| Nellis TM Ltd | Construction | 2022 |
| Nelson's (Swarland) Limited | Hospitality | 2015 |
| Neonsquare Property Management Company Limited | Households | 1991 |
| Neothesia Limited | Health & social care | 2015 |
| Nest Away Cottages Ltd | Hospitality | 2025 |
| Netherton Southside Management Company Limited | Households | 2007 |
| Netherwitton Heating Company Limited | Manufacturing | 2011 |
| New State Design Ltd | Professional & scientific | 2020 |
| Newminster Community Interest Company | Arts & recreation | 2026 |
| Newstead & Co Limited | Extraterritorial | 2010 |
| Newton Hall Estate Management Company Limited | Households | 2010 |
| Newton Red House (Management) Company Limited | Real estate | 2003 |
| NGL Construction Ltd | Construction | 2020 |
| Niall Molloy Investments Ltd | Real estate | 2022 |
| Nice Survey Ltd | Professional & scientific | 2018 |
| Nightingale Nannies Worldwide Limited | Health & social care | 2019 |
| Njgautos Ltd | Wholesale & retail | 2025 |
| NJR Willow Ltd | Extraterritorial | 2011 |
| Nocca Consulting Ltd | Professional & scientific | 2019 |
| Nomi Hexham Ltd | Hospitality | 2025 |
| NON Intrusive Inspection Consultancy Ltd | Professional & scientific | 2015 |
| Nor'East Marine Ltd | Professional & scientific | 2025 |
| Nortech Garage Doors Limited | Other services | 2000 |
| North Coast Lettings Limited | Real estate | 2026 |
| North East Accountancy Solutions Limited | Professional & scientific | 2017 |
| North East Aero Engineering Limited | Professional & scientific | 2024 |
| North East Airfield Management Limited | Transport & logistics | 2024 |
| North East Aviation Services Limited | Administrative & support | 2024 |
| North East Aviation Training Limited | Administrative & support | 2024 |
| North East Cellar Supplies Limited | Wholesale & retail | 2005 |
| North East Drinks Supplies Ltd | Wholesale & retail | 2010 |
| North East Dwellings Ltd | Real estate | 2023 |
| North East Equestrian Ltd | Agriculture & fishing | 2025 |
| North East Equity Release Ltd | Extraterritorial | 2020 |
| North East Interiors Limited | Other services | 2016 |
| North East PM Ltd | Professional & scientific | 2026 |
| North East Property and Investments Limited | Real estate | 2007 |
| North East Recruitment Limited | Administrative & support | 2023 |
| North East Water Equipment Limited | Water & waste | 2010 |
| North Renovations Ltd | Real estate | 2025 |
| North Saltwick Farm Management Company Limited | Households | 2004 |
| North Sea Shoreline Stays Ltd | Hospitality | 2023 |
| North Town Miniatures Ltd | Arts & recreation | 2020 |
| Northern Adventures Ltd | Administrative & support | 2022 |
| Northern ARC Nursery Limited | Agriculture & fishing | 2023 |
| Northern Bean Coffee Company Ltd | Manufacturing | 2022 |
| Northern Bespoke Visuals Ltd | Professional & scientific | 2025 |
| Northern Building Solutions Limited | Construction | 2025 |
| Northern Construction Ltd | Real estate | 2024 |
| Northern Contractors Ltd. | Agriculture & fishing | 2014 |
| Northern Glow Ltd | Wholesale & retail | 2025 |
| Northern Holistics Ltd | Other services | 2024 |
| Northern Hospitalities Ltd | Hospitality | 2024 |
| Northern Impact Legal Ltd. | Professional & scientific | 2019 |
| Northern Prop Hire Limited | Administrative & support | 2004 |
| Northern Psychology Services Ltd | Administrative & support | 2015 |
| Northern Scaffold Limited | Construction | 2025 |
| Northern Stars Football Ltd | Professional & scientific | 2024 |
| Northern Woodcraft Ltd | Education | 2024 |
| Northernsc Limited | Wholesale & retail | 2026 |
| Northernstar Bookkeeping Ltd | Professional & scientific | 2026 |
| Northfield Estate (NE) Limited | Professional & scientific | 2024 |
| Northside Homes Limited | Real estate | 2016 |
| Northstage Events Ltd. | Arts & recreation | 2022 |
| Northumberland (Longframlington) Ltd | Construction | 2020 |
| Northumberland Accountants and Tax Advisers Ltd | Professional & scientific | 2009 |
| Northumberland Arms Ltd | Hospitality | 2025 |
| Northumberland Castle and Country Lodgings Ltd | Hospitality | 2013 |
| Northumberland Coast Cottages Limited | Hospitality | 2021 |
| Northumberland Coastal Concierge Ltd | Administrative & support | 2024 |
| Northumberland Community Enterprise Limited | Other services | 2008 |
| Northumberland Construction Solutions Ltd | Construction | 2025 |
| Northumberland County Blind Association | Health & social care | 2002 |
| Northumberland Crematorium Limited | Other services | 2020 |
| Northumberland Escapes Limited | Hospitality | 2020 |
| Northumberland Facilities Management Ltd | Real estate | 2023 |
| Northumberland Free Range Ltd | Agriculture & fishing | 2025 |
| Northumberland Futsal Ltd | Arts & recreation | 2014 |
| Northumberland Gardens (Morpeth) Management Company Limited | Households | 2019 |
| Northumberland Gifts Ltd | Manufacturing | 2008 |
| Northumberland Grill House Ltd | Hospitality | 2025 |
| Northumberland Group Ltd | Construction | 2020 |
| Northumberland Haunted Museum CIC | Wholesale & retail | 2026 |
| Northumberland Homes Ltd | Real estate | 2024 |
| Northumberland Hot TUB Lodge Ltd | Hospitality | 2020 |
| Northumberland Kitchen and Bedroom Company Ltd | Wholesale & retail | 2025 |
| Northumberland Lets Ltd | Real estate | 2022 |
| Northumberland Lodge Retreats Ltd | Hospitality | 2021 |
| Northumberland Luxury Limited | Real estate | 2020 |
| Northumberland Medicines Limited | Health & social care | 2009 |
| Northumberland OIL & GAS Planning Services Ltd | Professional & scientific | 2026 |
| Northumberland Properties & Lodges Ltd | Hospitality | 2025 |
| Northumberland Property Management Limited | Real estate | 2019 |
| Northumberland Safety Solutions Ltd | Professional & scientific | 2024 |
| Northumberland Self Catering Cottages Ltd | Hospitality | 2013 |
| Northumberland Specialist Building Services Ltd | Construction | 2015 |
| Northumberland Stays NE Ltd | Professional & scientific | 2018 |
| Northumberland ZOO Ltd | Arts & recreation | 2018 |
| Northumberlets Limited | Hospitality | 2018 |
| Northumbria Dental Care Limited | Health & social care | 2006 |