| MRS Bubble’S Mobile Tyres Ltd | Wholesale & retail | 2026 |
| MRS Charltons Farm Ltd | Agriculture & fishing | 2023 |
| Mrsr Holdings Ltd | Financial services | 2024 |
| Mrsw Global Ltd | Other services | 2025 |
| MS and GS Medical Limited | Health & social care | 2017 |
| MS Chauffeur Service Ltd | Transport & logistics | 2026 |
| MS Collection Ltd | Wholesale & retail | 2025 |
| MS Commerce Syndicate Ltd | Wholesale & retail | 2024 |
| MS Dream Properties Ltd | Real estate | 2026 |
| MS Energy Limited | Administrative & support | 2018 |
| MS Global Consultancy Limited | Other services | 2025 |
| MS Global Enterprises Ltd | Hospitality | 2026 |
| MS Narang Ltd | Hospitality | 2015 |
| MS Properties (NE) Ltd | Real estate | 2025 |
| MS Properties NCL Ltd | Wholesale & retail | 2024 |
| MS Property (NE) Limited | Real estate | 2013 |
| MS Technologies & Fintech Ltd | Information & communication | 2026 |
| MS Watson Construction Ltd | Construction | 2014 |
| MS Wind Ltd | Construction | 2023 |
| MSA Builders Ltd | Construction | 2025 |
| MSC Computer Training Ltd | Information & communication | 2003 |
| MSC Retail Limited | Wholesale & retail | 2025 |
| MSF Design Ltd | Professional & scientific | 2018 |
| MSG Mechanics Ltd | Wholesale & retail | 2025 |
| MSH Design Ltd | Professional & scientific | 2023 |
| MSI Consulting Limited | Professional & scientific | 2022 |
| MSI Engineering Services Limited | Professional & scientific | 2010 |
| MSI Pharma Ltd | Health & social care | 2015 |
| MSK IT Tech Ltd | Information & communication | 2025 |
| MSK Management Consultancy Ltd | Professional & scientific | 2021 |
| MSK Sports Injury Clinic Limited | Health & social care | 2018 |
| Mslexia Publications Limited | Information & communication | 1997 |
| Msmith Services Ltd | Construction | 2022 |
| MSP Group Ltd | Wholesale & retail | 2025 |
| MSP Plastering Solutions Ltd | Construction | 2025 |
| Msplumbing Services Limited | Construction | 2025 |
| MSQ Catering Limited | Hospitality | 2025 |
| Msrb Properties Ltd | Real estate | 2025 |
| MST Accountants & Business Advisors Limited | Professional & scientific | 2019 |
| Mstaxi NCL Limited | Transport & logistics | 2022 |
| Mstream Community UK Ltd | Administrative & support | 2024 |
| MT Investment NE Ltd | Real estate | 2022 |
| MT Property (Newcastle) Ltd | Real estate | 2020 |
| Mt-Itsolutions Ltd | Wholesale & retail | 2025 |
| MTD Medical Services Ltd | Professional & scientific | 2025 |
| Mtfc Sports Camps Limited | Arts & recreation | 2019 |
| MTH Consulting Limited | Professional & scientific | 2024 |
| MTH Newcastle Ltd | Wholesale & retail | 2017 |
| Mticollections Ltd | Wholesale & retail | 2021 |
| MTL Hire Ltd | Administrative & support | 2020 |
| MTL Scaffolding Limited | Construction | 2002 |
| MTM Spices Ltd | Hospitality | 2024 |
| Mtmvibe Ltd | Information & communication | 2025 |
| MTN Care Ltd | Health & social care | 2022 |
| MTR Enterprises Limited | Professional & scientific | 1999 |
| MTR Technology Limited | Information & communication | 2022 |
| Mtrec Limited | Administrative & support | 2006 |
| MTS Holdings(Northeast) Ltd | Professional & scientific | 2025 |
| MTW County Limited | Financial services | 2008 |
| MTW Electrical Contractors Limited | Construction | 2012 |
| Muckle Director Limited | Professional & scientific | 2004 |
| Muckle LLP | | 2005 |
| Muckle Secretary Limited | Professional & scientific | 2004 |
| Muckle Services Limited | Professional & scientific | 2010 |
| Muckle Trustee Limited | Financial services | 2021 |
| MUD Brand Limited | Households | 2023 |
| Mufaro Private Limited Limited | Public administration | 2022 |
| Mugg'D Ltd | Other services | 2025 |
| Mughal Enterprises Limited | Wholesale & retail | 2025 |
| Muhammad Basit Logistics Limited | Transport & logistics | 2025 |
| Mukaj Property Ltd | Real estate | 2026 |
| MUL Studio Ltd | Arts & recreation | 2026 |
| Mul-V Property Ltd | Real estate | 2017 |
| Mulberry Holiday LET Ltd | Hospitality | 2025 |
| Mulberry Homes NE (Site 1) Limited | Real estate | 2025 |
| Mulberry Homes NE (Site 2) Limited | Real estate | 2025 |
| Mulberry Homes NE Ltd | Real estate | 2015 |
| Mulberry Investments (North East) Limited | Real estate | 2022 |
| Mulberry Trading (North East) Limited | Construction | 2022 |
| Mulfont Limited | Extraterritorial | 2012 |
| Mulholland Energy Services Ltd | Construction | 2014 |
| Mulkh RAJ Properties Ltd | Real estate | 2026 |
| Mull Media Ltd | Professional & scientific | 2024 |
| Mulligans Cafe Limited | Hospitality | 2024 |
| Mullin Properties Ltd | Real estate | 2026 |
| Multi-Ceramic Technology LLP | | 2009 |
| Multi-Lab Limited | Manufacturing | 1988 |
| Multi-Service-Burea Ltd | Administrative & support | 2025 |
| Multichoice UK Ltd. | Wholesale & retail | 2011 |
| Multiconnect Communication Services Ltd | Construction | 2015 |
| Multiminded Limited | Professional & scientific | 2010 |
| Multiphase Ltd | Construction | 2012 |
| Multiply Capital Management Limited | Real estate | 2023 |
| Multistance Ltd | Wholesale & retail | 2024 |
| Mumbai Cafe Limited | Wholesale & retail | 2023 |
| Mums Food Newcastle Ltd | Hospitality | 2025 |
| Mumtaz Fast Food Ltd | Hospitality | 2017 |
| Munromedicine Limited | Education | 2022 |
| Munsif Ltd | Hospitality | 2024 |
| MUO Limited | Information & communication | 2006 |