| Litponta Limited | Administrative & support | 2012 |
| Little Tree House Media Ltd | Information & communication | 2026 |
| Living Property Waveney Lettings & Management Ltd | Real estate | 2009 |
| LJD Therapies Limited | Other services | 2018 |
| Locanity Limited | Information & communication | 2015 |
| Logvoice Ltd | Information & communication | 2026 |
| Longview Electrical Ltd | Construction | 2019 |
| Lottie Limited | Administrative & support | 2003 |
| Lowes Services Ltd | Construction | 2010 |
| Ltsf Limited | Wholesale & retail | 2006 |
| M & P Pubs Limited | Hospitality | 2025 |
| M & R Relish Ltd | Hospitality | 2014 |
| M&J Hunt Limited | Construction | 2023 |
| Maastech Limited | Construction | 2014 |
| Maclean Property Partnership Limited | Real estate | 2018 |
| Maer's Ltd | Wholesale & retail | 2020 |
| Manor Maintenance Services Limited | Other services | 2017 |
| MAP Surveys Ltd | Professional & scientific | 2011 |
| Mark Doubleday Building Contractors Ltd | Construction | 2026 |
| Market Regulation Limited | Administrative & support | 2015 |
| Marmalade Cafe's Ltd | Hospitality | 2022 |
| Masters Professional Services Ltd | Professional & scientific | 2024 |
| Masterstroke Creative Ltd | Professional & scientific | 2025 |
| Mayhew Agricultural Limited | Manufacturing | 2024 |
| MBD Coaching Ltd | Public administration | 2022 |
| MC Property Revolutions Ltd | Real estate | 2025 |
| Mcdaniel Construction Limited | Construction | 2000 |
| MCT Electrical ( East Anglia ) Ltd | Energy | 2015 |
| Mechanical Craft Engineering Limited | Manufacturing | 2014 |
| Mechboards Ltd | Wholesale & retail | 2017 |
| Meddents Plus Ltd | Hospitality | 2022 |
| Meemamak Limited | Hospitality | 2023 |
| Meen Holdings Limited | Real estate | 2018 |
| Merrells Growers Ltd | Agriculture & fishing | 2018 |
| MF Sporting Limited | Wholesale & retail | 2015 |
| MH Goals Ltd | Manufacturing | 2016 |
| Mibs Ltd | Information & communication | 2008 |
| Mighty Scaffolding East Anglia Ltd | Construction | 2016 |
| Mili Mendez Ltd | Manufacturing | 2024 |
| Mill House Engineering Services Limited | Professional & scientific | 2013 |
| Millie’S Blinds Ltd | Manufacturing | 2019 |
| Miniature Marvels Ltd | Professional & scientific | 2024 |
| Misl Limited | Administrative & support | 2008 |
| Mistsgone Consultancy Ltd | Professional & scientific | 2010 |
| MJS Vehicle Services Ltd | Transport & logistics | 2024 |
| MJT OIL & GAS Ltd | Mining & quarrying | 2016 |
| Mobile and Laptop Repair Centre Ltd | Manufacturing | 2020 |
| Mobile Engineering Services Ltd | Professional & scientific | 2021 |
| Molineaux Investment Services LLP | | 2008 |
| Moorsight Limited | Professional & scientific | 2025 |
| Morley's Bike Sales Limited | Wholesale & retail | 2017 |
| Moxonuk Ltd | Transport & logistics | 2024 |
| MR Books Limited | Wholesale & retail | 2021 |
| MR MR. Salon Supplies Ltd | Administrative & support | 2017 |
| MR Peacock Holdings Ltd | Financial services | 2023 |
| MR Singh Financial Ltd | Financial services | 2024 |
| MRN Holdings Limited | Financial services | 2017 |
| Mulberry Kitchen Studios Limited | Construction | 2014 |
| Mundford Poultry Limited | Agriculture & fishing | 1981 |
| Museum House Management Limited | Real estate | 2014 |
| My Adworld Limited | Professional & scientific | 2015 |
| N Clark Security Installations Ltd | Administrative & support | 2023 |
| N J Liddell & Co Limited | Professional & scientific | 2003 |
| N M Beccles Ltd | Wholesale & retail | 2024 |
| N.F.C. Consultancy Services Ltd | Mining & quarrying | 2004 |
| Name App Limited | Information & communication | 2020 |
| Nature’S Nook Glamping Ltd | Hospitality | 2026 |
| Nautilus Environmental Ltd | Professional & scientific | 2023 |
| NBG Structures Ltd | Professional & scientific | 2024 |
| Neil Investments Company Limited | Construction | 1980 |
| Nelson Autocraft Limited | Wholesale & retail | 2003 |
| Nelson Business Centre Limited | Real estate | 2005 |
| Ness Business Solutions Limited | Administrative & support | 2026 |
| New Discovery Financial Services Ltd | Financial services | 2015 |
| Newshawk Limited | Information & communication | 2017 |
| Newstead Joinery Limited | Manufacturing | 2020 |
| Nextpick Suppliers UK Ltd | Wholesale & retail | 2025 |
| Nini Property Investments Limited | Real estate | 2023 |
| NM Gregson Limited | Professional & scientific | 2026 |
| NO BAD Feet Ltd | Health & social care | 2025 |
| NO Bull Coaching Ltd | Arts & recreation | 2026 |
| Noko Retreats Limited | Hospitality | 2023 |
| Norfolk Accommodation Ltd | Hospitality | 2021 |
| Norfolk Heritage Builders Ltd. | Construction | 2015 |
| Norfolk Landfill Limited | Other services | 1985 |
| North Suffolk Storage Ltd | Information & communication | 2009 |
| Northside Engineering UK Limited | Manufacturing | 2006 |
| NOW GET Qualified Limited | Other services | 2012 |
| Nrep Ltd | Wholesale & retail | 2025 |
| NSC Enterprises Limited | Real estate | 2021 |
| NSC Tool Supplies Ltd | Wholesale & retail | 2012 |
| Nutri-Spread Limited | Agriculture & fishing | 2016 |
| Oak Fired Ltd | Hospitality | 2017 |
| Oak Gardens Ltd | Administrative & support | 2018 |
| Oaks Farm and Carp Fishery UK Ltd | Other services | 2020 |
| Oasis Leisure & Entertainment Ltd | Administrative & support | 2021 |
| OBS Scaffolding Ltd | Construction | 2014 |
| ODD Socks Limited | Wholesale & retail | 2016 |
| OG Printer LAB Limited | Wholesale & retail | 2026 |
| Old School Henstead Educational Trust Limited(The) | Education | 1979 |