| Huge Limited | Professional & scientific | 1996 |
| Hunstanton Hardware Limited | Wholesale & retail | 2021 |
| Hunt Heating and Plumbing Ltd | Construction | 2024 |
| Ichiban Fusion Ltd | Hospitality | 2024 |
| IFC Landscapes Ltd | Administrative & support | 2014 |
| IN IT Limited | Information & communication | 2013 |
| Intelligent Layer Limited | Information & communication | 2024 |
| Intents Bigtops Ltd | Administrative & support | 2026 |
| Intonet Technology Limited | Information & communication | 1998 |
| Investments BGS Limited | Real estate | 2023 |
| Iscaleup Ltd | Information & communication | 2020 |
| J & J Rawlin Limited | Arts & recreation | 2016 |
| J & L Investments (Norwich) Ltd | Real estate | 2025 |
| J&L Maintenance Ltd | Manufacturing | 2021 |
| J&L Operations Ltd | Transport & logistics | 2023 |
| J. Earl Fencing Ltd | Construction | 2003 |
| J. Spindler & Sons Limited | Wholesale & retail | 1981 |
| Jack Gould Limited | Administrative & support | 2024 |
| JAM Books Limited | Professional & scientific | 2024 |
| JAM Internet Limited | Information & communication | 2017 |
| James D'S Party Time Ltd | Arts & recreation | 2015 |
| Jamie Marshall Ltd | Professional & scientific | 2011 |
| January Consulting Limited | Professional & scientific | 2007 |
| Jcopps Ltd | Wholesale & retail | 2021 |
| Jcopps Property Ltd | Real estate | 2024 |
| Jeleyjames Composite. Ltd | Manufacturing | 2026 |
| Jenelec (Europe) Ltd | Manufacturing | 2005 |
| JFD Engineeering Ltd | Manufacturing | 2024 |
| JK Locksmiths Limited | Wholesale & retail | 2022 |
| JK110 Aviation Engineering & Maintenance Limited | Professional & scientific | 2017 |
| Jlri Limited | Wholesale & retail | 2025 |
| JOE Smith Limited | Agriculture & fishing | 2015 |
| Joel VS Arthritis Ltd | Wholesale & retail | 2021 |
| John Bedwell Limited | Administrative & support | 2000 |
| JRA Installations Limited | Construction | 2009 |
| JS (Burnham Market) Limited | Real estate | 2018 |
| Just Truffles Chocolate Limited | Manufacturing | 2007 |
| Kairali South Indian Takeaway Limited | Hospitality | 2024 |
| KAM Moon (Harleston) Ltd | Hospitality | 2020 |
| KDG Surfacing Limited | Construction | 2021 |
| Kensington Court Management Company (Stowmarket) Limited | Households | 1985 |
| Kerridge Glazing Ltd | Construction | 2010 |
| Kerrison Fitness Ltd | Hospitality | 2025 |
| Kibo Homes Ltd | Construction | 2023 |
| Kimblewick Equestrian Centre (Norfolk) Ltd | Education | 2024 |
| Kirby Architecture Limited | Professional & scientific | 2020 |
| KL Robinson Ltd | Administrative & support | 2019 |
| KLE Landscaping Ltd | Administrative & support | 2023 |
| Kombat UK Limited | Wholesale & retail | 2002 |
| Konkuk Ltd | Wholesale & retail | 2022 |
| L & JB & Co Ltd | Real estate | 2024 |
| L I Property Developments Ltd | Construction | 2022 |
| Labelcraft Signs Limited | Manufacturing | 2006 |
| Lambert Livesley King Ltd | Real estate | 2013 |
| LD Leisure Ltd | Hospitality | 2024 |
| Leland Limited | Construction | 2021 |
| Lemken UK Limited | Wholesale & retail | 2000 |
| Level UP Studios Ltd | Hospitality | 2020 |
| Liddycleave Limited | Real estate | 2016 |
| Lidgate Business Support Limited | Professional & scientific | 2015 |
| Lime Tree Court Residents Association Limited | Households | 1981 |
| LMR (East Anglia) Ltd | Administrative & support | 2025 |
| LR90 Limited | Information & communication | 2015 |
| LVJ D Limited | Professional & scientific | 2025 |
| M Peck Contracting Limited | Agriculture & fishing | 2023 |
| M&H Civil Engineering Limited | Construction | 2007 |
| M. Keeble Limited | Professional & scientific | 2005 |
| Mancroft Communications Ltd | Professional & scientific | 2020 |
| Manoy Limited | Real estate | 2006 |
| Maple Spectrum Ltd | Construction | 2016 |
| Marqueesbigtop Limited | Arts & recreation | 2011 |
| Mary Aspall Limited | Administrative & support | 2014 |
| Maxwell’S Comp Shop Ltd | Wholesale & retail | 2025 |
| Mayflower Trucks Limited | Wholesale & retail | 2006 |
| MB Carpentry Contractors Ltd | Construction | 2018 |
| Mcdm Transport Ltd | Transport & logistics | 2024 |
| Mel's Fruits Limited | Wholesale & retail | 2013 |
| Meredith Sculpture Ltd | Arts & recreation | 2013 |
| Merlin MUD Services Limited | Administrative & support | 2006 |
| Metfield Hall Farm Limited | Administrative & support | 2001 |
| Metfield Stores C.I.C. | Wholesale & retail | 2006 |
| MG Finance Partners Ltd | Professional & scientific | 2025 |
| MHE Consulting Ltd | Professional & scientific | 2015 |
| Michael Martin Consultancy Ltd | Information & communication | 2015 |
| Michael Olliffe Ltd | Construction | 2017 |
| MID Norfolk Construction Ltd | Construction | 2020 |
| Milsted Hughes Limited | Education | 2019 |
| Miriyad Ltd | Professional & scientific | 2020 |
| Mobile Barbecues (East Anglia) Limited | Other services | 1961 |
| Montec Systems Ltd | Manufacturing | 2010 |
| Morf Limited | Hospitality | 2025 |
| Motorsport Harnessing Limited | Manufacturing | 2018 |
| Moving Partnership Ltd | Transport & logistics | 2000 |
| MR TOM K Ltd | Professional & scientific | 2025 |
| Mummery Property Ltd | Real estate | 2026 |
| Newson Plasterers Limited | Construction | 2024 |
| NGP Carpentry Ltd | Construction | 2017 |
| Nicola Slattery Limited | Education | 2004 |
| Norfolk & Suffolk Electricians Ltd | Construction | 2006 |
| Norfolk & Suffolk Plastering Ltd | Construction | 2022 |