| Next Day Solutions Ltd | Transport & logistics | 2026 |
| Next GEN Homes NE Ltd | Construction | 2023 |
| Nibble & Graze Ltd | Hospitality | 2025 |
| Nicholsons Property Investment Limited | Real estate | 2019 |
| Nigel Shield Plant & Haulage Limited | Transport & logistics | 2023 |
| Nixion Ltd | Administrative & support | 1981 |
| NJS Groundworks ( North East ) Ltd | Construction | 2023 |
| NKS Properties and Investments Limited | Real estate | 2026 |
| NLB Developments Ltd | Construction | 2017 |
| NLB Developments NE Ltd | Construction | 2019 |
| NM Rail Limited | Construction | 2015 |
| NMB Partitions Limited | Construction | 2001 |
| Noble's Bingo DL14 Limited | Arts & recreation | 2025 |
| Nobleseals Ltd | Wholesale & retail | 2025 |
| Noon Living Ltd | Wholesale & retail | 2021 |
| Nord Estates Ltd | Construction | 2019 |
| North Bondgate Ltd | Hospitality | 2026 |
| North Country Wood Fuels Limited | Agriculture & fishing | 2009 |
| North East Containers Ltd | Wholesale & retail | 2026 |
| North East Doctors Limited | Health & social care | 2022 |
| North East Kitchen Solutions Ltd | Manufacturing | 2014 |
| North East Leisure Group Ltd | Hospitality | 2025 |
| North Fleet and Plant Limited | Wholesale & retail | 2025 |
| North Stockton PCN Limited | Health & social care | 2023 |
| Northern Directories Limited | Professional & scientific | 2020 |
| Northern Lithium (Eastgate) Limited | Professional & scientific | 2024 |
| Northern Monkeys Events Limited | Professional & scientific | 2014 |
| Northern Ridge Ltd | Agriculture & fishing | 2026 |
| Northern Workspace Ltd | Real estate | 2021 |
| Northgate Systems (N.E.) Limited | Information & communication | 2003 |
| Northpeak Access Ltd | Construction | 2025 |
| Northpro Carpet Cleaning Ltd | Administrative & support | 2026 |
| Northstone Groundworks Ltd | Construction | 2026 |
| Northstone Roofing & Building Ltd | Construction | 2025 |
| Northumberland Stone Limited | Mining & quarrying | 1998 |
| Northumbria Day Nurseries Ltd | Education | 2022 |
| Northumbria Properties Ltd | Real estate | 2022 |
| Novaira Filtration Limited | Other services | 2024 |
| Novodec Limited | Construction | 2003 |
| NR Catering Ltd | Hospitality | 2025 |
| NRC (ST Helen) Ltd | Hospitality | 2016 |
| NRT Design Services Ltd | Construction | 2025 |
| NS Academy Ltd | Education | 2016 |
| Nurro Ltd | Information & communication | 2019 |
| NYX Real Estate Ltd | Real estate | 2023 |
| NZ Eco Electric Ltd | Professional & scientific | 2010 |
| Oakleaf Community Projects CIC | Wholesale & retail | 2023 |
| Oakley Service Station Limited | Wholesale & retail | 1999 |
| Oakroyd Management Company Limited | Households | 2018 |
| Oasis West Investments Limited | Real estate | 2017 |
| OBB Logistics Limited | Transport & logistics | 2021 |
| Occupational Health and Wellbeing Ltd | Health & social care | 2014 |
| Ococo Ltd | Professional & scientific | 2020 |
| OFC Electrical Ltd | Construction | 2022 |
| Officestor Installations Limited | Administrative & support | 2008 |
| OH My Dog North East Limited | Other services | 2021 |
| Old Foundry Self Storage Limited | Transport & logistics | 2006 |
| Olive Grove Contracting Limited | Construction | 2022 |
| OLLYJACK17 Limited | Other services | 2011 |
| Omax Land Consultancy Ltd | Professional & scientific | 2023 |
| ON NET Communications Limited | Extraterritorial | 2005 |
| ONE16 Properties Ltd | Real estate | 2024 |
| Open Arms Ltd | Education | 2017 |
| Optimalpath Consulting Limited | Information & communication | 2015 |
| Orange Universal Services Limited | Health & social care | 2014 |
| Orbit Flow Digital Ltd | Information & communication | 2025 |
| Orchard Park (Ulleskelf) Management Company Limited | Real estate | 2018 |
| Orkan Transport Ltd | Transport & logistics | 2023 |
| OSC Appliance Repairs Ltd | Manufacturing | 2022 |
| Osys Technology Limited | Information & communication | 1996 |
| Outside Break Limited | Administrative & support | 2005 |
| Oversee (Yarm UK) Limited | Wholesale & retail | 2016 |
| Oversee From UK Limited | Wholesale & retail | 2026 |
| Oxenby Place Management Co Limited | Real estate | 2014 |
| Ozrium Motors Ltd | Wholesale & retail | 2016 |
| P Myers Plastering Contractors Limited | Construction | 2018 |
| P Coates Engineering Ltd | Manufacturing | 2014 |
| P Fallon Stonework Limited | Construction | 2023 |
| P J M Properties Limited | Real estate | 2002 |
| P Moody Building Contracts Limited | Construction | 2022 |
| P Young Developments Limited | Construction | 2005 |
| P.B. Hodgson Limited | Wholesale & retail | 2003 |
| PA Quality Testing Ltd | Professional & scientific | 2011 |
| Pactcab Limited | Financial services | 1988 |
| Padel Arena Ltd | Arts & recreation | 2025 |
| Padlic Ltd | Transport & logistics | 2024 |
| Page 2000 Systems Limited | Information & communication | 1996 |
| Painttechnics North East Limited | Wholesale & retail | 2013 |
| PAL Quantity Surveyors Ltd | Professional & scientific | 2019 |
| Palacegate Management Company Limited | Households | 1993 |
| Panda Imports Limited | Extraterritorial | 2026 |
| Paraglo Holdings Limited | Financial services | 2019 |
| Paraglo Properties Limited | Real estate | 2019 |
| Paraglo Sunbeds Limited | Health & social care | 2019 |
| Paramac Fabrications Ltd | Construction | 2023 |
| Park Head Leisure Ltd | Hospitality | 2008 |
| Park Place (Knaresborough) Management Company Limited | Households | 2019 |
| Parkerfold Ltd | Manufacturing | 2014 |
| Patrick Mcreddie Consulting Engineers Ltd | Extraterritorial | 2024 |
| Pattinson Installations Limited | Construction | 2020 |