support | 2015 |
| J Askham Marketing Ltd | Professional & scientific | 2023 |
| J B Tours (Watnall) Limited | Transport & logistics | 1998 |
| J Booth Flooring Ltd | Construction | 2020 |
| J Boyd Laurie and SON Limited | Wholesale & retail | 2000 |
| J C Building & Maintenance Limited | Construction | 2024 |
| J C Business Consultancy Limited | Professional & scientific | 2020 |
| J C H Fabrications Limited | Manufacturing | 2000 |
| J C Investment Property Ltd | Real estate | 2018 |
| J Collier Haulage Ltd | Transport & logistics | 2025 |
| J Crossley Roofing Limited | Construction | 2020 |
| J D Contractors Yorkshire Ltd | Construction | 2023 |
| J D FEE Builders Limited | Construction | 2013 |
| J D Wines Premier Limited | Wholesale & retail | 2015 |
| J Dalecki Limited | Health & social care | 2015 |
| J Davies Surgical Services Ltd | Health & social care | 2013 |
| J DOT Distributors Limited | Wholesale & retail | 2025 |
| J DOT Holdings UK Limited | Financial services | 2020 |
| J Fiaz Ltd | Wholesale & retail | 2026 |
| J H Tree & Waste Services Limited | Water & waste | 2026 |
| J Hussain Building Ltd | Construction | 2026 |
| J I Dlamini Limited | Hospitality | 2024 |
| J Ibrahim Medical Services Ltd | Health & social care | 2008 |
| J J Construction (Llandudno) Limited | Construction | 2015 |
| J K Cards Limited | Manufacturing | 2004 |
| J K Contracting Ltd | Professional & scientific | 2015 |
| J K Travel (BFD) Limited | Administrative & support | 2010 |
| J Khan Limited | Administrative & support | 2014 |
| J L Moore Ltd | Hospitality | 2020 |
| J M Cleaning Limited | Administrative & support | 2011 |
| J M Financial Securities Limited | Financial services | 2002 |
| J Manley FBA Ltd | Wholesale & retail | 2025 |
| J Martin (Leeds) Ltd | Professional & scientific | 2002 |
| J Mcdonagh & Sons Limited | Water & waste | 2014 |
| J Mitchell Builders Ltd | Construction | 2023 |
| J Nirwan Limited | Real estate | 2021 |
| J North IT Solutions Ltd | Information & communication | 2026 |
| J P Locums (BFD) Limited | Health & social care | 2016 |
| J P R Frames Limited | Manufacturing | 2012 |
| J Perfumes Online Limited | Wholesale & retail | 2024 |
| J R F Property & Investments Limited | Construction | 2015 |
| J R Property and Restorations Limited | Real estate | 2012 |
| J R Tallant Limited | Wholesale & retail | 2016 |
| J S B Construction Services Ltd | Construction | 2025 |
| J S Basra Ltd | Real estate | 2023 |
| J S Flooring (Yorkshire) Limited | Construction | 2022 |
| J S Garage Ltd | Wholesale & retail | 2020 |
| J S Roofing (Merseyside) Limited | Construction | 2026 |
| J S Transport Bradford Ltd | Transport & logistics | 2019 |
| J S U Ltd | Transport & logistics | 2021 |
| J Trimz Ltd | Other services | 2024 |
| J Verity Construction Ltd | Other services | 2021 |
| J W Cranes Ltd | Construction | 2025 |
| J W W Electrical Ltd | Construction | 2012 |
| J Wilson Property Maintenance Ltd | Construction | 2019 |
| J&B Commercials Ltd | Wholesale & retail | 2026 |
| J&I Healthcare Ltd | Health & social care | 2023 |
| J&I Lifestyle Ltd | Health & social care | 2025 |
| J&M Environmental Services (UK) Ltd | Construction | 2004 |
| J&M Signature Properties Ltd | Real estate | 2026 |
| J&R Pet Transport and Services Ltd | Transport & logistics | 2022 |
| J&S Travel International Limited | Administrative & support | 2009 |
| J&Z Consultancy Limited | Professional & scientific | 2020 |
| J-Chaya Lettings Ltd | Real estate | 2024 |
| J-Ram Limited | Information & communication | 1992 |
| J. & E. Zsigmond & Sons Limited | Wholesale & retail | 1984 |
| J. G. Walton & SON Limited | Construction | 1969 |
| J. Perfume (Popup) Limited | Wholesale & retail | 2025 |
| J. Perfumes (Leeds) Limited | Wholesale & retail | 2022 |
| J. Perfumes (Wholesales) Limited | Wholesale & retail | 2022 |
| J. Perfumes Holdings Ltd | Wholesale & retail | 2025 |
| J. Perfumes Limited | Wholesale & retail | 2015 |
| J. Perfumes Manchester Limited | Wholesale & retail | 2025 |
| J. Walker (Investments) Limited | Real estate | 1900 |
| J.A.F. Engineering Services Limited | Manufacturing | 1979 |
| J.A.R Asbestos Ltd | Construction | 2025 |
| J.B.Battye & Co. Limited | Professional & scientific | 1924 |