| Heritage West Limited | Extraterritorial | 2003 |
| Hesott Limited | Financial services | 2006 |
| High Grange Village Trust Limited | Other services | 2004 |
| Hilder and Co. Limited | Administrative & support | 1965 |
| Hilite Ltd | Manufacturing | 2021 |
| HLF Sales and Lettings Limited | Real estate | 2021 |
| HNC Consulting Ltd | Financial services | 2026 |
| Hogarth Timber Limited | Manufacturing | 2025 |
| Holmested Ltd | Information & communication | 1996 |
| Homemove (Chester-Le-Street) Limited | Real estate | 2000 |
| Homemove (Durham) Limited | Real estate | 2000 |
| Homemove (Professional) Limited | Professional & scientific | 2000 |
| Homemove (Property Management) Limited | Real estate | 2000 |
| Houghton Groundworks Ltd | Construction | 2007 |
| Howard Musgrave DNF Administration Limited | Administrative & support | 2017 |
| HS Transport Services Limited | Construction | 1990 |
| Hunton Bros Ltd | Professional & scientific | 1995 |
| Hutchin Limited | Wholesale & retail | 2025 |
| Hutchinson Mode Ltd | Wholesale & retail | 2026 |
| Hygrade Consultancy Limited | Professional & scientific | 1994 |
| I G Inspection Limited | Construction | 2019 |
| I W Adamson Limited | Other services | 2006 |
| I.B.A. Fabrications Limited | Manufacturing | 1998 |
| IBE Carse Limited | Energy | 2023 |
| IBE Haine Limited | Energy | 2024 |
| IBE Hixons Limited | Energy | 2024 |
| IBE Horse Leys Limited | Energy | 2024 |
| IBE MID Hartwood Limited | Energy | 2023 |
| IBE Polegate Limited | Energy | 2023 |
| Infinite Sounds Limited | Manufacturing | 1996 |
| Innerglass Group Limited | Financial services | 2023 |
| International Plastic Systems Limited | Wholesale & retail | 1990 |
| Inverness Holiday Homes Ltd | Hospitality | 2004 |
| J Carter Medical Ltd | Health & social care | 2018 |
| J M & a Ramsay (Contracting & Plant Hire) Limited | Construction | 2005 |
| J R a Engineering Limited | Construction | 2007 |
| J. Noble & Sons Limited | Other services | 1977 |
| J. R. Forbes Electrical Ltd | Construction | 2004 |
| J.E. Dickinson Limited | Health & social care | 1962 |
| J.J. Optical Limited | Health & social care | 1997 |
| J.P. Hunt Building Contractors Limited | Construction | 2004 |
| J.W. Wood Limited | Administrative & support | 1992 |
| James Caverhill Conservation Limited | Arts & recreation | 2002 |
| James Southern Property Group Limited | Financial services | 2022 |
| Jamie Wood Frist Limited | Wholesale & retail | 2025 |
| JAY Cctv Solutions (JCS) Ltd | Administrative & support | 2017 |
| Jennings Foodservice Limited | Wholesale & retail | 2003 |
| JJ Metcalfe & SON Ltd | Manufacturing | 2009 |
| JKB Raws Ltd | Wholesale & retail | 2022 |
| Joanne Anderson Ltd | Professional & scientific | 2024 |
| Johnsonn Limited | Wholesale & retail | 2025 |
| Jold Baxter Limited | Real estate | 2024 |
| Joshua SOL Limited | Wholesale & retail | 2025 |
| JRB Connections Ltd | Education | 2021 |
| JRW Associates Limited | Professional & scientific | 2005 |
| K Hewitt Properties Limited | Real estate | 1997 |
| Kappa Packaging North West Limited | Manufacturing | 1970 |
| Kappa Packaging South East Limited | Professional & scientific | 1919 |
| Kash Retail (UK) Limited | Wholesale & retail | 2004 |
| Kasmm Limited | Administrative & support | 2007 |
| Katmex Seaham Limited | Manufacturing | 1978 |
| KAY Queiruga Ltd | Other services | 2002 |
| Kidsfone.Com Limited | Professional & scientific | 2000 |
| Kindling Limited | Professional & scientific | 1997 |
| King Investment Properties Ltd | Real estate | 2018 |
| Kleek Apprenticeships Limited | Education | 1998 |
| Knutz Hair Salon Limited | Other services | 2003 |
| Kutz Above Limited | Other services | 2002 |
| Kutz CLS Limited | Other services | 2002 |
| L & G Plant Hire and Sales Limited | Construction | 2002 |
| Labone Castleside Limited | Manufacturing | 2004 |
| Leaf 82 Limited | Hospitality | 2021 |
| LEE Aaron Limited | Wholesale & retail | 2025 |
| Leeming Associates Limited | Professional & scientific | 2003 |
| Legacy Entertainment and Events Limited Partnership | | 2022 |
| Legal and Valuation (Land) Limited | Professional & scientific | 2002 |
| Leisure Property Holdings Limited | Extraterritorial | 2006 |
| Leybourne Urwin Limited | Construction | 1935 |
| Lightfoot Computer Services Limited | Information & communication | 1989 |
| Llooyd Limited | Wholesale & retail | 2025 |
| Location Aware Solutions Limited | Information & communication | 2005 |
| Lood Consulting Limited | Administrative & support | 2024 |
| LOW Copelaw Land LLP | | 2024 |
| Lumfen Ltd | Wholesale & retail | 2026 |
| M & L Associates Design and Build Limited | Construction | 2007 |
| M & M Property Maintenance Ltd | Construction | 2004 |
| M G Electrics (UK) Ltd | Energy | 2004 |
| M S H Contractors Limited | Water & waste | 2007 |
| M.S.B. Lift Trucks and Plant Training Limited | Administrative & support | 2006 |
| MAD Alice Theatre Company | Arts & recreation | 2006 |
| Magneco Metrel U.K. Limited | Manufacturing | 1990 |
| Maltby Colliery Limited | Mining & quarrying | 2007 |
| Maptex Limited | Information & communication | 2005 |
| Marian Engineering EOT Ltd | Professional & scientific | 2025 |
| Mark Williams Express Freight Services Limited | Transport & logistics | 1999 |
| Mascot Property Services Limited | Construction | 2007 |
| Mcfarlane Family Butchers Ltd | Wholesale & retail | 2002 |
| Mckiimm Limited | Wholesale & retail | 2025 |
| Mcnay Building & Joinery Limited | Construction | 2002 |
| Mend My Door Limited | Other services | 2022 |