| Ist-Data Ltd | Manufacturing | 2025 |
| Istanbul Grill Ltd | Administrative & support | 2017 |
| IT WOW NW Ltd | Information & communication | 2022 |
| It's a Dog's Life ST Helens Limited | Other services | 2024 |
| Ivory Vista Limited | Information & communication | 2024 |
| Izzy Sowley Ltd | Professional & scientific | 2026 |
| J & K Joinery Limited | Construction | 2018 |
| J England Pharmacy Limited | Wholesale & retail | 2011 |
| J Farrar Homes Ltd | Households | 2024 |
| J Harrison Plumbing & Heating Ltd | Construction | 2017 |
| J J Hutton Limited | Real estate | 2005 |
| J Knight Property Solutions Ltd | Real estate | 2020 |
| J Neill Decorating Services Limited | Construction | 2008 |
| J P Commercials Limited | Wholesale & retail | 2025 |
| J P Gilmore Ltd | Administrative & support | 2016 |
| J S Decorating (NW) Limited | Administrative & support | 2014 |
| J&J Project Management Limited | Information & communication | 2022 |
| J&P Minibus Travel Ltd | Transport & logistics | 2025 |
| J&R Facilities Management Limited | Construction | 2025 |
| J. Isherwood Limited | Transport & logistics | 2025 |
| J.Ashcroft Ltd | Manufacturing | 2014 |
| J.B. & B. Leach (Lettings) Limited | Real estate | 2011 |
| J.B. & B. Leach Limited | Real estate | 1998 |
| J.F. Commercial Consultants Limited | Administrative & support | 2016 |
| J.F.K Transport Ltd | Transport & logistics | 2025 |
| J.L Cladding & Windows Ltd | Construction | 2026 |
| J39 Property Ltd | Real estate | 2024 |
| J4SOCIAL Ltd | Other services | 2024 |
| JAC Electrical Services (UK) Limited | Construction | 2010 |
| Jacam Ltd | Professional & scientific | 2019 |
| Jack Bassett.Set Ltd | Construction | 2025 |
| Jackj Media Limited | Wholesale & retail | 2003 |
| Jackoebe Ltd | Wholesale & retail | 2021 |
| Jackson FAB Ltd | Manufacturing | 2019 |
| Jackson Street Tyres Limited | Wholesale & retail | 2016 |
| Jacksons DG Limited | Wholesale & retail | 2020 |
| Jacques Property Group Ltd | Real estate | 2021 |
| Jade’S Vision Ltd | Education | 2023 |
| James Alexandra Properties Limited | Real estate | 2024 |
| Jameshenrycatering Ltd | Hospitality | 2024 |
| Jamesjackharry Ltd | Manufacturing | 2014 |
| Jamie Callaghan Studios Ltd | Education | 2025 |
| JAN Labs Ltd | Professional & scientific | 2025 |
| Jannel Investments Ltd | Real estate | 2025 |
| Jaro & KAT Construction Ltd | Construction | 2023 |
| JAS Transport Northwest Ltd | Manufacturing | 2023 |
| Jaydees Hospitality Limited | Hospitality | 2018 |
| Jays (Rainford) Ltd | Hospitality | 2019 |
| Jbautosandrecovery Ltd | Wholesale & retail | 2024 |
| JBK Roofing Services Limited | Construction | 2022 |
| Jbpharm Ltd | Wholesale & retail | 2022 |
| JC BIM Solutions Ltd | Professional & scientific | 2022 |
| JC Drives and Patios Ltd | Construction | 2026 |
| JC Finance Services Limited | Administrative & support | 2015 |
| JCL Leisure Ltd | Financial services | 2024 |
| JCP Property Group Limited | Households | 2025 |
| JCW Solutions Limited | Professional & scientific | 2021 |
| JDI Site Services Ltd | Construction | 2023 |
| JDL Building Company Limited | Construction | 2025 |
| JE Tyre Shop Limited | Administrative & support | 2023 |
| Jeda Consulting Limited | Professional & scientific | 2026 |
| Jehova Jireh Limited | Health & social care | 2014 |
| Jemima Lily Aesthetic Limited | Other services | 2026 |
| Jeneration Beauty Limited | Other services | 2017 |
| Jensen Brown Limited | Wholesale & retail | 2015 |
| JES Capital and Investments Limited | Financial services | 2021 |
| Jess Fishwick Medical Services Limited | Health & social care | 2024 |
| Jessica Sixsmith Limited | Professional & scientific | 2024 |
| Jfk's Cleaning Services Ltd | Administrative & support | 2021 |
| Jfrttr Property Ltd | Real estate | 2024 |
| Jgtab Ltd | Extraterritorial | 2023 |
| JH Entertainment Enterprises Ltd | Arts & recreation | 2025 |
| JH Integrated Systems Ltd | Construction | 2025 |
| JIM Engineering Limited | Professional & scientific | 2011 |
| JJ Freedom Limited | Administrative & support | 2020 |
| Jj's Ices Limited | Wholesale & retail | 2024 |
| JJC Medics Ltd. | Health & social care | 2011 |
| JJF Engineering Services Ltd | Wholesale & retail | 2004 |
| JK Fabs and Welding Ltd | Manufacturing | 2021 |
| JK Water Ltd | Water & waste | 2021 |
| JKK Builders Limited | Construction | 2022 |
| JKK Property Limited | Construction | 2025 |
| JL Handyman Services Ltd | Construction | 2024 |
| Jl&Ce Pettinger Holdings Limited | Administrative & support | 2020 |
| JLD Professional Car Care Limited | Wholesale & retail | 2019 |
| JLF Consultancy Ltd | Professional & scientific | 2023 |
| JLG Property Maintenance Ltd | Construction | 2024 |
| JLK Property Management Ltd | Construction | 2024 |
| JLP Switchgear Services Limited | Professional & scientific | 2019 |
| Jlpenders Limited | Hospitality | 2026 |
| Jlppt Ltd | Other services | 2019 |
| JLW Retreats Ltd | Real estate | 2025 |
| JM Consultations Ltd | Professional & scientific | 2020 |
| JMB Leisure Limited | Hospitality | 2023 |
| JMB Management Consultancy Ltd | Professional & scientific | 2025 |
| Jmbc (Building Contractors) Limited | Construction | 2004 |
| JME Contracting Services Ltd | Professional & scientific | 2025 |
| Jmilan's Mini Mart Ltd | Wholesale & retail | 2024 |
| JML Hardware Limited | Wholesale & retail | 2003 |
| Jmpc Property Company Limited | Households | 2025 |