| Norfolk Beach Cleans CIC | Other services | 2021 |
| Norfolk Broads Tourist Information & Activity Centre Limited | Information & communication | 2013 |
| Norfolk Caister Ltd | Hospitality | 2019 |
| Norfolk Carpentry Ltd | Manufacturing | 2024 |
| Norfolk Ceilings and Interiors Limited | Construction | 2010 |
| Norfolk Coast Developments Limited | Construction | 2008 |
| Norfolk Conservation Limited | Real estate | 2015 |
| Norfolk Contracts Limited | Information & communication | 2005 |
| Norfolk County Developments (Brundall) Ltd | Construction | 2015 |
| Norfolk County Developments Ltd | Construction | 2013 |
| Norfolk County Living Ltd | Construction | 2021 |
| Norfolk Easy Store Ltd | Wholesale & retail | 2025 |
| Norfolk Exterior Cleaning Ltd | Administrative & support | 2024 |
| Norfolk Family Retreats Ltd | Extraterritorial | 2022 |
| Norfolk Food and Drink Ltd | Hospitality | 2025 |
| Norfolk Greyhound Racing Company Limited | Arts & recreation | 1938 |
| Norfolk Healthcare Limited | Wholesale & retail | 2010 |
| Norfolk Healthcare TC Limited | Wholesale & retail | 2025 |
| Norfolk Hire Ltd | Administrative & support | 2011 |
| Norfolk Hose Services Limited | Manufacturing | 2013 |
| Norfolk Leisure and Lettings Ltd | Arts & recreation | 2026 |
| Norfolk Medical Imaging Ltd | Health & social care | 2025 |
| Norfolk Mobility Scooters Ltd | Wholesale & retail | 2016 |
| Norfolk Murugan Temple Limited | Other services | 2025 |
| Norfolk Music Publishing Limited | Information & communication | 2002 |
| Norfolk Nights Ltd | Real estate | 2022 |
| Norfolk Nutrients Limited | Wholesale & retail | 2023 |
| Norfolk Paws Paddock Ltd | Other services | 2025 |
| Norfolk Pipework Limited | Construction | 2014 |
| Norfolk Plumbing, Heating and Renewables Ltd | Construction | 2016 |
| Norfolk Refurbishments Ltd | Construction | 2021 |
| Norfolk Residence Ltd | Real estate | 2026 |
| Norfolk Run Free Ltd | Arts & recreation | 2022 |
| Norfolk Seaside Escapes Ltd | Hospitality | 2026 |
| Norfolk Skin Clinic Limited | Health & social care | 2025 |
| Norfolk Snagging Services Ltd | Construction | 2024 |
| Norfolk Tank Cleaning & Transport Limited | Administrative & support | 2008 |
| Norfolk Trade Kitchens Ltd | Wholesale & retail | 2022 |
| Norman Sprunt Safety Services Limited | Administrative & support | 2006 |
| North Denes Airfield (Holdings) Limited | Construction | 2022 |
| North Gate Executive Search Limited | Administrative & support | 2006 |
| North Norfolk Grab and Aggregates Limited | Extraterritorial | 2024 |
| North Sea Fisheries Limited | Agriculture & fishing | 1991 |
| North Sea Fishermen's Organisation Limited | Other services | 1993 |
| North Sea OIL and GAS Services Ltd | Professional & scientific | 2018 |
| Northgate Memorials Ltd | Manufacturing | 2025 |
| Northold Limited | Financial services | 2006 |
| Norton Plumbing & Heating Ltd | Construction | 2025 |
| Norwich Livestock Market Limited | Wholesale & retail | 2002 |
| NOT Everything Sucks CIC | Health & social care | 2026 |
| Noud Lingerie Ltd | Wholesale & retail | 2023 |
| Novella Models Ltd | Professional & scientific | 2025 |
| NP Periodontics Limited | Health & social care | 2022 |
| NPG Invest Ltd | Financial services | 2026 |
| NR & S Property Ltd | Construction | 2024 |
| NR Marine Services Ltd | Administrative & support | 2019 |
| NR1 Creatives Limited | Arts & recreation | 2003 |
| NR7 Investments Ltd | Financial services | 2020 |
| Nrfk.Studio Ltd | Wholesale & retail | 2022 |
| Nrutilities Limited | Information & communication | 2023 |
| NRW Access Ltd | Manufacturing | 2026 |
| NS Dispensing Ltd | Wholesale & retail | 2023 |
| NS Ormesby Limited | Hospitality | 2026 |
| Nsic Ltd | Mining & quarrying | 2014 |
| NTS Norwich Limited | Transport & logistics | 2013 |
| NTT Services Limited | Professional & scientific | 2025 |
| NUE Web Ltd | Information & communication | 2025 |
| Number 1 Bar and Kitchen Ltd | Hospitality | 2015 |
| Nwes Property Services Limited | Administrative & support | 2005 |
| NY Car & Commercials Limited | Wholesale & retail | 2024 |
| NY Commercial Vehicles Limited | Wholesale & retail | 2026 |
| O'Rourke Offshore Services Limited | Professional & scientific | 2012 |
| O.W Plumbing & Heating Limited | Construction | 2021 |
| Oak House Consultants Limited | Professional & scientific | 1999 |
| Oak Park Farm (Burgh Castle) Limited | Agriculture & fishing | 2019 |
| Oakauri 2021 Ltd | Real estate | 2015 |
| Oakauri Ltd | Households | 2021 |
| Oakes Garland Solutions Limited | Manufacturing | 2020 |
| Oaks Carpentry Contractors Limited | Construction | 2009 |
| Oakville AP Limited | Real estate | 2021 |
| Oakville Homes Limited | Construction | 2004 |
| Oakville Quays Limited | Real estate | 2013 |
| Oakville TP Limited | Real estate | 2023 |
| Oakville Warehousing Limited | Real estate | 2013 |
| Oasis Amusements (Hemsby) Limited | Arts & recreation | 2013 |
| Oasis Coastal Developments Ltd | Extraterritorial | 2024 |
| OAT Investments | Financial services | 2020 |
| Objective Capital Research Limited | Information & communication | 2023 |
| OBS Fibre Limited | Construction | 2026 |
| Obsidianenergy Limited | Manufacturing | 2026 |
| Ocean Cabs (Anglia) Limited | Transport & logistics | 2014 |
| Ocean Guard IT Ltd | Information & communication | 2026 |
| Ocean Supply Ltd | Wholesale & retail | 2024 |
| Oche Addicts Ltd | Wholesale & retail | 2025 |
| Octanest Ltd | Hospitality | 2026 |
| ODE Asset Management Limited | Mining & quarrying | 2018 |
| Odp-Kjs Ltd | Health & social care | 2025 |
| OEG Energy Group Limited | Financial services | 2022 |
| OEG Finance PLC | Financial services | 2024 |
| OEG Global Limited | Financial services | 2012 |