| MJ Motors (NE) Limited | Wholesale & retail | 2017 |
| MKW Auto Electrics Ltd | Wholesale & retail | 2026 |
| MLC Properties NE Ltd | Real estate | 2023 |
| MO Event Furniture Limited | Wholesale & retail | 2016 |
| Modern Precision Engineering Limited | Professional & scientific | 2021 |
| Mono Store Global Ltd | Wholesale & retail | 2025 |
| Morella Properties Ltd | Real estate | 2024 |
| Moto-Tec MOT Centre Limited | Wholesale & retail | 2015 |
| Move Well With Matthew Ltd | Education | 2024 |
| Movematic TSL Limited | Transport & logistics | 2025 |
| MPL Engineering Consultancy Limited | Professional & scientific | 2012 |
| Mpweee Ltd | Other services | 2025 |
| MR Roofer Ltd | Construction | 2024 |
| MR. Yoichi Limited | Information & communication | 2009 |
| Mrfather Ltd | Wholesale & retail | 2025 |
| Muan Store Ltd | Wholesale & retail | 2025 |
| Multibond Solutions Group Limited | Extraterritorial | 2017 |
| Multibond Solutions Limited | Wholesale & retail | 2000 |
| Mundomnia Ltd. | Professional & scientific | 2018 |
| Muslu Trading Ltd | Wholesale & retail | 2025 |
| Mustang Property Solutions Ltd | Real estate | 2026 |
| MW Building Services NE Ltd | Construction | 2026 |
| My Landscaper Ltd | Professional & scientific | 2026 |
| Nahpharm Ltd | Wholesale & retail | 2021 |
| Namaste Spennymoor Limited | Hospitality | 2023 |
| Nautilus Solutions Limited | Professional & scientific | 1998 |
| Navia Trade Ltd | Wholesale & retail | 2026 |
| Nazca&Co Ltd | Wholesale & retail | 2025 |
| NCH Training and Education Limited | Education | 2025 |
| NCS Enterprises Limited | Arts & recreation | 2011 |
| NE1 Property Group Ltd | Real estate | 2016 |
| Nealons Plastering Services Ltd | Construction | 2024 |
| Nectury Ltd | Wholesale & retail | 2026 |
| Neil Bage Kitchens & Bedrooms Ltd | Construction | 2022 |
| Nephew Media (England) Limited | Information & communication | 2014 |
| New Outcomes Ltd. | Administrative & support | 2016 |
| Newarcuk Ltd | Manufacturing | 2024 |
| Newport Generations Limited | Financial services | 2020 |
| Nexaro Trading Ltd | Wholesale & retail | 2026 |
| Niamos Industries Limited | Professional & scientific | 2025 |
| Nicholson Performance Ltd | Wholesale & retail | 2025 |
| NO Ordinary Estates (Access) Ltd | Real estate | 2018 |
| NO Ordinary Estates (Thinford) Limited | Real estate | 2017 |
| NO Ordinary Estates Limited | Construction | 2006 |
| NO Ordinary Property Ltd | Real estate | 2018 |
| Nordex Store Ltd | Wholesale & retail | 2026 |
| North East Contracting Ltd | Professional & scientific | 2023 |
| North East MOT Service Centre Limited | Wholesale & retail | 2022 |
| North East Safety Netting Limited | Construction | 2017 |
| North East Spraggs MOT & Autocare Limited | Wholesale & retail | 2026 |
| North Eastern Events Limited | Arts & recreation | 2026 |
| Northcrest Trading Ltd | Wholesale & retail | 2026 |
| Northern Care Training Limited | Education | 2004 |
| Northern Transport UK Ltd | Transport & logistics | 2023 |
| Northern Window Cleaning Ltd | Administrative & support | 2024 |
| Northgard Properties Limited | Real estate | 2025 |
| NOT More Golf Limited | Extraterritorial | 2024 |
| Notw Record Fairs Limited | Wholesale & retail | 2023 |
| Nova Consilia Consultancy Ltd | Professional & scientific | 2018 |
| Novacraft Trade Ltd | Wholesale & retail | 2026 |
| Nucud Ltd | Wholesale & retail | 2025 |
| Nunu Trade Ltd | Wholesale & retail | 2026 |
| Nutmeg & Sprout Wraparound Care Limited | Health & social care | 2025 |
| Nuveart Limited | Wholesale & retail | 2025 |
| NVM (4M) Ltd | Manufacturing | 2020 |
| O'Hehir School of Irish Dance C.I.C. | Arts & recreation | 2017 |
| O'Keeffe Enterprises Ltd | Real estate | 2019 |
| Oak Vale Genetics Ltd | Agriculture & fishing | 2023 |
| Oflaz Ltd | Wholesale & retail | 2026 |
| Oliver Twists Threads Ltd | Manufacturing | 2003 |
| OMD Ward Solutions Limited | Construction | 2024 |
| Onflo Limited | Construction | 2020 |
| Onno Trade Ltd | Wholesale & retail | 2026 |
| Opmtransport Ltd | Transport & logistics | 2026 |
| Orakk Ltd | Wholesale & retail | 2025 |
| Orhan Properties Ltd | Real estate | 2025 |
| Orvella Trade Ltd | Wholesale & retail | 2026 |
| Orventa Ltd | Wholesale & retail | 2026 |
| Oryn Retail Ltd | Wholesale & retail | 2026 |
| P&B Utilities Ltd | Construction | 2023 |
| Paag Brothers Ltd | Wholesale & retail | 2025 |
| Padel League Network Ltd | Arts & recreation | 2025 |
| Paint Monster Ltd | Wholesale & retail | 2022 |
| Paisley Richardson O Golf Limited | Education | 2024 |
| Palatine Consulting Ltd | Professional & scientific | 2012 |
| Pamper Retreats Limited | Hospitality | 2018 |
| Pamur Co Ltd | Real estate | 2023 |
| Paramount Plates Ltd | Wholesale & retail | 2025 |
| Party GEM NE Limited | Arts & recreation | 2017 |
| Patel Path Services Limited | Real estate | 2017 |
| Pauglobal Ltd | Wholesale & retail | 2025 |
| Paul Moses Joinery Limited | Construction | 2013 |
| Paving Supplies Northern Limited | Wholesale & retail | 2024 |
| Paving Supplies Online Limited | Wholesale & retail | 2024 |
| Paving the Way (NE) Limited | Administrative & support | 2020 |
| PAW PIT Stop Ltd | Other services | 2026 |
| PB Construction Ltd | Construction | 2025 |
| Peach Lettings Limited | Real estate | 2021 |
| Peach Tornado Ltd | Wholesale & retail | 2022 |
| Pedro's NE Ltd | Hospitality | 2019 |