| Mckenna Holdco Ltd | Financial services | 2026 |
| Mcknight Group Services Ltd | Construction | 2023 |
| Medicore Ambulance Service UK Limited | Health & social care | 2015 |
| Medina Opco Limited | Hospitality | 2023 |
| Merry Hill Opco Limited | Hospitality | 2023 |
| Meteor Tools Limited | Wholesale & retail | 2025 |
| MHE Trading Limited | Wholesale & retail | 2023 |
| Millbank Estate Agents Limited | Real estate | 2002 |
| Millrose Fashion Limited | Administrative & support | 2023 |
| Mirage Engineering Services Ltd | Professional & scientific | 2022 |
| MJP Groundworks and Construction EA Ltd | Construction | 2024 |
| MKH Care Ltd | Administrative & support | 2025 |
| MM Installations Limited | Construction | 2013 |
| Moda Land & Property Development Ltd | Construction | 2022 |
| Mohkan and Co Ltd | Real estate | 2025 |
| Monck Consulting Services Ltd | Professional & scientific | 2018 |
| Moore Design Build Complete Limited | Construction | 2011 |
| Moorstone Paving Ltd | Construction | 2004 |
| Motorbitz Limited | Wholesale & retail | 2020 |
| Motorsports Protection Ltd | Financial services | 2017 |
| MPS Holdings East Anglia Ltd | Construction | 2020 |
| MPW Construction Services Ltd | Professional & scientific | 2014 |
| Mtsg Limited | Information & communication | 2019 |
| Mulberry Tree (Norfolk) Limited | Hospitality | 2025 |
| Mutlu Brothers Ltd | Hospitality | 2025 |
| Mutlu Catering Ltd | Hospitality | 2023 |
| My Outdoor Media Ltd | Professional & scientific | 2022 |
| Myriad Stepping Stones Limited | Education | 2019 |
| Naish Ashby and Company Limited | | 1979 |
| Naturevape Limited | Wholesale & retail | 2016 |
| NB Rail Developments Ltd | Construction | 2024 |
| NB Rail Engineering Ltd. | Professional & scientific | 2014 |
| NBA Appliance Services Ltd | Other services | 2024 |
| NC Windows Limited | Construction | 2017 |
| Negus Haines Group Limited | Administrative & support | 2016 |
| New Buckenham Property Ltd | Construction | 2015 |
| New Walk Opco Limited | Hospitality | 2023 |
| Newall Plant Ltd | Construction | 2013 |
| Neways Group Ltd | Construction | 2020 |
| Next Move Homes Limited | Real estate | 2022 |
| Ngeo Ltd | Education | 2014 |
| Nick Hargrave Consulting Ltd | Other services | 2018 |
| Night Guru Limited | Hospitality | 2013 |
| Norfolk Brides Limited | Wholesale & retail | 2025 |
| Norfolk Custom Campers Ltd | Manufacturing | 2025 |
| Norfolk Painters Ltd | Construction | 2024 |
| Norfolk Property Limited | Real estate | 1988 |
| Norfolk Racing F4 Ltd | Education | 2021 |
| Norfolk Racing Holdings Limited | Construction | 2018 |
| Norfolk Racing Ltd | Arts & recreation | 2011 |
| Norfolk Racing Team Ltd | Professional & scientific | 2020 |
| Norfolk VEG Box Limited | Extraterritorial | 2013 |
| Norfolk Wagyu Beef Ltd | Extraterritorial | 2018 |
| Norwich Hand Therapy Practice and Plastic Surgery Rehabilitation LLP | | 2012 |
| Nova-Ton IT Limited | Construction | 1998 |
| Nsquared Ltd | Information & communication | 2023 |
| NTB Consulting Ltd | Information & communication | 2019 |
| Nutshell Doors and Windows Ltd | Construction | 2023 |
| NX13 Limited | Professional & scientific | 2024 |
| Oathill Opco Limited | Hospitality | 2023 |
| ODD Audio Guest Book Ltd | Manufacturing | 2024 |
| Office App Care Limited | Information & communication | 2015 |
| OJI Limited | Arts & recreation | 2011 |
| OL STA Ltd | Hospitality | 2025 |
| Old Buckenham Airways Ltd | Transport & logistics | 2015 |
| Old Bucks Developments Banham Ltd | Construction | 2024 |
| Old Bucks Developments Brookville Limited | Construction | 2025 |
| Old Bucks Developments Crown ST Limited | Construction | 2025 |
| Old Bucks Developments Diss Limited | Construction | 2024 |
| Old Bucks Developments Norfolk Limited | Construction | 2022 |
| Old Bucks Developments Norwich Ltd | Construction | 2024 |
| Old Bucks Developments Stradbroke Limited | Construction | 2025 |
| Old Bucks Holdings Limited | Financial services | 2022 |
| Old Bucks Homes Limited | Construction | 2022 |
| Old Bucks Properties Limited | Real estate | 2022 |
| ON the Field - Shooting Clothing & Accessories Limited | Wholesale & retail | 2013 |
| Oncard Ltd | Extraterritorial | 2025 |
| Open Data Consultants Limited | Information & communication | 2022 |
| Optimal Consultancy Associates Ltd | Administrative & support | 2011 |
| Oqlar Limited | Professional & scientific | 2017 |
| Orchard Garage (Attleborough) Ltd | Wholesale & retail | 2013 |
| Original Magazine Ltd | Information & communication | 2021 |
| Outhill Opco Limited | Hospitality | 2023 |
| Overton Cleaver LLP | | 2008 |
| P R Construction (Anglia) Ltd | Construction | 2015 |
| P. Ewin Farms Limited | Real estate | 2003 |
| Pace Group Ltd | Arts & recreation | 2019 |
| Pace Motorsport Holdings Limited | Professional & scientific | 2023 |
| Pano Services Ltd | Manufacturing | 2025 |
| Pansophy Ltd | Wholesale & retail | 2022 |
| Paratus Holdings Ltd | Professional & scientific | 2020 |
| Park Farm Opco Limited | Hospitality | 2023 |
| Patsy O'Neill Limited | Arts & recreation | 2017 |
| Paul Arthurton Transport Limited | Transport & logistics | 2020 |
| Payments Solved Ltd | Professional & scientific | 2015 |
| Pdl-Services Limited | Manufacturing | 2012 |
| Peacock Studio Paint Your Own Pottery Ltd | Arts & recreation | 2025 |
| Pensure Ltd | Professional & scientific | 2025 |
| Personal Face 2 Face Advice Limited | Financial services | 2005 |
| Philip Thorrold Limited | Arts & recreation | 2018 |