| Membership Management Systems Ltd | Administrative & support | 2017 |
| Memmott Enterprises Limited | Hospitality | 2024 |
| Mentor Build Projects Ltd | Other services | 2025 |
| Menu World Limited | Information & communication | 2018 |
| Menzie Enterprise Ltd | Transport & logistics | 2019 |
| Meon Vale Management Company Limited | Households | 2013 |
| Meow Hotel & Small Paws Ltd | Hospitality | 2025 |
| Meraki Design Studio Ltd | Construction | 2023 |
| Mercaston Tree Company Limited | Administrative & support | 2004 |
| Mercaston Willow Limited | Agriculture & fishing | 2020 |
| Merchant Property Development Limited | Construction | 2017 |
| Merchants Corner (Derby) Management Company Limited | Real estate | 2003 |
| Mercia Court Management Repton Limited | Households | 2005 |
| Mercia Developments Limited | Construction | 2009 |
| Mercia Drilling Ltd | Construction | 2025 |
| Mercia Electrical Ltd | Construction | 2020 |
| Mercia Promenade Management Limited | Households | 2024 |
| Mercia Property Services Limited | Construction | 2025 |
| Mercia Services Group Ltd. | Transport & logistics | 2020 |
| Mercia Solar & EV Ltd | Construction | 2021 |
| Mercian Contracting Services Ltd | Professional & scientific | 2018 |
| Mercian Cycles Derby Limited | Manufacturing | 2024 |
| Mercian Fabrication and Welding Limited | Manufacturing | 2018 |
| Mercian Utilities Limited | Energy | 2018 |
| Mercian Ventures Ltd | Professional & scientific | 2024 |
| Mercury Plumbing & Heating Limited | Construction | 2008 |
| Mercutio Entertainment Limited | Information & communication | 2021 |
| Meridian (Leicester) Limited | Financial services | 2014 |
| Meridian Care Academy Limited | Education | 2026 |
| Meridian Holdings Group Ltd | Financial services | 2019 |
| Meridian Mortgages Limited | Financial services | 2006 |
| Merino Health Limited | Health & social care | 2019 |
| Merivida Limited | Information & communication | 2025 |
| Merlin 997 Limited | Professional & scientific | 2009 |
| Merlin Aerotech Limited | Professional & scientific | 2011 |
| Merlin Consultants Ltd | Administrative & support | 2022 |
| Merlin Derby Limited | Financial services | 2023 |
| Merlin Park Management (Derby) Limited | Real estate | 2023 |
| Merlin Wealth Management Limited | Financial services | 2009 |
| Mermec UK Limited | Transport & logistics | 2005 |
| Merrifield Comms Ltd | Arts & recreation | 2013 |
| Merrifields Holdings Limited | Financial services | 2025 |
| Merrifields Limited | Financial services | 2005 |
| Merrion Limited | Professional & scientific | 2017 |
| Merrybower Arts & Craft's Studio Limited | Education | 2020 |
| Merton House Flats Management Company Limited | Households | 1980 |
| Meska Fire & Security Ltd | Administrative & support | 2025 |
| Messrs Greenhalgh & Mcmanus Ltd | Real estate | 2021 |
| Mester Optics Ltd | Professional & scientific | 2026 |
| Metal Fabrication Supplies Limited | Wholesale & retail | 2005 |
| Metal Finishers Ltd | Manufacturing | 2011 |
| Metal Work Midland Ltd | Manufacturing | 2020 |
| Metalcore Construction Ltd | Construction | 2025 |
| Metallon (Derby) Holdings Limited | Professional & scientific | 2009 |
| Metallon (Derby) Limited | Wholesale & retail | 1997 |
| Metapro-Tex Ltd | Manufacturing | 2010 |
| Metasafe Limited | Administrative & support | 2022 |
| Metatongue Ltd | Professional & scientific | 2022 |
| Methodist Homes | Health & social care | 2000 |
| Methoxy Limited | Wholesale & retail | 2025 |
| Metkey 1 Ltd | Real estate | 2017 |
| Metkey Developments Limited | Real estate | 2016 |
| Metrix Nutrition Ltd | Health & social care | 2018 |
| Metrixconection Ltd | Administrative & support | 2019 |
| Metro Bar Ltd | Hospitality | 2021 |
| Metro Finance Brokers Limited | Financial services | 2003 |
| Metrology Collective Ltd | Information & communication | 2025 |
| Metrotech Systems Limited | Information & communication | 2020 |
| MEX Worldwide Logistic Limited | Transport & logistics | 2025 |
| Mexiv Mart Ltd | Wholesale & retail | 2026 |
| Meyers Electrical Solutions Ltd | Construction | 2023 |
| MF Construction (Midlands) Limited | Construction | 2006 |
| MF Dance (South) LLP | | 2016 |
| MF Development Company UK Limited | Construction | 1999 |
| MF Development Funding Company UK Limited | Construction | 2001 |
| MF Education Ltd | Education | 2025 |
| MF Fit Pots Ltd | Manufacturing | 2026 |
| MF Martial Arts (South) LLP | | 2016 |
| MF Opulence Limited | Real estate | 2025 |
| MF POD Bath & Wilts Ltd | Education | 2025 |
| MF POD Berkshire and Oxfordshire Ltd | Education | 2025 |
| MF POD Buckinghamshire Ltd | Education | 2025 |
| MF POD Consultancy Ltd | Education | 2025 |
| MF POD Dance Berkshire Ltd | Education | 2025 |
| MF POD Dance Newbury Ltd | Education | 2025 |
| MF POD Dance Nottinghamshire Ltd | Education | 2025 |
| MF POD Dance Oxfordshire Ltd | Education | 2025 |
| MF POD Dance Swindon Ltd | Education | 2025 |
| MF POD Dance West Oxfordshire Ltd | Education | 2025 |
| MF POD Dance Wiltshire and Bristol Ltd | Education | 2025 |
| MF POD East Berkshire Ltd | Education | 2025 |
| MF POD Gloucestershire Ltd | Education | 2025 |
| MF POD Gradings Ltd | Education | 2025 |
| MF POD Hampshire and North Surrey Ltd | Education | 2025 |
| MF POD Marketing Ltd | Administrative & support | 2018 |
| MF POD Merch Ltd | Arts & recreation | 2016 |
| MF POD MID Ulster Ltd | Education | 2025 |
| MF POD Midlands Ltd | Education | 2025 |
| MF POD Monmouthshire Ltd | Education | 2025 |
| MF POD North , South and West Swindon Ltd | Education | 2025 |