| Mbhpco 1 NE27 0UA Limited | Real estate | 2026 |
| Mbhpco 101 NE63 9JQ Limited | Real estate | 2026 |
| Mbhpco 14 SR7 7JZ Limited | Real estate | 2026 |
| Mbhpco 15 SR7 7JZ Limited | Real estate | 2026 |
| Mbhpco 16 SR7 7JZ Limited | Real estate | 2026 |
| Mbhpco 17 SR7 7JZ Limited | Real estate | 2026 |
| Mbhpco 18 SR7 7LJ Limited | Real estate | 2026 |
| Mbhpco 1A NE27 0UA Limited | Real estate | 2026 |
| Mbhpco 31 NE28 9DQ Limited | Real estate | 2026 |
| Mbhpco 48 NE24 1HP Limited | Real estate | 2026 |
| Mbhpco 5 SR7 7LG Limited | Real estate | 2026 |
| Mbhpco 50 NE24 1HP Limited | Real estate | 2026 |
| Mbhpco 54 GL1 3NZ Limited | Real estate | 2026 |
| Mbhpco 7 NE40 3JS Limited | Real estate | 2026 |
| MBK & SBK Enterprises 786 Ltd | Hospitality | 2015 |
| MBK Property North East Ltd | Real estate | 2024 |
| MBR Cosmetic Surgery Ltd | Health & social care | 2016 |
| MBR Media Ltd | Professional & scientific | 2022 |
| Mbrace Limited | Health & social care | 2016 |
| MBS (Northumberland) Ltd | Professional & scientific | 2017 |
| Mbtw Limited | Health & social care | 2015 |
| MBU Sales Limited | Wholesale & retail | 2024 |
| MC Cars NE Ltd | Wholesale & retail | 2019 |
| MC Marine Solutions Ltd | Professional & scientific | 2019 |
| MC Mechanical Services Ltd | Other services | 2024 |
| MC MEP Consulting Services Ltd | Professional & scientific | 2022 |
| MC Partners (Stokesley) Limited | Real estate | 2011 |
| Mcadam Holdings Limited | Hospitality | 1985 |
| Mcai Ltd | Professional & scientific | 2025 |
| Mcalpine Properties Ltd | Real estate | 2025 |
| Mcandrew Transport Services Limited | Transport & logistics | 2022 |
| Mcardles DMI Ltd | Construction | 2016 |
| MCC Engineering & Technical Services Ltd | Construction | 2024 |
| MCC Lintzford Mill Limited | Real estate | 2011 |
| Mccalden Worrell Industries Limited | Wholesale & retail | 2021 |
| Mccallum Currie Limited | Financial services | 2016 |
| Mccann Property Ltd | Real estate | 2018 |
| Mccarthy Design Solutions Ltd | Professional & scientific | 2023 |
| Mcclannan Ltd | Manufacturing | 2017 |
| Mcclarence Property Ltd | Real estate | 2020 |
| Mccormick Spaces Limited | Real estate | 2025 |
| Mccourt Holdings (UK) Limited | Financial services | 2012 |
| Mccourt Mining (UK) Limited | Mining & quarrying | 2012 |
| Mccrossan Furniture Ltd | Manufacturing | 2013 |
| Mcdon Property Limited | Real estate | 2025 |
| MCG Holdco Limited | Financial services | 2024 |
| Mcgarry DOE Ltd | Real estate | 2019 |
| Mcgillivrays Limited | Real estate | 2013 |
| Mcgovan Engineering Limited | Professional & scientific | 2017 |
| Mcgrady Clarke Group Holdings Ltd | Financial services | 2024 |
| Mcgrady Clarke Group Ltd | Professional & scientific | 2019 |
| Mcguinness Insulation Limited | Manufacturing | 1997 |
| Mcintyre Utilities Limited | Energy | 2022 |
| Mciver Holdings Ltd | Financial services | 2026 |
| MCK Imaging Ltd | Health & social care | 2025 |
| Mckale Property Ltd | Hospitality | 2014 |
| Mckale Property Management Limited | Real estate | 2002 |
| Mckc Property Ltd | Real estate | 2023 |
| Mckeag & Co. Solicitors LLP | | 2015 |
| Mckenna Lettings Ltd | Real estate | 2025 |
| Mckenna Property Holdings Ltd | Financial services | 2025 |
| Mckenzie Real Estates Limited | Real estate | 2002 |
| Mckenzie's Deli Ltd | Hospitality | 2018 |
| Mclaren Homez Ltd | Real estate | 2025 |
| Mcleod Haulage Limited | Transport & logistics | 2016 |
| Mcleod Medical Ltd | Health & social care | 2019 |
| Mclt Limited | Hospitality | 2017 |
| MCN Mechanical and Electrical Limited | Construction | 2025 |
| Mcnair Building Design UK Limited | Professional & scientific | 2018 |
| Mcneil Creative Consultants Ltd | Professional & scientific | 2009 |
| Mcpake Development Solutions Ltd | Professional & scientific | 2018 |
| Mcpherson Heating and Plumbing Ltd | Construction | 2022 |
| MCS Support Services Limited | Administrative & support | 2025 |
| Mcsi Limited | Hospitality | 2026 |
| Mcsykes Property Group Limited | Construction | 2025 |
| Mcugorji Group Limited | Wholesale & retail | 2025 |
| MCV Holdings Ltd | Financial services | 2019 |
| MD ALI Real Estates Ltd | Real estate | 2025 |
| MD Car & Commercial Ltd | Wholesale & retail | 2023 |
| MD Construction and Property Services Limited | Construction | 2026 |
| MDA CAD Ltd | Professional & scientific | 2013 |
| Mdhlt Associate Ltd | Health & social care | 2017 |
| Mdlo Ltd | Real estate | 2025 |
| MDM Agency Ltd | Arts & recreation | 2016 |
| MDM Enterprises Limited | Wholesale & retail | 2009 |
| MDM Stores Limited | Wholesale & retail | 2020 |
| Mdna Life Sciences (UK) Ltd | Professional & scientific | 2005 |
| MDO Care Group Ltd | Administrative & support | 2023 |
| MDS Accountancy Services Ltd | Professional & scientific | 2004 |
| MDS Contracting Limited | Construction | 2018 |
| MDS Plumbing Limited | Construction | 2016 |
| MDV Education Limited | Education | 2012 |
| ME Cronin Ltd | Wholesale & retail | 2007 |
| ME ME ME Recordings Limited | Information & communication | 2018 |
| Meadow Dale Management Company Limited | Real estate | 2006 |
| Meadow Rise (Heighington) Management Company Limited | Households | 2019 |
| Meadowcroft Homes Limited | Construction | 1998 |
| Meadowfield Auto Centre Ponteland Ltd | Wholesale & retail | 2018 |
| Meadownet Limited | Real estate | 2002 |
| Meadowvale (Shiremoor) Management Company Limited | Real estate | 2004 |