| IVY House Farm Management Company Limited | Households | 2024 |
| Iweb Technologies Ltd | Information & communication | 2004 |
| Iwns Consulting Ltd | Wholesale & retail | 2026 |
| Iwona Accountancy Services Limited | Professional & scientific | 2012 |
| IWT Solutions Ltd | Wholesale & retail | 2021 |
| Ixbrad Ltd | Administrative & support | 2016 |
| Iyaba Ltd | Wholesale & retail | 2022 |
| Iyli Paroi Limited | Manufacturing | 2018 |
| IZA Market Ltd | Wholesale & retail | 2026 |
| IZN Properties Ltd | Real estate | 2026 |
| J & a Collective Estates Limited | Real estate | 2023 |
| J & a Physiotherapy Ltd | Health & social care | 2007 |
| J & B Engineering Services Ltd | Professional & scientific | 2017 |
| J & G Joinery Limited | Manufacturing | 2006 |
| J & H UK Properties Ltd | Real estate | 2022 |
| J & J Sidhu Properties Limited | Real estate | 2021 |
| J & K Holdings Limited | Financial services | 2004 |
| J & M (West Midlands) Ltd | Administrative & support | 2019 |
| J & M Saloons Ltd | Hospitality | 2024 |
| J & M Supermarket Ltd | Wholesale & retail | 2021 |
| J & M Tubes Limited | Manufacturing | 2001 |
| J & R Investments UK Limited | Real estate | 2008 |
| J & S Project Limited | Administrative & support | 2006 |
| J & SC Ltd | Real estate | 2020 |
| J a Burgwin Construction Limited | Construction | 2017 |
| J a M UK Property Ltd | Real estate | 2021 |
| J and M Bedford Rentals Ltd | Real estate | 2019 |
| J and M Property Developers Ltd | Real estate | 2025 |
| J and R Plant Hire Limited | Other services | 1994 |
| J B Builders Ltd | Construction | 2018 |
| J B S Building Ltd | Construction | 2023 |
| J Banks & Co Limited | Manufacturing | 1942 |
| J Banks Holdings Limited | Professional & scientific | 2006 |
| J Banks Industries Limited | Financial services | 2011 |
| J Barton Property Investment Limited | Households | 2021 |
| J Bibb TM Services Ltd | Construction | 2020 |
| J C Garden Services (2021) Limited | Other services | 2021 |
| J D a Holdings Limited | Real estate | 2016 |
| J D a S K Recovery Ltd | Wholesale & retail | 2024 |
| J D Bookkeeping Solutions Ltd | Professional & scientific | 2015 |
| J D Cake Box Limited | Wholesale & retail | 2020 |
| J D COX Electrical Installation Limited | Wholesale & retail | 2010 |
| J Dunne Properties Ltd | Real estate | 2026 |
| J Edwards Building Contractors Limited | Construction | 2001 |
| J H Building Construction Limited | Construction | 2008 |
| J H Marshall (Holdings) Limited | Professional & scientific | 1973 |
| J H Marshall (Pressings) Limited | Manufacturing | 2007 |
| J Haul Ltd | Transport & logistics | 2011 |
| J J E Milczarek Limited | Construction | 2018 |
| J J Johnston (Farms) Limited | Agriculture & fishing | 1977 |
| J Johnson Brickwork Limited | Construction | 2020 |
| J K F Limited | Professional & scientific | 1990 |
| J K Malhi Limited | Wholesale & retail | 2018 |
| J Kamden Ltd | Health & social care | 2025 |
| J Life Investments Ltd | Real estate | 2019 |
| J M E Glass Limited | Water & waste | 2010 |
| J M Fitness Limited | Other services | 2013 |
| J M Midland Properties Limited | Construction | 2021 |
| J M Solutions and Services Limited | Professional & scientific | 2014 |
| J Mccurdy Ltd | Wholesale & retail | 2025 |
| J O Flynn Properties Ltd | Real estate | 2019 |
| J P Heating & GAS Ltd | Construction | 2025 |
| J Pugh Interiors Limited | Construction | 2011 |
| J R Assets Ltd | Real estate | 2026 |
| J R H Electrical Services Limited | Construction | 2008 |
| J R Harris Consulting Ltd | Professional & scientific | 2019 |
| J Relna Ltd | Real estate | 2021 |
| J S (Midlands) Ltd | Transport & logistics | 2025 |
| J S Builders 007 Limited | Construction | 2021 |
| J S Grainger Consultancy Ltd | Professional & scientific | 2024 |
| J S Management & IT Consultancy Ltd | Professional & scientific | 2013 |
| J S R Subsidiaries Ltd | Professional & scientific | 2014 |
| J S Sohal Limited | Administrative & support | 2003 |
| J Sandhu Transport Limited | Transport & logistics | 2024 |
| J Synergy Ltd | Information & communication | 2025 |
| J to the L Ltd | Transport & logistics | 2022 |
| J W Stone Masons Ltd | Manufacturing | 2017 |
| J Wagstaff Limited | Administrative & support | 2023 |
| J Watson Holdings Limited | Professional & scientific | 2018 |
| J Witkowski Ltd | Construction | 2023 |
| J&B Products Ltd | Wholesale & retail | 2021 |
| J&C Heating and Plumbing Limited | Construction | 2024 |
| J&D Co. Limited | Real estate | 2024 |
| J&D Distribution Limited | Wholesale & retail | 2011 |
| J&D Locum Solution Limited | Health & social care | 2022 |
| J&J ALL in One Drinks Ltd | Wholesale & retail | 2024 |
| J&J Electrical Ltd | Construction | 2016 |
| J&J Home & Holiday Lettings Ltd | Real estate | 2022 |
| J&K Ojo's Ltd | Wholesale & retail | 2025 |
| J&M Capital Properties Ltd | Real estate | 2026 |
| J&M Miracle Cleaners Ltd | Administrative & support | 2021 |
| J&S OB Limited | Information & communication | 2022 |
| J&T Wellcare Limited | Health & social care | 2016 |
| J&V Holiday Lets Limited | Hospitality | 2024 |
| J&V Property Limited | Real estate | 2018 |
| J. G. Hudson Design Services Ltd. | Professional & scientific | 1995 |
| J. J. Rudell & Co. Limited | Wholesale & retail | 1976 |
| J. Owen (UK) Ltd | Professional & scientific | 2011 |
| J. Peters Properties Limited | Real estate | 2011 |
| J. Singh & Company Limited | Professional & scientific | 1992 |