| N.G. Plumbing Services Ltd | Construction | 2003 |
| N.S.E.P. Community Interest Company | Information & communication | 2007 |
| Nailed IT by Harvey Ltd | Other services | 2025 |
| Namahage Limited | Other services | 2020 |
| Namvya Limited | Wholesale & retail | 2024 |
| NAP Scaffolding Ltd | Construction | 2025 |
| National Gearboxes Ltd | Wholesale & retail | 2015 |
| National Renewable Electrical Services Limited | Construction | 2022 |
| Nature Thrills Travel Group Ltd | Administrative & support | 2025 |
| Navigate East Ltd | Wholesale & retail | 2022 |
| NB Financial Consultants Ltd | Professional & scientific | 2017 |
| NBC Ceramics Limited | Administrative & support | 2019 |
| Nbdenergy Ltd | Mining & quarrying | 2026 |
| NC & Co. Property Ltd | Real estate | 2025 |
| Neebilink Services Ltd | Information & communication | 2022 |
| Need 2 Store Limited | Transport & logistics | 2004 |
| Need a Key Limited | Administrative & support | 2024 |
| Neil Case Welding Services Ltd | Construction | 2014 |
| Neil Thorogood Services Ltd | Professional & scientific | 2012 |
| Neils Rentel Limited | Real estate | 2017 |
| Neotech Electrical Services Ltd | Construction | 2021 |
| Nethor Limited | Real estate | 2023 |
| Never Mind the JOB Spec Ltd | Administrative & support | 2020 |
| Nevillesnelly Limited | Hospitality | 2017 |
| New Embassy Cuisine Limited | Hospitality | 2025 |
| New Fusions Media Limited | Information & communication | 2023 |
| New Mortgage Solutions Ltd | Financial services | 2004 |
| New Property Solutions Limited | Households | 2016 |
| New Shang HAI Well Limited | Hospitality | 2018 |
| Newson Family Ltd | Agriculture & fishing | 2024 |
| Newtec Online Ltd | Wholesale & retail | 2025 |
| Nexgen Roofing Ltd | Construction | 2024 |
| Nfilis Limited | Health & social care | 2024 |
| NG Marine Consultants Ltd | Professional & scientific | 2020 |
| NGB Bars & Events Ltd | Hospitality | 2022 |
| NH Paving & Civil Engineering Limited | Construction | 2025 |
| Nice 2 LET 2 Limited | Real estate | 2024 |
| NICE2LET Limited | Real estate | 2024 |
| Nicholsons Solicitors LLP | | 2010 |
| Nick Harvey Consulting Ltd | Professional & scientific | 2016 |
| Nightingale House Pakefield Limited | Real estate | 2014 |
| Niki D Plumbing & Heating Limited | Construction | 2024 |
| Nikita Wilson-Sun Consultant Ltd | Professional & scientific | 2022 |
| Nikki Berry Creative Communications Ltd | Information & communication | 2017 |
| Nilgai Foods UK Ltd | Wholesale & retail | 2017 |
| Nine Foot Offshore Limited | Mining & quarrying | 2013 |
| Nisro Ltd | Wholesale & retail | 2025 |
| Nitrotech Jarvis Limited | Professional & scientific | 2015 |
| Nitrotech Ltd | Mining & quarrying | 2001 |
| NMC Inspections Ltd | Professional & scientific | 2021 |
| Noahs ARK Nursery Limited | Education | 2003 |
| Nobre Properties Limited | Real estate | 2025 |
| Nook Vintage Ltd | Wholesale & retail | 2023 |
| Norfolk & Suffolk Boating Association Ltd | Other services | 2024 |
| Norfolk & Suffolk Finance Limited | Extraterritorial | 2011 |
| Norfolk & Suffolk Security Ltd | Construction | 2024 |
| Norfolk Automatics Ltd | Wholesale & retail | 2015 |
| Norfolk Glass Repair Limited | Wholesale & retail | 2023 |
| Norfolk Marine and General Limited | Manufacturing | 2016 |
| Norfolk Village Inns Limited | Hospitality | 2006 |
| Normandale & Normandale Limited | Real estate | 2015 |
| North Sea Group Limited | Financial services | 2017 |
| North Sea Taverns Limited | Real estate | 2006 |
| North Sea Training Services Limited | Administrative & support | 2013 |
| Norton Peskett LLP | | 2010 |
| Norton Standard Co. Ltd | Professional & scientific | 2026 |
| Norwich Aviation Centre Limited | Transport & logistics | 2022 |
| Norwich Pallets Ltd | Manufacturing | 2021 |
| Noss Mayo Developments Limited | Construction | 2006 |
| Nova Aura Lifestyle Ltd | Wholesale & retail | 2025 |
| NPH Electrical Limited | Construction | 2007 |
| NR32 Investments Limited | Real estate | 2026 |
| NR33 Estates Limited | Real estate | 2023 |
| NR33 Holdings Limited | Financial services | 2023 |
| NTA (1963) Limited | Arts & recreation | 1968 |
| NTD Properties Ltd | Real estate | 2021 |
| NTI Electrical Ltd | Construction | 2022 |
| Nuglow UK Wellness Ltd | Hospitality | 2023 |
| Numeric Solution Ltd | Wholesale & retail | 2025 |
| Nutribom Limited | Manufacturing | 2024 |
| Nutrisolve Limited | Professional & scientific | 2014 |
| Nutriwolds RAW Ltd | Manufacturing | 2022 |
| NY Real Estate Ltd | Real estate | 2026 |
| O D Penfold Services Ltd | Manufacturing | 2026 |
| O T Morton Limited | Construction | 2024 |
| O. S. Supply Limited | Construction | 2024 |
| O.S. Agri Limited | Agriculture & fishing | 2022 |
| O4AROMA Limited | Wholesale & retail | 2022 |
| Oak Street Fabrications Limited | Manufacturing | 2015 |
| Oak Tree Developments Limited | Real estate | 2008 |
| Oakes Estates Limited | Real estate | 2018 |
| Oaklands Leisure Limited | Arts & recreation | 2010 |
| Oaklands Mews Management Company Limited | Households | 2018 |
| Oakley Enterprises (East Anglia) Limited | Hospitality | 2008 |
| Oakwood Developments (East Anglia) Limited | Construction | 2002 |
| Oasis AI Ltd | Information & communication | 2020 |
| Ocean Fish Bar Suffolk Ltd | Hospitality | 2025 |
| ODC RE 33 Ltd | Construction | 2026 |
| Oddfellows Arms (Lowestoft) Limited | Extraterritorial | 2009 |
| OEG Offshore Technology Limited | Information & communication | 2002 |