| Mcgrath Media Productions Limited | Information & communication | 2004 |
| Mcgurk Build Ltd | Construction | 2025 |
| Mcgurk Building Solutions Ltd | Construction | 2024 |
| Mcgurk Buildmaster Solutions Ltd | Construction | 2025 |
| Mchugh Financial Ltd | Financial services | 2022 |
| Mckelvie Developments Limited | Real estate | 2008 |
| Mckenzie Changes Service Ltd | Education | 2025 |
| Mcleish Property Ltd | Construction | 2026 |
| Mcnaughton Maintenance Ltd | Construction | 2026 |
| MCP Middletons Ltd | Construction | 2018 |
| Mcpheely Homes Limited | Real estate | 2021 |
| Mcpherson Productions Limited | Administrative & support | 2011 |
| MCS Cleaning Limited | Administrative & support | 2017 |
| MCS Housing Management Limited | Hospitality | 2019 |
| MCW Mastery Clarity Wisdom Ltd | Professional & scientific | 2025 |
| Mcwilliam Studio Ltd | Professional & scientific | 2018 |
| MD Riva Recruitment Limited | Administrative & support | 2023 |
| MDA Coaching Services Ltd | Professional & scientific | 2023 |
| MDH Property Management Limited | Real estate | 2024 |
| MDM Advisory Limited | Professional & scientific | 2024 |
| Meadow Pool Limited | Extraterritorial | 1987 |
| Meadowdale Works Ltd | Real estate | 2021 |
| Meadows Financial Solutions Ltd | Financial services | 2010 |
| Mechnotech Ltd | Wholesale & retail | 2023 |
| Medcoversolutions Ltd | Health & social care | 2023 |
| Medecan Ltd | Health & social care | 2016 |
| Medecan Services Limited | Health & social care | 2025 |
| Medi Hands Training and Consultancy Ltd | Professional & scientific | 2023 |
| Media Server Hub Limited | Professional & scientific | 2026 |
| Mediaball Active CIC | Education | 2025 |
| Medialook Limited | Professional & scientific | 1999 |
| Mediashock Ltd | Information & communication | 2003 |
| Medical Answers Limited | Health & social care | 2025 |
| MEDICS4U.COM Ltd | Health & social care | 2019 |
| Medicus Cura Limited | Health & social care | 2013 |
| Medinet Clinical Services Ltd | Health & social care | 2015 |
| Medinet International Holdings Limited | Professional & scientific | 2025 |
| Medinet Modular Services Limited | Health & social care | 2020 |
| Medinet Solutions Limited | Health & social care | 2016 |
| Mediplacers Limited | Professional & scientific | 2025 |
| Medixone Limited | Health & social care | 2025 |
| Medizen Clinics Limited | Health & social care | 2006 |
| Medizen Limited | Health & social care | 2002 |
| Medux Limited | Manufacturing | 2022 |
| Medyx Limited | Information & communication | 2025 |
| MEE CHA Properties Limited | Real estate | 2022 |
| Meehan Investments Ltd | Real estate | 2012 |
| Meers Graphics & Print Limited | Manufacturing | 1999 |
| Mega Selection Limited | Wholesale & retail | 2024 |
| Megabuild Services Ltd | Construction | 2023 |
| Meghamacharla Limited | Professional & scientific | 2025 |
| Meghnetic Ltd | Information & communication | 2022 |
| Mehek Boutique Limited | Wholesale & retail | 2018 |
| MEL Housing Ltd | Hospitality | 2026 |
| MEL Real Estates Ltd | Real estate | 2021 |
| MEL Solutions Ltd | Financial services | 2026 |
| Melgon Fresh Co Ltd | Wholesale & retail | 2025 |
| Melody Developments Limited | Construction | 2014 |
| Melrose Design Studio Ltd | Professional & scientific | 2024 |
| Melrose Housing Ltd | Real estate | 2025 |
| Melw Properties Ltd | Real estate | 2019 |
| Memory Graphics Ltd | Professional & scientific | 2022 |
| Memovo Ltd | Health & social care | 2025 |
| MEN Matter & Co Ltd | Wholesale & retail | 2024 |
| Merchant Funding Advance Ltd | Financial services | 2023 |
| Mercia Financial Services Limited | Financial services | 2015 |
| Mercian Business Services Limited | Information & communication | 2004 |
| Mercian Heating Limited | Construction | 2015 |
| Mere Green Builders Limited | Construction | 1986 |
| Mere Green Holdings Limited | Financial services | 2018 |
| Mere Green Ltd | Professional & scientific | 2024 |
| Merevale Limited | Other services | 2021 |
| Meriden Business Park Management Company Limited | Real estate | 1999 |
| Meridian IT Consulting Ltd | Information & communication | 2018 |
| Merlin Initiatives Limited | Information & communication | 2010 |
| Merlin Trading (West Midlands) Limited | Water & waste | 2016 |
| Merlion Health Limited | Wholesale & retail | 2004 |
| Merlion Holdings Limited | Financial services | 2025 |
| Merritt Brothers Property Services Ltd | Financial services | 2020 |
| Mersey AA Property Ltd | Real estate | 2024 |
| Mersey AA53JUN Ltd | Real estate | 2024 |
| Meta Commerce Ltd | Wholesale & retail | 2026 |
| META4 Business Coaching Limited | Administrative & support | 2010 |
| Metal Adhesives Ltd | Wholesale & retail | 2024 |
| Metal Industries Limited | Professional & scientific | 2013 |
| Metalcraft(Willenhall)Limited | Real estate | 1947 |
| Metals & Alloys Limited | Professional & scientific | 2009 |
| Metropolis 2 Limited | Professional & scientific | 2020 |
| Mews and Yeatmans Limited | Extraterritorial | 1964 |
| Mexum Ltd | Wholesale & retail | 2025 |
| Meynell & South Staffordshire Hunt Limited | Arts & recreation | 2018 |
| MFC Property Limited | Real estate | 2025 |
| Mfmz Enterprise Ltd | Wholesale & retail | 2025 |
| MG 888 Limited | Professional & scientific | 2024 |
| MG Consulting (Birmingham) Limited | Professional & scientific | 2025 |
| MG Nuboutique Ltd | Other services | 2023 |
| Mgap Heating Ltd | Construction | 2026 |
| MGH Consultancy Limited | Construction | 2003 |
| MGM IT Solutions Ltd | Information & communication | 2010 |
| MGM Railway Associates Limited | Professional & scientific | 2014 |