| J M Sporting Limited | Administrative & support | 2026 |
| J Potter (Bungay) Limited | Professional & scientific | 2022 |
| J Potter Limited | Professional & scientific | 1998 |
| Jaks Property Limited | Real estate | 2020 |
| Jazza Home and Gifts Limited | Wholesale & retail | 2006 |
| JDW Environmental Ltd | Professional & scientific | 2011 |
| John Ashley Recruitment Limited | Administrative & support | 2019 |
| JRG Asset Developments Ltd | Real estate | 2024 |
| Jutjut Limited | Information & communication | 2025 |
| KCH Renewable Limited | Wholesale & retail | 2013 |
| KDS Property Services Limited | Construction | 2023 |
| Key Endeavours Group Limited | Manufacturing | 2021 |
| Kiely Property Services Ltd | Construction | 2023 |
| Kitchen Creation Services Limited | Manufacturing | 2022 |
| Kitsch Corner Ltd | Wholesale & retail | 2025 |
| KJT Composites Ltd | Manufacturing | 2024 |
| Knife Box Digital Limited | Professional & scientific | 2012 |
| Kumba Support Ltd | Health & social care | 2021 |
| Kwantek Limited | Information & communication | 2017 |
| LAN Synergy East Ltd | Construction | 2010 |
| Lavender Eight Ltd | Wholesale & retail | 2022 |
| Lazzari HR Solutions Limited | Administrative & support | 2023 |
| LBR Architecture Ltd. | Professional & scientific | 1999 |
| LE Camion Gourmand DE Paris Limited | Wholesale & retail | 2024 |
| LEE Lewis Developments Limited | Construction | 2019 |
| LEE Lewis Electrical Limited | Construction | 2012 |
| Leet Hill Management Co Limited | Households | 2022 |
| Leet Hill Properties Limited | Real estate | 2025 |
| Linstead Garage Ltd | Wholesale & retail | 2012 |
| LMC Aesthetics Limited | Health & social care | 2024 |
| Locum-Exec Limited | Real estate | 1981 |
| Loddon Motor TEC Ltd. | Wholesale & retail | 2012 |
| Lodestar International Limited | Professional & scientific | 2022 |
| London Media Productions Ltd | Information & communication | 2025 |
| Lootlair Ltd | Wholesale & retail | 2023 |
| Louie J Holdings Limited | Construction | 2022 |
| Lowther Hospitality Limited | Professional & scientific | 1989 |
| Luke Wright Limited | Information & communication | 2024 |
| Lyrical in Vite Entertainment Ltd | Professional & scientific | 2020 |
| M J Cook Farming Limited | Agriculture & fishing | 2017 |
| MAC Renovations Limited | Construction | 2013 |
| Mackenze-David Events Ltd | Hospitality | 2017 |
| Madfox Group Limited | Administrative & support | 2015 |
| Magpie and Tweed Educational Limited | Education | 2024 |
| Manthorpe Window Cleaning Limited | Administrative & support | 2013 |
| Mark Anthony Plumbing and Heating Limited | Construction | 2017 |
| Mark Thompson Farriers Limited | Professional & scientific | 2011 |
| Markell (Norfolk) Ltd | Real estate | 2017 |
| Mason Property Group Ltd | Professional & scientific | 2019 |
| Masters Business Consultancy Limited | Professional & scientific | 2016 |
| Maui Waui Events Ltd | Administrative & support | 2013 |
| MAX Industries Ltd | Wholesale & retail | 2025 |
| MB Farming Limited | Agriculture & fishing | 2018 |
| MED. Produce Limited | Wholesale & retail | 1999 |
| Medihire Personnel Ltd | Health & social care | 2022 |
| Mediquip Ltd | Manufacturing | 2012 |
| Megabyte IT Limited | Information & communication | 2016 |
| Metfield Films Ltd | Information & communication | 2019 |
| Midas Forecourt Services Ltd | Construction | 2018 |
| Milne Electrical Limited | Construction | 2019 |
| Mind UN Limited | Professional & scientific | 2022 |
| Mindhype Limited | Health & social care | 2025 |
| Mission Scaffolding Ltd | Construction | 2026 |
| Mj&Lj Transport Ltd | Transport & logistics | 2025 |
| MM FIC Ltd | Real estate | 2001 |
| Moore & Crowley Limited | Manufacturing | 2024 |
| Morgan-Yates Consulting Ltd | Information & communication | 2020 |
| Mosscliff Power 8 Limited | Energy | 2014 |
| Motorcycle Products Limited | Manufacturing | 2002 |
| MRB Financial Ltd | Financial services | 2014 |
| Multineed Limited | Real estate | 2000 |
| Multitek Vehicle Hire Ltd | Wholesale & retail | 2017 |
| Mystery Hare Ltd | Professional & scientific | 2022 |
| MZL Motors Ltd | Wholesale & retail | 2019 |
| Méhes-Miller Consulting Limited | Professional & scientific | 2024 |
| N D & K L Catchpole Limited | Construction | 2003 |
| N H Black Construction Limited | Construction | 2015 |
| N5 Plastering Limited | Construction | 2008 |
| Neboair Ltd | Transport & logistics | 2023 |
| Newor Marine Services Ltd | Professional & scientific | 2024 |
| Nightfall Automotive Ltd | Wholesale & retail | 2025 |
| Niki.B Solutions Ltd | Administrative & support | 2012 |
| Norfolk & Suffolk Aviation Museum Limited | Arts & recreation | 1980 |
| Norfolk and Suffolk Carpet Fitter Ltd | Construction | 2022 |
| Norwich Homes Ltd | Construction | 2008 |
| Norwich Joinery Ltd | Manufacturing | 2026 |
| Nursey Sheepskin Limited | Wholesale & retail | 2019 |
| Oclee Place Management Company Limited | Households | 2019 |
| OHC Holdings Limited | Financial services | 2019 |
| OHC Investments Limited | Real estate | 2019 |
| Ojcs Consultancy Ltd | Administrative & support | 2024 |
| Olipa Theatre Company Ltd | Health & social care | 2023 |
| Omni Tend Limited | Information & communication | 2023 |
| Onemana Limited | Hospitality | 2025 |
| Orchard Drive Broome Management Company Limited | Households | 2009 |
| Orchard House Computers Limited | Information & communication | 1998 |
| Orchids Property Developments Ltd | Real estate | 2016 |
| Orchids Rentals Limited | Real estate | 2019 |
| Outney Meadow Limited | Wholesale & retail | 2020 |
| Owla Limited | Professional & scientific | 2015 |