| MCR Fashion Ltd | Wholesale & retail | 2025 |
| MCR Logistics CC Ltd | Transport & logistics | 2024 |
| MCR UK Enterprise Ltd | Administrative & support | 2025 |
| Mcrb Consulting Ltd | Professional & scientific | 2018 |
| MCS Car Sales Ltd | Wholesale & retail | 2026 |
| MCS Consultancy Services Ltd | Information & communication | 2024 |
| MDB Strategic Developments Limited | Professional & scientific | 2017 |
| MDS Roofing Building and Plumbing Ltd | Construction | 2024 |
| Meadow Wood Ltd | Wholesale & retail | 2016 |
| Meadows Care Holdco Limited | Health & social care | 2020 |
| Meadows Care Limited | Health & social care | 2004 |
| Meadows Psychology Services Limited | Health & social care | 2023 |
| Meadowsmist Cleaning Services Ltd | Administrative & support | 2025 |
| MEC Fitters Ltd | Professional & scientific | 2019 |
| Medallion Property Ltd | Real estate | 2020 |
| Medi Growth Limited | Financial services | 2022 |
| Medical Scans Ltd | Health & social care | 2012 |
| Medical Services Agency Limited | Administrative & support | 2011 |
| Medium Data Ltd | Extraterritorial | 2025 |
| Medmeat Ltd | Health & social care | 2022 |
| Medvance Ltd | Health & social care | 2019 |
| Meeral Services Limited | Health & social care | 2024 |
| MEG - Social Care Ltd | Health & social care | 2017 |
| Megamij Ltd | Hospitality | 2024 |
| Megaretailer Limited | Wholesale & retail | 2024 |
| Megatrack Ltd | Construction | 2006 |
| Melia International Ltd | Wholesale & retail | 2024 |
| Melissa Claire Limited | Wholesale & retail | 2025 |
| Melky Limited | Transport & logistics | 2025 |
| Mellor Lettings Limited | Real estate | 2021 |
| Mellor Street Garage Ltd | Wholesale & retail | 2025 |
| Mellowhide Products Limited | Extraterritorial | 1980 |
| MEM Spec Ltd | Construction | 2022 |
| Mensroom Ltd | Other services | 2025 |
| Mentoria Digitals. Ltd | Other services | 2023 |
| MEO Private Limited | Wholesale & retail | 2026 |
| MER Shop Ltd | Wholesale & retail | 2024 |
| Mercer Visual Productions Limited | Information & communication | 2021 |
| Merchant DE Ville Limited | Information & communication | 2021 |
| Mercury Technology Limited | Extraterritorial | 2020 |
| Merefield Motors Ltd | Wholesale & retail | 2022 |
| Meridian Fire and Security Ltd | Construction | 2017 |
| Merlin Park Management Limited | Real estate | 2006 |
| Merlin Trafford Park (2005) Limited | Real estate | 2005 |
| Merlin Trafford Park Ltd | Real estate | 2004 |
| Meta Consulting Group Ltd | Administrative & support | 2018 |
| Metacol Ltd | Manufacturing | 2015 |
| Metrohive Limited | Wholesale & retail | 2025 |
| Metus Ltd | Professional & scientific | 2007 |
| Mexican Chilli Ltd | Hospitality | 2020 |
| MF Direct Limited | Wholesale & retail | 2018 |
| MFH Consultants Ltd | Administrative & support | 2026 |
| MFL (BL1) Ltd | Financial services | 2023 |
| MFM Cafe Limited | Hospitality | 2024 |
| MG Builders PVT Ltd | Construction | 2023 |
| MG Carpets & Vinyls Ltd | Wholesale & retail | 2024 |
| Mgbms Limited | Professional & scientific | 2015 |
| MGH Waste Ltd | Water & waste | 2025 |
| MGK Property Development Ltd | Real estate | 2024 |
| MGM Healthcare Ltd | Health & social care | 2021 |
| MGR Deliveries Ltd | Transport & logistics | 2025 |
| MH Appliances Ltd | Wholesale & retail | 2024 |
| MH Enterprises Nationwide Ltd | Wholesale & retail | 2016 |
| MH Law Limited | Other services | 2015 |
| MHA Medical Ltd | Health & social care | 2024 |
| Mhaab Ltd | Professional & scientific | 2024 |
| MHG Textiles Limited | Wholesale & retail | 2018 |
| MHH NW Ltd | Wholesale & retail | 2024 |
| MHT Group Ltd | Wholesale & retail | 2020 |
| Mhzr Ltd | Wholesale & retail | 2026 |
| MIB Transport Ltd | Transport & logistics | 2025 |
| MICARE9 Ltd | Health & social care | 2024 |
| Micawber Limited | Administrative & support | 2007 |
| Michael Byrne Building Services Limited | Construction | 2026 |
| Michael Chapman Accounting Ltd | Professional & scientific | 2025 |
| Michael Welsh Limited | Administrative & support | 2002 |
| Michaela Corder Education Ltd | Education | 2026 |
| Mick Bennett Ltd | Professional & scientific | 2010 |
| Mick George Homes (O/M) Ltd | Construction | 2021 |
| Midas Facilities Management Limited | Administrative & support | 2020 |
| Midaz Page | Professional & scientific | 2024 |
| Middleton Blinds & Shutters Ltd | Manufacturing | 2025 |
| Middleton Football Club Ltd | Arts & recreation | 2026 |
| Midgies ' Childcare Limited | Health & social care | 2014 |
| Midwater Limited | Professional & scientific | 2024 |
| MIJ Trading Ltd | Wholesale & retail | 2025 |
| Mikacom IT Solutions Limited | Information & communication | 2003 |
| Mikhail Corp Ltd | Professional & scientific | 2022 |
| Milam Limited | Information & communication | 2018 |
| Milay’S Kitchen Limited | Wholesale & retail | 2025 |
| Mildskystech Consultants Limited | Information & communication | 2024 |
| Mile House Consulting Limited | Professional & scientific | 2015 |
| Milieu Associates Limited | Professional & scientific | 2025 |
| Milk to Mash Ltd | Hospitality | 2023 |
| Milky Way (UK) Ltd | Hospitality | 2013 |
| Millabout Ltd | Hospitality | 2020 |
| Millcare Limited | Administrative & support | 2023 |
| Millennium Security & Electrics Holding Ltd | Financial services | 2025 |
| Millennium Security & Electrics Ltd | Construction | 2025 |
| Millfold Electrical Limited | Construction | 2024 |