| MDS Occupational Therapy Ltd | Other services | 2025 |
| MDT Property Ltd | Real estate | 2019 |
| Mdtransport&Logistics Ltd | Transport & logistics | 2025 |
| MDX Property Ltd | Real estate | 2022 |
| ME & Mine Ltd | Wholesale & retail | 2017 |
| ME & YOU Chippy Limited | Hospitality | 2025 |
| ME 2 U 2 Limited | Health & social care | 2023 |
| ME 2U C.I.C. | Health & social care | 2018 |
| ME 2U Centre Limited | Health & social care | 2017 |
| ME and MA Clinic Community Interest Company | Health & social care | 2025 |
| ME Comms Limited | Professional & scientific | 2023 |
| ME Diddy Homes Limited | Construction | 2022 |
| ME Mackey Buildings Ltd | Real estate | 2025 |
| ME Property Developments Ltd | Real estate | 2025 |
| ME. Logistics Ltd | Transport & logistics | 2025 |
| ME2U Academy CIC | Public administration | 2024 |
| Meade-King,Robinson & Company Limited | Wholesale & retail | 1917 |
| Meadow AP Ltd | Manufacturing | 2024 |
| Meadow Bridge Care Services Limited | Health & social care | 2026 |
| Meadow Forte Ltd | Real estate | 2025 |
| Meadow Hall Construction Ltd | Construction | 2024 |
| Meadow Oak Properties Limited | Real estate | 2021 |
| Meadowbank Holdings Ltd | Financial services | 2020 |
| Meadowcrest Ltd | Wholesale & retail | 2021 |
| Meadowmere Limited | Health & social care | 2026 |
| Meadows Software Solutions Ltd | Information & communication | 2025 |
| Meads Capital Limited | Real estate | 2024 |
| Meadstone Developments Limited | Real estate | 2001 |
| Meadstone Limited | Real estate | 1982 |
| Meadway Support Ltd | Education | 2023 |
| Meandre Ltd | Information & communication | 2024 |
| Meat & 2 VEG Ltd | Wholesale & retail | 2023 |
| Meat & Eats Liverpool Limited | Hospitality | 2019 |
| Meat & Flame Ltd | Hospitality | 2025 |
| Meat Leisure Limited | Hospitality | 2022 |
| Meatball Bros Ltd | Hospitality | 2026 |
| Meatballs 17 Ltd | Hospitality | 2024 |
| Meate Consultancy Ltd | Real estate | 2023 |
| Meatless Limited | Hospitality | 2019 |
| Meatless Meal Prep Co. Ltd | Manufacturing | 2022 |
| Mebius Entertainment Limited | Arts & recreation | 2024 |
| MEC Merseyside Ltd | Construction | 2021 |
| Mech Contracts Ltd | Manufacturing | 2025 |
| Mech Installation Ltd | Wholesale & retail | 2026 |
| Mech-Air Building Services Limited | Construction | 1984 |
| Mech-Tech Limited | Professional & scientific | 2025 |
| Mech.Maintenance & Services Ltd | Professional & scientific | 2026 |
| Mechabit Ltd | Information & communication | 2013 |
| Mechanical Automation Design Engineering Ltd | Professional & scientific | 2025 |
| Mechanical Handling Consultants (Aviation) Limited | Manufacturing | 1977 |
| Mechanicsbay Limited | Information & communication | 2026 |
| Mecherre Limited | Real estate | 2019 |
| Mechfab Ltd | Professional & scientific | 2025 |
| Mechforce Global Ltd | Manufacturing | 2025 |
| Meck Homes Limited | Real estate | 2023 |
| Mecrocorp Technology Ltd | Information & communication | 2026 |
| Mecx Group Limited | Administrative & support | 2008 |
| Mecx Holdings Limited | Financial services | 2014 |
| MED Media Group Limited | Professional & scientific | 2020 |
| Medano Labs Ltd | Information & communication | 2024 |
| Medaxxess Limited | Wholesale & retail | 2021 |
| Medcalf Properties Limited | Administrative & support | 2008 |
| Mede-Care Healthcare Solutions Ltd | Information & communication | 2012 |
| Medex Reports and Rehab Ltd | Other services | 2012 |
| Medfs Limited | Financial services | 2014 |
| Media 111 Ltd | Professional & scientific | 2025 |
| Media 786 Productions Ltd | Information & communication | 2024 |
| Media Arts North Initiative | Other services | 2005 |
| Media Box Nationwide Limited | Information & communication | 2011 |
| Media Europe Limited | Information & communication | 2017 |
| Media Link Global Ltd | Wholesale & retail | 2024 |
| Media Make-Up Management Ltd | Other services | 2014 |
| Media Share Group Ltd | Professional & scientific | 2015 |
| Media Walls Liverpool Ltd | Construction | 2026 |
| Mediasat TV Ltd | Information & communication | 2021 |
| Mediation Management Consutling Limited | Health & social care | 2017 |
| Mediation Solutions UK Ltd | Administrative & support | 2020 |
| Medical AI Research Limited | Health & social care | 2026 |
| Medical Care Services Ltd | Health & social care | 2022 |
| Medical Education and Development Ltd | Real estate | 2015 |
| Medical Haven Ltd | Health & social care | 2023 |
| Medical Justice Ltd | Extraterritorial | 2012 |
| Medical Thermography UK Ltd | Administrative & support | 2023 |
| Medical Wealth Management Limited | Financial services | 2025 |
| Medical Weight Loss Global Limited | Health & social care | 2023 |
| Medical Weightloss 4 U Ltd | Health & social care | 2021 |
| Medicalia Ltd | Professional & scientific | 2017 |
| Medically Minded Ltd | Health & social care | 2021 |
| Medicash Health Benefits (Services) Limited | Administrative & support | 2002 |
| Medicash Health Benefits Limited | Financial services | 1931 |
| Medicines in Mental Health Limited | Health & social care | 1988 |
| Mediconsent Limited | Information & communication | 2018 |
| Mediconsult Ltd | Professional & scientific | 2023 |
| Medicus Plus Limited | Administrative & support | 2017 |
| Medida Consultants Limited | Professional & scientific | 2021 |
| Mediflow Limited | Information & communication | 2015 |
| Mediform Limited | Manufacturing | 2018 |
| Mediform London Limited | Manufacturing | 2021 |
| Mediklinic Ltd | Education | 2023 |
| Medilase Aesthetics Ltd | Other services | 2023 |