| Nicholson Clark Ltd | Professional & scientific | 2015 |
| Nicholson Portnell Limited | Extraterritorial | 2011 |
| Nigel John Photography Ltd | Professional & scientific | 2023 |
| Nigel Price 4 Wheel Drive Ltd | Wholesale & retail | 2012 |
| Nigel Wright Plumbing & Heating Ltd | Construction | 2010 |
| Nixon Groundworks Limited | Construction | 2024 |
| NJ Mason Ltd | Professional & scientific | 2020 |
| Njsc Limited | Professional & scientific | 2002 |
| NMW Education Ltd | Education | 2022 |
| NO Limits Dance Studio Limited | Arts & recreation | 2017 |
| NO Strings Ltd | Wholesale & retail | 2024 |
| NO. 11 Granville Road Management Company Limited | Hospitality | 1997 |
| Noble EAR Care Ltd | Health & social care | 2024 |
| Noble Roots Limited | Agriculture & fishing | 2025 |
| North East House Building and Renovation Services Limited | Construction | 2018 |
| North East Pharma Limited | Administrative & support | 2020 |
| North East Solar Solutions Limited | Construction | 2011 |
| North East Wellbeing | Education | 2012 |
| North Farm Gunnerton Ltd | Agriculture & fishing | 2022 |
| North Roots Limited | Information & communication | 2026 |
| North Tyne & Redesdale Community Partnership | Other services | 2010 |
| North Tyne and Redesdale Agricultural Society EST 1842 | Extraterritorial | 2015 |
| North Tyne Fencing Ltd | Construction | 2018 |
| North Tyne Game & Sporting Limited | Agriculture & fishing | 2018 |
| North Tyne Game Birds Limited | Agriculture & fishing | 2021 |
| North Tyne Truck Run Limited | Administrative & support | 2024 |
| Northeast Veterinary Imaging Limited | Professional & scientific | 2013 |
| Northern County Finance Limited | Administrative & support | 2024 |
| Northern County Motor & Asset Finance Limited | Financial services | 2011 |
| Northern Edge Strategy Limited | Professional & scientific | 2025 |
| Northern Maintenance Ltd | Professional & scientific | 2024 |
| Northern Medical Practitioners Limited | Health & social care | 2024 |
| Northern Rheumatology Ltd | Health & social care | 2021 |
| Northern Sprinklers and Site Services Limited | Professional & scientific | 2018 |
| Northumberland Adventure Centre Limited | Hospitality | 2009 |
| Northumberland Dog Hotel Limited | Agriculture & fishing | 2024 |
| Northumberland Domestic Abuse Services Ltd | Health & social care | 2007 |
| Northumberland National Park Foundation | Administrative & support | 2014 |
| Northumberland Pram Centre Limited | Wholesale & retail | 2026 |
| Northumberland Rugby Union Referees Limited | Arts & recreation | 2017 |
| Northumbria Calvert Trust | Arts & recreation | 1981 |
| Northumbria Game Ltd. | Manufacturing | 2019 |
| Northumbria Pest Control Ltd | Other services | 2010 |
| Northumbrian Botanicals Limited | Manufacturing | 2018 |
| Northumbrian Holiday Cottages Ltd | Real estate | 2020 |
| Northumbrian Pantry Limited | Wholesale & retail | 2019 |
| Northumbrian Pointing LLP | | 2025 |
| Northumbrian Property Services Group Limited | Construction | 2015 |
| Northumbrian Windows Ltd | Wholesale & retail | 2017 |
| Northwood Agri Contracting Ltd | Administrative & support | 2022 |
| Norwest Properties Ltd | Real estate | 2014 |
| NOT Even Limited | Wholesale & retail | 2025 |
| November 26 Limited | Real estate | 2014 |
| Npsweep Ltd | Administrative & support | 2020 |
| Nuliving Homecare Limited | Health & social care | 2026 |
| Number Four Beaumont Limited | Hospitality | 2024 |
| O'Donnell & Reed Groundwork & Landscaping Limited | Administrative & support | 2020 |
| Oakwood Bespoke Building and Joinery Ltd | Construction | 2018 |
| Ochiltree Bespoke Joinery Ltd | Manufacturing | 2015 |
| OCM Business Solutions Ltd | Professional & scientific | 2014 |
| Offshore Projects Consultants Ltd | Professional & scientific | 2020 |
| OH LA LA Hexham Ltd | Wholesale & retail | 2025 |
| Old Works Ford Ltd | Manufacturing | 2017 |
| Olivers Financial Ltd | Professional & scientific | 2025 |
| Ollie Morton Tree Care Ltd | Agriculture & fishing | 2019 |
| One Digital Image Limited | Information & communication | 2012 |
| One&One Property Ltd | Real estate | 2020 |
| One&One Property Trading Ltd | Real estate | 2026 |
| Ongoing Limited | Professional & scientific | 2019 |
| Ontos Games Limited | Manufacturing | 2023 |
| Onya Wellness Ltd | Other services | 2025 |
| OPINION42 Limited | Professional & scientific | 2025 |
| Optima Coffee Limited | Wholesale & retail | 2006 |
| Optimise Consultancy Services Limited | Professional & scientific | 2023 |
| Orion Investments (NE) Ltd | Extraterritorial | 2023 |
| Oshanthii Ltd | Hospitality | 2026 |
| Osman Property Limited | Real estate | 2013 |
| Otter Chaos Ltd | Hospitality | 2023 |
| Outkast Hospitality Limited | Hospitality | 2025 |
| Outstanding Lettings and Design Limited | Hospitality | 2012 |
| Ovidian Ltd | Information & communication | 2016 |
| OWA Digital Ltd. | Information & communication | 1995 |
| Oxley Farming Limited | Agriculture & fishing | 2022 |
| P Findlay Contracting Limited | Agriculture & fishing | 2024 |
| P1L1 Limited | Professional & scientific | 1999 |
| Paediatric Nephrology Legal Expertise Ltd | Health & social care | 2024 |
| Palumbus Pursuits Limited | Other services | 2016 |
| Parkhouse Lodges Limited | Education | 2013 |
| Party Sense Limited | Arts & recreation | 2025 |
| Patricia J Arnold & Co Ltd | Professional & scientific | 2009 |
| Paul Britten Roofing Ltd | Construction | 2026 |
| Paul Marazzi Ltd | Arts & recreation | 2019 |
| Pavi Convenience UK Ltd | Wholesale & retail | 2021 |
| PCC Systems (UK) Limited | Information & communication | 2002 |
| PDL Solutions (Europe) Limited | Professional & scientific | 2001 |
| Peace of Mind Homes Ltd | Construction | 2024 |
| Peacock Robotics Limited | Professional & scientific | 2026 |
| Peart Arenas Limited | Construction | 2003 |
| Peas and Libertea Limited | Hospitality | 2024 |
| Pennine Way Homes Ltd | Real estate | 2026 |