| Mingo Beauty Room Ltd | Other services | 2023 |
| Minhoco 84 Limited | Financial services | 2023 |
| Minttec Ltd | Information & communication | 2010 |
| Mirzautocar Ltd. | Wholesale & retail | 2014 |
| MJL Bricklaying Ltd | Construction | 2023 |
| MJL Services Ltd. | Water & waste | 2015 |
| MJW Steel Ltd | Construction | 2023 |
| MK Holdings Newcastle Ltd | Real estate | 2024 |
| MMB Leisure Ltd | Hospitality | 2025 |
| MMD Limited | Education | 2003 |
| Mo-Squared UK Properties Limited | Real estate | 2022 |
| Moisture Mend Damp Surveyors Ltd | Construction | 2025 |
| Monkseaton Hire Limited | Administrative & support | 2012 |
| Monkton Dene View Management Scheme Ltd | Real estate | 2016 |
| Morning Cloud Limited | Hospitality | 2026 |
| Morpheus Integrated Technologies Limited | Information & communication | 1992 |
| Morvareed Cleaning Ltd | Manufacturing | 2023 |
| Motorfix NE Ltd | Wholesale & retail | 2024 |
| Mountain Cubed Ltd | Wholesale & retail | 2023 |
| Move IT Studios Community Interest Company | Arts & recreation | 2014 |
| Moving Art Management Limited | Arts & recreation | 2015 |
| Moyo Care Group Ltd | Health & social care | 2025 |
| MR DOI Ltd | Hospitality | 2024 |
| MR Munchey Ltd | Hospitality | 2024 |
| MS Building Work Limited | Construction | 2025 |
| MS Pipefitting Services Ltd | Construction | 2016 |
| MSA Windows Ltd | Manufacturing | 2019 |
| MTN Construction Ltd | Construction | 2024 |
| Mukhtiar Sharry Limited | Transport & logistics | 2025 |
| Music Hands Ltd | Education | 2014 |
| Mycoverplan Insurance Services Ltd | Financial services | 2010 |
| Myfolks Ltd | Other services | 2023 |
| Mysocialhealth Ltd | Other services | 2024 |
| Mythic Limited | Professional & scientific | 2017 |
| Mzberg Ltd | Professional & scientific | 2018 |
| Mzburg Ltd | Professional & scientific | 2025 |
| N & a Civils Ltd | Construction | 2026 |
| N.E Autocentre Ltd | Wholesale & retail | 2024 |
| N.E BRD Ltd | Real estate | 2022 |
| N.E Renovations and Developments Ltd | Construction | 2020 |
| N.T. & Family Limited | Other services | 2015 |
| N.T. Steel Services Ltd | Wholesale & retail | 2005 |
| Natalia’S Butcher & Eatery Ltd | Manufacturing | 2026 |
| Nationwide Forklifts Limited | Administrative & support | 2011 |
| NC Aesthetics Cosmetic Clinic Ltd | Other services | 2023 |
| NCC Housing Ltd | Hospitality | 2023 |
| NDT Assessment Services Ltd | Professional & scientific | 2017 |
| NE Gaming Studio Ltd | Information & communication | 2025 |
| NE Home Improvements Ltd | Construction | 2025 |
| NE Online Solutions Ltd | Other services | 2016 |
| NE Steel Ltd | Construction | 2019 |
| NE1WELDARC Ltd | Manufacturing | 2022 |
| Neale Pattison Financial Services Ltd | Financial services | 2025 |
| Necta Holdings Limited | Manufacturing | 2024 |
| Neil & Son's Property Management Limited | Real estate | 2024 |
| Net-Zero Renewable Energy Ltd | Construction | 2022 |
| Network Northumberland Ltd | Information & communication | 2018 |
| Neuronetwork Ltd | Health & social care | 2020 |
| New Leaf UK Developments Limited | Construction | 2006 |
| Newcastle Air Conditioning Ltd | Energy | 2023 |
| Newcastle Computer Services Ltd | Other services | 2016 |
| Newcastle Dairy Ltd | Manufacturing | 2025 |
| Newcastle Fighters Academy CIC | Education | 2025 |
| Newcastle Fighters C.I.C. | Education | 2019 |
| Newcastle Financial Advisers Limited | Financial services | 2002 |
| Newcastle Flower Wall Company Ltd | Wholesale & retail | 2018 |
| Newcastle International Culture and Education Company Limited | Professional & scientific | 2015 |
| Newcastle Play Limited | Professional & scientific | 2013 |
| Newcastle Property Company Limited | Real estate | 2006 |
| Newcastle Strategic Solutions Limited | Administrative & support | 2002 |
| Newcastle Taekwondo CIC | Education | 2020 |
| Newgate Air Systems (UK) Limited | Energy | 2003 |
| Nextgen Property NE Ltd | Construction | 2026 |
| NIC HIT Ltd | Wholesale & retail | 2023 |
| Nirvana Europe Limited | Administrative & support | 1999 |
| Nirvana World Limited | Administrative & support | 2008 |
| NL Foods Ltd | Hospitality | 2016 |
| NLW Fitness Limited | Arts & recreation | 2024 |
| NMS Commercial Services Limited | Financial services | 2001 |
| NMS Financial Ltd | Financial services | 2010 |
| Noble Convenience Store Ltd | Wholesale & retail | 2019 |
| Norham Holdings Group Limited | Real estate | 2007 |
| North Consulting Group Limited | Professional & scientific | 2016 |
| North East Air Conditioning Group Limited | Energy | 2025 |
| North East Athletic Development Limited | Arts & recreation | 2020 |
| North East Balustrades Ltd | Manufacturing | 2022 |
| North East Builders Ltd | Construction | 2026 |
| North East Building Renovation & Development Ltd | Construction | 2015 |
| North East Family Fitness CIC | Health & social care | 2023 |
| North East Ground Rents Limited | Real estate | 2015 |
| North East Landlords Ltd | Real estate | 2025 |
| North East Living Ltd | Real estate | 2026 |
| North East Pipeline Solutions Ltd | Manufacturing | 2018 |
| North East Plumbing Repairs Ltd | Construction | 2022 |
| North East Radio Communications Limited | Manufacturing | 1980 |
| North East Supported Tenancies Limited | Hospitality | 2018 |
| North East Traffic Data Collection Ltd | Professional & scientific | 2013 |
| North East Venture Properties Ltd | Real estate | 2020 |
| North Moon Ltd | Real estate | 2023 |
| North Point Construction RM Ltd | Construction | 2026 |