| M.S.S. Susch Limited | Hospitality | 2009 |
| M2 Solutions Ltd | Information & communication | 2016 |
| M2S Consultancy Private Limited | Information & communication | 2016 |
| MA (Law & Governance) Limited | Professional & scientific | 2011 |
| MA Arbitrage Ltd | Wholesale & retail | 2024 |
| MA17 OB Ltd | Real estate | 2026 |
| MA34 Catering Ltd | Hospitality | 2024 |
| Maahi Mittal Limited | Health & social care | 2015 |
| MAC & Apol Ltd | Health & social care | 2024 |
| MAC Consultancy (Midlands) Ltd | Information & communication | 2018 |
| MAC GAS / Plumbing / Heating Limited | Construction | 2021 |
| MAC GAS Installations Limited | Construction | 2023 |
| MAC Properties and Investments Limited | Real estate | 2024 |
| Macc (Midlands) Ltd | Administrative & support | 2013 |
| Mackadown Day Care Services Ltd | Health & social care | 2022 |
| Macniven and Cameron Limited | Manufacturing | 2014 |
| Macott Investment Holdings Limited | Real estate | 1991 |
| MAD Heaters Ltd | Wholesale & retail | 2020 |
| Madden Recruitment Solutions Limited | Administrative & support | 2018 |
| Made Consult Limited | Professional & scientific | 2021 |
| Made for Shade Ltd | Construction | 2024 |
| Made in Rwanda Ltd | Wholesale & retail | 2019 |
| Made Vinci Limited | Wholesale & retail | 2024 |
| Madmud Ltd | Wholesale & retail | 2022 |
| Madrid Cutz ( Birmingham) Limited | Other services | 2022 |
| Madwood Contracts Ltd | Construction | 2020 |
| Magaqua Limited | Wholesale & retail | 2022 |
| Magdalena ROG Ltd | Transport & logistics | 2022 |
| Magenta Inventory and Property Services Limited | Real estate | 2021 |
| Maggiemax Ltd | Real estate | 2019 |
| Magical Home Care Limited | Wholesale & retail | 2012 |
| Magical Moments Hire Limited | Hospitality | 2018 |
| Magnificent Obsessions Limited | Transport & logistics | 1987 |
| Maharajah Takeaway Limited | Hospitality | 2026 |
| Mahony & Ward Limited | Extraterritorial | 1953 |
| MAI Making Animals Important Ltd | Wholesale & retail | 2020 |
| Main Road Films Ltd | Information & communication | 2018 |
| Mainland Haulage Limited | Transport & logistics | 2014 |
| Mainstream Print Limited | Manufacturing | 2012 |
| Mairnh Ltd | Real estate | 2023 |
| MAJ Property Investment Limited | Real estate | 2022 |
| Majestic Social Housing Ltd | Real estate | 2025 |
| Majid and Co Ltd | Health & social care | 2013 |
| Majornurrsing Ltd | Public administration | 2025 |
| MAK Property Holdings Ltd | Real estate | 2025 |
| Make ME a Comic Ltd | Arts & recreation | 2016 |
| Makeney Investment Company Limited | Financial services | 2021 |
| Makers Circle CIC | Education | 2023 |
| Makin Garden Designs Limited | Administrative & support | 1999 |
| Mako Consulting Ltd | Information & communication | 2017 |
| Maks Chemist Limited | Wholesale & retail | 2017 |
| Malani Ltd | Health & social care | 2022 |
| Malard Ltd | Hospitality | 2019 |
| Malcolm Barker Recruitment Ltd | Administrative & support | 2015 |
| Malcolm Gray & Associates (Sutton) Limited | Wholesale & retail | 2011 |
| Malcolm J Presland Limited | Extraterritorial | 1987 |
| Malhi Capital Investments Ltd. | Real estate | 2017 |
| Malvern Estates (New Homes) Limited | Real estate | 2007 |
| Malvern Estates Public Limited Company | Construction | 1988 |
| Malvern Homes (Bluebird) Limited | Construction | 2022 |
| Malwa Capitals Ltd | Financial services | 2024 |
| Malwa Properties Limited | Real estate | 2024 |
| Mama Afric Limited | Wholesale & retail | 2020 |
| MAN and a Van Sutton Coldfield and Birmingham Ltd | Transport & logistics | 2023 |
| MAN Co Oakthorpe Limited | Real estate | 2021 |
| Management Assets Capital Limited | Financial services | 2020 |
| Management Logistics Limited | Professional & scientific | 2015 |
| Manak Commercial Limited | Real estate | 2023 |
| Manak Investments Limited | Real estate | 2021 |
| Maney Hill Limited | Construction | 2021 |
| Maney Houses Limited | Real estate | 2022 |
| Mangosteen Designs Limited | Professional & scientific | 2023 |
| Manhattans Travel Management Ltd | Administrative & support | 2018 |
| Manifesto Football UK Ltd | Professional & scientific | 2025 |
| Manila Enterprises Limited | Professional & scientific | 2018 |
| Mannerings Limited | Extraterritorial | 1983 |
| Manning Estates Limited | Real estate | 2025 |
| Manor Freight Services Limited | Transport & logistics | 2008 |
| Manort Construction Limited | Construction | 2009 |
| Manpower Resources Limited | Administrative & support | 2006 |
| Manpreet Singh Photography Ltd | Professional & scientific | 2015 |
| Manproj Ltd | Information & communication | 2009 |
| Mansfield & Ashfield Broadcasting Company Limited | Information & communication | 1997 |
| Mansformation Ltd | Administrative & support | 2017 |
| Mansoor Medicare Ltd | Health & social care | 2018 |
| Mantra Projects Limited | Construction | 2026 |
| Maocai International Ltd | Hospitality | 2024 |
| Maori Holdings Limited | Professional & scientific | 2017 |
| MAP Talent Group Limited | Administrative & support | 2018 |
| MAP Talent Limited | Administrative & support | 2018 |
| Mapd Holdings Ltd | Financial services | 2026 |
| Mapelton Ltd | Real estate | 2021 |
| Maple Court (Sutton Coldfield) Management Company Limited | Households | 2013 |
| Mapsf Business Support Ltd | Professional & scientific | 2023 |
| MAR Pipework Limited | Construction | 2024 |
| Marbail Gardens and Landscape Design Limited | Other services | 2016 |
| Marble & Granite Tooling Supplies UK Ltd | Wholesale & retail | 2012 |
| Marblewood Homes Limited | Real estate | 2025 |
| Marcelgate Limited | Real estate | 2017 |
| March Building Services Limited | Construction | 1993 |