| Haztank Services Limited | Manufacturing | 1992 |
| HC 1322 LLP | | 2005 |
| HCC Investment Holding Limited | Financial services | 2019 |
| Heap Economiser Limited | Manufacturing | 1978 |
| Heart and Hands Recruitment Agency Ltd | Administrative & support | 2025 |
| Heartrumentals Ltd | Manufacturing | 2020 |
| Heirloom Antiques Limited | Wholesale & retail | 1973 |
| Helge Hoel Consultancy Ltd | Professional & scientific | 2019 |
| Help Your Claim Limited | Administrative & support | 2009 |
| Heywood Studio Limited | Manufacturing | 2011 |
| HH Trading Ltd | Wholesale & retail | 2026 |
| HIB Enterprise Limited | Hospitality | 2017 |
| Himedica Ltd. | Manufacturing | 1997 |
| HIQ Properties Ltd | Real estate | 2022 |
| Hive & Hops Ltd | Hospitality | 2024 |
| HM Trade Ltd | Wholesale & retail | 2023 |
| HOH Electrical Contractors Limited | Construction | 2003 |
| Holdco DK Limited | Information & communication | 2019 |
| Holt Holdings (UK) Limited | Financial services | 2011 |
| Homes of Choice Ltd | Extraterritorial | 2005 |
| Homrush Ltd | Wholesale & retail | 2022 |
| Horizon BEE Tech Ltd | Information & communication | 2026 |
| House of Hair and Beauty (Middleton) Ltd | Other services | 2016 |
| Howard Builders (Southport) Limited | Construction | 2013 |
| HP Property (International) Ltd | Real estate | 2016 |
| Hylex Limited | Real estate | 2001 |
| IAG Lloyds Limited | Real estate | 2021 |
| IC Realisations Ltd | Wholesale & retail | 2009 |
| ID Cloud Services Ltd | Information & communication | 2015 |
| Ideas Marketing Limited | Wholesale & retail | 2006 |
| IDO103 Ltd | Real estate | 2024 |
| Ienw Limited | Other services | 2014 |
| India Foods Limited | Wholesale & retail | 2025 |
| Infinity Works Ltd | Wholesale & retail | 2021 |
| Innovasnack Ltd | Manufacturing | 2012 |
| Inspec International Limited | Professional & scientific | 1988 |
| Inspire Tech UK Ltd | Wholesale & retail | 2003 |
| Inspired Infinity Limited | Construction | 2024 |
| Integrated Ultrasonic Processors Limited | Manufacturing | 1992 |
| Intel Corporation (UK) Limited | Professional & scientific | 1973 |
| Interglobe Wholesale Ltd | Wholesale & retail | 2018 |
| Investigation and Testing Services Limited | Professional & scientific | 2024 |
| IR Realisations 2024 Limited | Administrative & support | 2012 |
| Irlam Associates Group Ltd | Administrative & support | 2014 |
| ISM Holdings Limited | Water & waste | 2000 |
| ISW Proholdings Ltd | Real estate | 2019 |
| Ivaf Holding B Ltd | Financial services | 2020 |
| J Cairns Joinery Ltd | Construction | 2004 |
| J H Birtwistle Limited | Manufacturing | 2009 |
| J H Brickwork Ltd | Construction | 2006 |
| J T Resource Ltd | Transport & logistics | 2002 |
| J. Taylor (Haulage Contractor) Limited | Transport & logistics | 2005 |
| Jacob Developments Limited | Energy | 2010 |
| Janice Couture Ltd | Manufacturing | 2026 |
| Jasmin Manchester Ltd | Hospitality | 2020 |
| Jaxxons Group Limited | Professional & scientific | 2022 |
| Jean Bennett Properties Limited | Households | 2020 |
| Jennifer Young Limited | Manufacturing | 2020 |
| Jewel Glow Design Limited | Wholesale & retail | 2025 |
| JFK (UK) Limited | Construction | 2013 |
| JFX Global Ltd | Wholesale & retail | 2020 |
| Jist Studios Limited | Information & communication | 2009 |
| John Mussell Limited | Construction | 2002 |
| John Sutton Developments Limited | Construction | 2000 |
| Joseph Adamson (Hyde) Limited | Transport & logistics | 1936 |
| JP Medical Consultancy Limited | Health & social care | 2017 |
| JPG Management Limited | Financial services | 2019 |
| K Agencies Limited | Wholesale & retail | 2006 |
| K Europe Holding Company Limited | Administrative & support | 2015 |
| K J V Furniture Industries Limited | Wholesale & retail | 2012 |
| Karslakes Limited | Professional & scientific | 2005 |
| Kashmir Development Foundation | Health & social care | 2006 |
| Kelcorn Limited | Professional & scientific | 1993 |
| Kelf | Administrative & support | 2001 |
| Kellogg Company of Great Britain,Limited | Manufacturing | 1924 |
| Kellogg Group Limited | Professional & scientific | 2004 |
| Kellogg Hong Kong Holding Company Limited | Administrative & support | 2015 |
| Kellogg Latin America Holding Company (One) Limited | Administrative & support | 2010 |
| Kellogg Latin America Holding Company (Two) Limited | Administrative & support | 2010 |
| Kellogg Management Services (Europe) Limited | Manufacturing | 1996 |
| Kellogg Manchester | Administrative & support | 2001 |
| Kellogg Marketing and Sales Company (UK) Limited | Manufacturing | 1996 |
| Kellogg Supply Services (Europe) Limited | Manufacturing | 1996 |
| Kellogg U.K. Holding Company Limited | Professional & scientific | 1996 |
| Kellogg UK Minor Limited | Professional & scientific | 2004 |
| Kellogg UK Services Limited | Professional & scientific | 1933 |
| Kelmill Limited | Professional & scientific | 1981 |
| Kelpac Limited | Professional & scientific | 1977 |
| Kent & Sussex Properties Ltd. | Construction | 2004 |
| Kenworthy Consulting Limited | Professional & scientific | 2014 |
| Key Business Solutions Limited | Professional & scientific | 2004 |
| Khral Ltd | Wholesale & retail | 2022 |
| Kindred Spirits Limited | Wholesale & retail | 2005 |
| Kishorn Specialist Contractors Limited | Construction | 2000 |
| Koinonia Limited | Manufacturing | 1974 |
| Kpar Limited | Administrative & support | 2016 |
| Kpej Property Management Ltd | Real estate | 2025 |
| KTD Business Services Limited | Professional & scientific | 2013 |
| L.M.C. Freight Services Limited | Transport & logistics | 1979 |
| Landgrove Securities Limited | Real estate | 1992 |