| Mainline Products (UK) Limited | Construction | 2009 |
| Major Motors Holdings Ltd | Financial services | 2024 |
| Mango 2 Collective Ltd | Health & social care | 2025 |
| Mango Top Collective Ltd | Financial services | 2025 |
| Mardle Way Ltd | Real estate | 2021 |
| Mariam International Media Ltd | Arts & recreation | 2023 |
| Marley Creative Ltd | Professional & scientific | 2014 |
| Marshlal Automotives Limited | Wholesale & retail | 2024 |
| Marson Garages (Wolstanton) Limited | Wholesale & retail | 1960 |
| Matrix Physio Holdings Limited | Financial services | 2021 |
| Mazards Ltd | Administrative & support | 2020 |
| MCD Electrical Contractors Limited | Construction | 2022 |
| Mcguinness Bros Skip Hire Ltd | Water & waste | 2020 |
| Mcguinness Metals Ltd | Wholesale & retail | 2020 |
| Meadow Building Services Ltd | Construction | 2017 |
| Meadow Properties (Staffs) Limited | Real estate | 2026 |
| Mechanical Integrity Solutions Limited | Administrative & support | 2005 |
| Mectec Engineering (NW) Ltd | Manufacturing | 2022 |
| Medchemica Holdings Limited | Financial services | 2020 |
| MEDI8 Limited | Administrative & support | 2007 |
| Medicalcrib Ltd | Transport & logistics | 2017 |
| Medicare for YOU Limited | Health & social care | 2018 |
| Meel Group (Sustainability Solutions) Limited | Construction | 2021 |
| Meel Group Limited | Financial services | 2017 |
| Mega Brands Limited | Wholesale & retail | 2019 |
| Mejj Ltd | Extraterritorial | 2013 |
| Mejoolies Ltd | Wholesale & retail | 2017 |
| Meljo Mathew Ltd | Health & social care | 2016 |
| Melltray Ltd | Hospitality | 2022 |
| Mereview Consultants Limited | Professional & scientific | 2019 |
| MF Plumbing and GAS Limited | Construction | 2015 |
| MGM Clinical Consultancy Ltd | Professional & scientific | 2020 |
| MH Distribution Solutions Limited | Transport & logistics | 2020 |
| MHW Technical Services Ltd | Professional & scientific | 2014 |
| Microstone Ltd | Wholesale & retail | 2025 |
| Middle Access Solutions Limited | Manufacturing | 2019 |
| Midi VAC Tankers Limited | Wholesale & retail | 2025 |
| Midpeak Property Developments Ltd | Real estate | 2024 |
| Mike Smith Motorsport Limited | Arts & recreation | 2015 |
| Mill Court Management Company (Trentham) Limited | Households | 2001 |
| Milliemae Limited | Wholesale & retail | 2022 |
| Minton Financial Services Limited | Administrative & support | 2010 |
| Miss Moneypennys Brand Limited | Professional & scientific | 2005 |
| Missing Peace Limited | Real estate | 2021 |
| Mister Shifter Services Ltd | Water & waste | 2025 |
| Mizzz P Homes Limited | Real estate | 2025 |
| MJB Lettings Limited | Real estate | 2003 |
| MJW Additive Manufacturing Ltd | Professional & scientific | 2025 |
| MLH Products Limited | Wholesale & retail | 2014 |
| Moderni Capital Limited | Professional & scientific | 2023 |
| Moores Hvac Ltd | Professional & scientific | 2018 |
| Moorview Group Ltd | Financial services | 2020 |
| More Telemarketing Limited | Information & communication | 2019 |
| Mosschem Limited | Wholesale & retail | 2025 |
| Motor Finders Ltd | Professional & scientific | 2021 |
| Motor Sports Timing UK Limited | Administrative & support | 2008 |
| Motorchoiceuk Limited | Wholesale & retail | 2020 |
| MR Mosaics Ltd | Wholesale & retail | 2012 |
| MRW Commercial Trading Limited | Administrative & support | 2021 |
| MS Quantum Holdings Ltd | Financial services | 2025 |
| MS Trading Companies Ltd | Administrative & support | 2017 |
| MTP Dental Ltd | Health & social care | 2015 |
| Mucklestone Limited | Wholesale & retail | 2018 |
| Murshad Studio Ltd | Information & communication | 2024 |
| MWB Rentals Limited | Real estate | 2024 |
| My Cucina Limited | Hospitality | 2014 |
| My Desi Kitchen Ltd | Hospitality | 2024 |
| Mymentor Ltd | Administrative & support | 2021 |
| Mypremier Security Limited | Wholesale & retail | 2018 |
| N Express Ltd | Hospitality | 2023 |
| N P Property Services Limited | Construction | 2008 |
| N Watson Plumbing Services Ltd | Construction | 2005 |
| N&P Swan Ltd | Wholesale & retail | 2018 |
| Naas Consultancy and Management Limited | Professional & scientific | 2023 |
| Nationcall Limited | Information & communication | 1998 |
| Nationwide Lift Services Ltd | Manufacturing | 2016 |
| Nature Consultancy Limited | Health & social care | 2004 |
| NB Learning Technologies Ltd | Construction | 2018 |
| NBE Brokers Ltd | Financial services | 2022 |
| NC QS Limited | Professional & scientific | 2023 |
| ND360 Education Group Ltd | Education | 2025 |
| Neil Cliffe Vehicle Repairs Limited | Wholesale & retail | 2016 |
| Network Healthcare Solutions Limited | Health & social care | 2005 |
| Networker Global Limited | Information & communication | 2017 |
| New Hope Property Solutions Ltd | Real estate | 2023 |
| Newcastle Mechanical Services Limited | Construction | 2020 |
| Newcastle Retail Management Limited | Information & communication | 2017 |
| Newcastle Town FC Youth (Trading) Limited | Arts & recreation | 2022 |
| Newcastle Town FC Youth Limited | Arts & recreation | 2022 |
| Newcastle Town Football Club Limited | Arts & recreation | 1988 |
| Newcastle UL Valley Heights RTM Company Ltd | Real estate | 2024 |
| Newcastle-Under-Lyme School | Education | 2008 |
| Newera Anaesthetics Ltd | Health & social care | 2005 |
| Nexor Consultancy Limited | Professional & scientific | 2015 |
| Next Step Believe & Achieve Limited | Health & social care | 2019 |
| Nhcc Sports and Social CIC | Arts & recreation | 2016 |
| Nick Edwards Contracts Limited | Agriculture & fishing | 2006 |
| Nina Hair & Beauty Ltd | Other services | 2013 |
| Nish Retail Limited | Wholesale & retail | 2024 |
| Nkolaz PVT Ltd | Administrative & support | 2025 |