| New Shanghai Palace Ltd | Hospitality | 2024 |
| New Sundial PUB Ltd | Hospitality | 2025 |
| New TPA Limited | Wholesale & retail | 2020 |
| Newcastle Pharma Ltd | Health & social care | 2024 |
| Newco L108 Limited | Professional & scientific | 2025 |
| Newtonnes Ltd | Professional & scientific | 2024 |
| Next GEN BIM Ltd | Construction | 2025 |
| Nexus Group Teesside Ltd | Transport & logistics | 2019 |
| NFT Training Ltd | Professional & scientific | 2017 |
| NG Racing Limited | Arts & recreation | 2019 |
| Nicander Limited | Information & communication | 2007 |
| Nice HAT Holdings Ltd | Financial services | 2024 |
| Nice HAT Residential Ltd | Real estate | 2024 |
| Nichola Stott Limited | Information & communication | 2024 |
| Nicomachea Limited | Information & communication | 2026 |
| Nicwill Ltd | Real estate | 2024 |
| Niehorster Bess Ltd | Real estate | 2024 |
| Niehorster Family Holdings Ltd | Real estate | 2021 |
| Nigel Brocklehurst Rental Partnership LLP | | 2019 |
| Nightingale Yorkshire Ltd | Health & social care | 2016 |
| Nilu and Vijay Shaunak LLP | | 2019 |
| Nimbuzz Ltd | Wholesale & retail | 2025 |
| NJB Systems Limited | Professional & scientific | 2013 |
| NKL Services Ltd | Transport & logistics | 2017 |
| NO Limit Security Ltd | Administrative & support | 2024 |
| NO Suga Ltd | Hospitality | 2025 |
| NO.26 Property Management Limited | Real estate | 2024 |
| Nook & Bear Ltd | Wholesale & retail | 2023 |
| Normans of Billingham Limited | Wholesale & retail | 1988 |
| North East Care Homes HR Limited | Administrative & support | 2014 |
| North East General Practice Limited | Health & social care | 2023 |
| North East Leyland DAF Limited | Wholesale & retail | 1973 |
| North East Point of Sale Ltd | Information & communication | 2024 |
| North East Tanktech Limited | Professional & scientific | 2001 |
| North East Truck & Van (Immingham) Limited | Wholesale & retail | 1996 |
| North East Truck & Van Holdings Limited | Financial services | 2014 |
| North East Truck & Van Limited | Wholesale & retail | 1993 |
| North-East Medical Services Ltd | Health & social care | 2024 |
| Northcore Property Services Ltd | Administrative & support | 2026 |
| Northeast Vascular Care Limited | Health & social care | 2016 |
| Northern Circumcision Clinic Limited | Health & social care | 2012 |
| Northern Education Solutions Limited | Education | 2026 |
| Northern Gynaecology Services Ltd | Health & social care | 2024 |
| Northern Heritage Engineering Limited | Manufacturing | 2024 |
| Northern Ltd | Financial services | 2004 |
| Northern Star Enterprises Limited | Health & social care | 2003 |
| Northern Surgery Limited | Health & social care | 2014 |
| Northfield Property Partners Limited | Real estate | 2025 |
| Northgate Estates (NE) Ltd | Real estate | 2016 |
| Norton Serviced Apartments Limited | Real estate | 2022 |
| NOT in USE CJP Ltd | Administrative & support | 2016 |
| NOT in USE JSA PAY Limited | Administrative & support | 2019 |
| Novo-Height Partnership LLP | | 2023 |
| Novora Real Estate Ltd | Real estate | 2025 |
| Novus Wealth Holdings Ltd | Financial services | 2015 |
| Novus Wealth Management Ltd | Financial services | 2015 |
| NP Hospitality Ltd | Hospitality | 2024 |
| NRS Medical Ltd | Health & social care | 2025 |
| NTB Engineering Ltd | Construction | 2025 |
| NWA Social and Market Research Limited | Professional & scientific | 2003 |
| Nymack Ltd | Administrative & support | 2013 |
| Nymas Group Limited | Manufacturing | 2024 |
| O&B Offshore Consultancy and Management Ltd | Professional & scientific | 2013 |
| O&V Ltd | Real estate | 2024 |
| O'Donnell Property (NE) Ltd | Construction | 2016 |
| O'Dowd NDT Ltd | Professional & scientific | 2026 |
| O'Grady Russell Ltd | Real estate | 2017 |
| O'Grady Russell Partnership LLP | | 2017 |
| Oak Edge Joinery + Construction Ltd | Construction | 2026 |
| Oak Property's Ltd | Real estate | 2024 |
| Oakdale (Contracts) Limited | Manufacturing | 1996 |
| Oaklands Medical Limited | Health & social care | 2014 |
| Oakmont Living Ltd | Real estate | 2026 |
| Obilloyds Limited | Construction | 2025 |
| Oceanic Red Ltd | Wholesale & retail | 2018 |
| OCG Accountants Ltd | Professional & scientific | 2018 |
| OCS Accountants (North East) Ltd | Professional & scientific | 2023 |
| OCS Accountants Ltd | Professional & scientific | 2024 |
| Oculum Limited | Administrative & support | 2021 |
| Odoriko Ltd | Real estate | 2021 |
| Odyssey Personal Training Ltd | Arts & recreation | 2020 |
| Offspring Properties Ltd | Real estate | 2020 |
| OG Personnel Admin Ltd | Administrative & support | 2021 |
| OG Personnel Ltd | Administrative & support | 2021 |
| OG Realisations 2026 Limited | Wholesale & retail | 2019 |
| Oggbab Torr Ltd | Professional & scientific | 2026 |
| OH & H Ltd | Administrative & support | 2009 |
| OK Safety Ltd | Professional & scientific | 2024 |
| OKO Solid Fuels Ltd | Manufacturing | 2022 |
| Olben Motor Centre Limited | Wholesale & retail | 2024 |
| Olivia Warrener Accountancy Ltd | Professional & scientific | 2018 |
| Omnis Education Consultancy Ltd | Education | 2024 |
| Omorfia Tech Innovations Ltd | Manufacturing | 2024 |
| Oncology North Ltd | Health & social care | 2025 |
| One Coat Solutions Ltd | Construction | 2025 |
| One Consultancy Group Ltd | Financial services | 2019 |
| One Excellence Multi Academy Trust | Education | 2017 |
| One Two Business Solutions Limited | Financial services | 2024 |
| Onkar Real Estate Ltd | Real estate | 2025 |
| Ontrax Group Limited | Wholesale & retail | 2025 |