| MD79 Electrical Solutions Ltd | Construction | 2024 |
| MDS Bishop Ltd | Wholesale & retail | 2024 |
| Medgp Locums Ltd | Health & social care | 2025 |
| Mediary Limited | Professional & scientific | 2024 |
| Medicals Plus Limited | Health & social care | 2013 |
| Medlife M&M Ltd | Health & social care | 2022 |
| Meear Limited | Professional & scientific | 2018 |
| Megan Woolley Notary Public Ltd | Professional & scientific | 2020 |
| Meikles Solicitors (NE) Limited | Professional & scientific | 2024 |
| Merchantmetals Ltd | Wholesale & retail | 2025 |
| Merissa Campbell Limited | Extraterritorial | 2025 |
| MET Events Limited | Hospitality | 2022 |
| Meticon Ltd | Professional & scientific | 2022 |
| Metrec (Salvage) Limited | Professional & scientific | 1964 |
| MGL Wealth Management Limited | Financial services | 2016 |
| MH Fencing and Gates Limited | Administrative & support | 2014 |
| Mhdlh Ltd | Financial services | 2008 |
| MHS Countryside Management Limited | Administrative & support | 2005 |
| Michael Dowson Construction Ltd | Construction | 2011 |
| Michael Kyle Wealth Management Limited | Financial services | 2020 |
| Micro Business Services Ltd | Real estate | 2025 |
| Midas Property Investment & Consultancy Service Limited | Real estate | 2012 |
| Mighty Warriors Limited | Arts & recreation | 2020 |
| Mike Neesam & SON Limited | Construction | 2011 |
| Milameron Limited | Professional & scientific | 2026 |
| Millennium Decorators Limited | Construction | 2005 |
| Mind Your Business Ltd | Administrative & support | 2026 |
| Mind,Body & Spirit Nurturing Ltd | Agriculture & fishing | 2024 |
| Mini World 8 Ltd | Hospitality | 2022 |
| Minitouch Ltd | Manufacturing | 2012 |
| Mintworks Digital Ltd | Professional & scientific | 2025 |
| Miss Blitz Ltd | Administrative & support | 2025 |
| Mitchell Francis Associates Ltd | Professional & scientific | 2021 |
| Mitchells Grievson Limited | Professional & scientific | 2008 |
| Mitre Joinery & Carpentry Limited | Construction | 2022 |
| Mixrova Ltd | Construction | 2025 |
| MJ Laverick Limited | Professional & scientific | 2021 |
| MJB Medic Limited | Health & social care | 2023 |
| MJM Car Sales Limited | Wholesale & retail | 2019 |
| MJS Locksmiths Ltd | Manufacturing | 2014 |
| MJW Transport Ltd | Transport & logistics | 2025 |
| MK Floor Screeding Ltd | Construction | 2017 |
| ML Hair Studio Ltd | Other services | 2024 |
| ML Windscreens Ltd | Wholesale & retail | 2026 |
| Mmxs Ltd | Construction | 2025 |
| Mohamed Delivery Ltd | Transport & logistics | 2026 |
| Mojo Renewables Ltd | Professional & scientific | 2023 |
| Molltech Ltd | Professional & scientific | 2025 |
| Momentum Development Company NE Limited | Real estate | 2016 |
| Monstar Wear Ltd | Wholesale & retail | 2019 |
| Montwell Ltd | Real estate | 2016 |
| Moor's Head's Engineering Service's Limited | Professional & scientific | 2018 |
| Moorview Windows Limited | Construction | 2003 |
| Morning Rise Care Ltd | Administrative & support | 2026 |
| Most Hated Antisocial Ltd | Professional & scientific | 2025 |
| Motive Ltd | Information & communication | 2022 |
| Mould Eradication Ltd | Construction | 2023 |
| Mount Vale Gardens Management Company Limited | Households | 2020 |
| Mowbray IT Solutions Ltd | Information & communication | 2026 |
| Mpsc Limited | Professional & scientific | 2018 |
| MR Motor 1 Ltd | Wholesale & retail | 2019 |
| MRC Cleaning Ltd | Administrative & support | 2025 |
| MRS Scott's Preserves Limited | Manufacturing | 2019 |
| Ms&F Colwell Holdings Limited | Professional & scientific | 2022 |
| MTL Projects Limited | Professional & scientific | 2019 |
| MTR Solutions Ltd | Administrative & support | 2024 |
| Murtek Business IT Solutions Ltd | Other services | 2007 |
| Murtek Group Limited | Information & communication | 2015 |
| Musgrave Farm LLP | | 2018 |
| MW Business Services Limited | Professional & scientific | 2011 |
| My Carpet Shop Ltd | Extraterritorial | 2020 |
| My Way Logistics Ltd | Transport & logistics | 2025 |
| N & T Armstrong Building Ltd | Construction | 2024 |
| N & T Foundations Ltd | Construction | 2025 |
| N D T Welding Limited | Construction | 1996 |
| N Freight Limited | Transport & logistics | 2011 |
| N Hocking Butchers Limited | Wholesale & retail | 2004 |
| N J Metcalfe Park Services Ltd | Administrative & support | 2022 |
| N R Chef Limited | Hospitality | 2023 |
| N1 Jetting Systems Limited | Administrative & support | 2009 |
| Naillista Ltd | Other services | 2025 |
| National Plasterboard Systems Ltd | Construction | 2018 |
| National Roofing Contractors Limited | Construction | 2025 |
| National Transport Training Solutions Ltd | Professional & scientific | 2026 |
| Natstrzel Ltd | Transport & logistics | 2025 |
| NE Kitchen Installations Ltd | Construction | 2026 |
| NE Refurbz Limited | Construction | 2023 |
| Nedco Contracts (N.E) Limited | Construction | 2010 |
| Neil Gill Associates Painters and Decorators Limited | Construction | 2023 |
| Nela (the Dales) Ltd | Education | 2023 |
| Neue Schule Group Limited | Professional & scientific | 2016 |
| Neue Schule Limited | Manufacturing | 2007 |
| Nevis Resources Limited | Water & waste | 2014 |
| New Albion Ltd | Real estate | 2015 |
| New Auckland Investments Limited | Real estate | 2016 |
| New Beginnings Residential Care Ltd | Health & social care | 2026 |
| New Groundworks Limited | Construction | 2014 |
| Newcastle Technology Solutions Ltd | Information & communication | 2022 |
| Newhall Caravan Park Limited | Hospitality | 2005 |
| Newton Containers Limited | Transport & logistics | 2025 |