| Jarnheim CIC | Arts & recreation | 2025 |
| Jaymel Limited | Professional & scientific | 2009 |
| JB Aviation (ENG) Limited | Manufacturing | 2023 |
| JB108 Ltd | Real estate | 2018 |
| Jbdlh Ltd | Information & communication | 2017 |
| Jcpm Landscaping Ltd | Construction | 2025 |
| JDL Properties Ltd | Real estate | 2015 |
| Jeff Bowcock Associates Ltd | Administrative & support | 2015 |
| JEM Craft Limited | Manufacturing | 2003 |
| Jemadan Limited | Extraterritorial | 1995 |
| Jetgreen Joinery Ltd | Construction | 2025 |
| Jetstream Properties Limited | Real estate | 2010 |
| JFT Boxing Ltd | Arts & recreation | 2024 |
| JFT Security Ltd | Administrative & support | 2026 |
| JJ Myriad Ltd | Professional & scientific | 2025 |
| JJG Distribution Ltd | Wholesale & retail | 2024 |
| JM Deliveries Ltd | Transport & logistics | 2025 |
| Jmds Bars Ltd | Hospitality | 2025 |
| John David Decorating UK Ltd | Construction | 2015 |
| Jones Watches Limited | Wholesale & retail | 2026 |
| Josh Hocking Limited | Wholesale & retail | 2022 |
| Joyful Property Limited | Real estate | 2017 |
| JPC Decor Limited | Construction | 2006 |
| JPJ (NW) Ltd | Professional & scientific | 2023 |
| JR Property Lettings Limited | Real estate | 2021 |
| JRP Management Services Limited | Real estate | 2018 |
| JRP Real Estate Limited | Real estate | 2025 |
| JSH Housing Ltd | Real estate | 2023 |
| JUA Medical Staffing Ltd | Health & social care | 2015 |
| Juicy Property Limited | Real estate | 2008 |
| Juicy Software Limited | Information & communication | 2018 |
| Jumpd Productions Ltd | Information & communication | 2022 |
| JW Construction Engineering Ltd | Professional & scientific | 2014 |
| JW Properties NW Ltd | Construction | 2023 |
| K-Tec Electrical & Technical Services Limited | Construction | 2016 |
| K9-6 Protection Ltd | Administrative & support | 2026 |
| Kahanui Holdings Limited | Financial services | 2026 |
| Kaisl Ltd | Agriculture & fishing | 2025 |
| Kalil Weheishi Limited | Health & social care | 2024 |
| Kaneya Ltd | Real estate | 2024 |
| Karpa Engineering Solutions Ltd. | Manufacturing | 2014 |
| Karpa Holdings Ltd | Financial services | 2025 |
| Karpa Property Solutions Ltd | Real estate | 2025 |
| Kate Lamb Waxing Ltd | Other services | 2019 |
| Kcmartin Ltd | Wholesale & retail | 2019 |
| Keaman Holdings Limited | Administrative & support | 2018 |
| Kedu Propertys Ltd | Real estate | 2024 |
| Keiller Ltd | Manufacturing | 2024 |
| Keith Taylor Transport Ltd | Transport & logistics | 2025 |
| Kevin Slater Scaffold Services Ltd | Construction | 2018 |
| KG Motorsport Engineering Ltd | Arts & recreation | 2025 |
| Khanam Properties Ltd | Real estate | 2023 |
| Kiddimax Limited | Wholesale & retail | 2018 |
| Kids Hospital Books Ltd | Information & communication | 2020 |
| Kilgo UK Limited | Real estate | 2024 |
| Kingcarpcompetitions Limited | Wholesale & retail | 2025 |
| Kingscourt Assets Ltd | Financial services | 2025 |
| Kirkstone Ambleside Limited | Hospitality | 2025 |
| KK Fryer Properties Ltd | Real estate | 2025 |
| KLM Property Holdings Ltd | Real estate | 2025 |
| KOI Competitions Ltd | Wholesale & retail | 2022 |
| Kovio Limited | Administrative & support | 2026 |
| Ktiva Group Limited | Real estate | 2025 |
| Ktmc Property Limited | Real estate | 2021 |
| L & J Property Management (Lytham) Limited | Real estate | 2018 |
| Lady Charme Limited | Wholesale & retail | 2023 |
| Ladybird Bookkeeping and Accountancy Services Ltd | Professional & scientific | 2026 |
| Lancashire Home Inspection Limited | Professional & scientific | 2010 |
| Lancashire Hygiene Supplies Ltd | Wholesale & retail | 2021 |
| Lancashire Plumbing and Heating Limited | Construction | 2012 |
| Landswood Developments Ltd | Construction | 2016 |
| Last Drop Properties Limited | Real estate | 2015 |
| Laura Duncan Financial Services Ltd | Professional & scientific | 2025 |
| Lavis and Burke Limited | Other services | 1963 |
| Lawsons Court Management Company Limited | Households | 1970 |
| Lawswood Management Company Freehold Limited | Households | 2025 |
| Lawswood Management Company Ltd | Households | 2020 |
| LBC Turbine Solutions Ltd | Manufacturing | 2026 |
| LCP Property Management Limited | Real estate | 2020 |
| Ldbarkerservices Ltd | Manufacturing | 2016 |
| LE Feast (Blackpool) Ltd | Hospitality | 2020 |
| LE Feast (Bolton) Ltd | Hospitality | 2023 |
| LE Feast (Rochdale) Ltd | Hospitality | 2022 |
| LE Feast (Wigan) Ltd | Hospitality | 2023 |
| Lebus International Engineers Limited | Manufacturing | 1962 |
| LEE for Service Limited | Wholesale & retail | 1990 |
| Leemas Scaffold Training and Assessment Consultancy Ltd | Construction | 2017 |
| Legalaid Ltd | Professional & scientific | 2026 |
| Leki Cars Limited | Administrative & support | 2021 |
| Leon Locum Limited | Wholesale & retail | 2024 |
| Leos Fast Foods Ltd | Hospitality | 2025 |
| Lesley Fenton Properties Limited | Professional & scientific | 2013 |
| Letting Solutions Blackpool Limited | Households | 2016 |
| Lily Belle Children's Boutique Ltd | Wholesale & retail | 2025 |
| Linton Consultancy Limited | Administrative & support | 2025 |
| Lion City Property Limited | Real estate | 2023 |
| Little George's Nursery School Limited | Health & social care | 2017 |
| Little Joy Emporium Ltd | Manufacturing | 2017 |
| Lmcs Developments Ltd | Real estate | 2018 |
| LMK Business Services Ltd | Information & communication | 2016 |