| MAK Distribution (Birmingham) Ltd | Transport & logistics | 2018 |
| Maks Insulation & Construction Ltd | Construction | 2024 |
| Malhotra Construction Limited | Construction | 2017 |
| Maliks Estates Limited | Real estate | 2019 |
| Malren Global Trade Ltd | Wholesale & retail | 2024 |
| Malvern Gardens Limited | Households | 2026 |
| Mamina Support & Care Ltd | Administrative & support | 2022 |
| Management Soul Limited | Professional & scientific | 2009 |
| Manraj Logistics Limited | Transport & logistics | 2026 |
| Manroop Sahota Transport Ltd | Transport & logistics | 2025 |
| Manuel Trans Ltd | Transport & logistics | 2025 |
| Maran Trans Ltd | Transport & logistics | 2014 |
| Marina Bracelets Ltd | Manufacturing | 2024 |
| Mark Harrison Services Limited | Transport & logistics | 2026 |
| Marketer and ME Ltd | Information & communication | 2025 |
| Marshall Electrical Solutions Ltd | Construction | 2021 |
| Martin Novak Limited | Transport & logistics | 2024 |
| Marvelush Finish Ltd | Administrative & support | 2021 |
| Mashmelo Limited | Health & social care | 2022 |
| Masiuk Properties Ltd | Real estate | 2019 |
| Master Mechanic U.K. Limited | Wholesale & retail | 2026 |
| Mastermix Ltd | Wholesale & retail | 2014 |
| Mastery Homes Ltd | Construction | 2026 |
| Matcom NET Limited | Other services | 2019 |
| Matko a Kubko Logistics Limited | Transport & logistics | 2013 |
| Maurchi Care Limited | Health & social care | 2024 |
| Maven Pharmacy Limited | Wholesale & retail | 2020 |
| Mayibongwe Ltd | Health & social care | 2013 |
| Maynard Catering Ltd | Hospitality | 2018 |
| Mazgal Haulage Ltd | Administrative & support | 2023 |
| MAZI80 Ltd | Transport & logistics | 2017 |
| Mazinyani Ltd | Transport & logistics | 2025 |
| MB Solution Team Ltd | Construction | 2023 |
| MC Beck Properties Limited | Real estate | 2016 |
| MC Building Services Midlands Ltd | Construction | 2023 |
| MC Curie Associates Limited | Administrative & support | 2002 |
| MC Curie Tax Accountants Ltd | Professional & scientific | 2013 |
| MC Transport Tipton Ltd | Transport & logistics | 2008 |
| MDA Luxury Hire Ltd | Transport & logistics | 2021 |
| Medical and Electrical Services Limited | Construction | 2017 |
| Medical Device Springs Limited | Manufacturing | 2018 |
| Medical Systems International Limited | Professional & scientific | 1996 |
| Mediceyes Consulting Limited | Health & social care | 2020 |
| Medicure Medical Medical Services Ltd | Health & social care | 2024 |
| Mela Services Limited | Construction | 2016 |
| Mellyz Ltd | Wholesale & retail | 2020 |
| Melvynjones Ltd | Extraterritorial | 2025 |
| Memado Medics Limited | Health & social care | 2015 |
| Membri Healthcare Limited | Health & social care | 2022 |
| Memorable Living Ltd | Real estate | 2024 |
| Mens Logistics and Estates Ltd. | Transport & logistics | 2014 |
| Mercia Rolling Bearings Limited | Professional & scientific | 1995 |
| Metalsy Limited | Manufacturing | 2025 |
| Metrocart UK Ltd | Wholesale & retail | 2022 |
| Mezzstore Limited | Extraterritorial | 2004 |
| Mgaa Online Ltd | Wholesale & retail | 2021 |
| Mgaa Transport Ltd | Transport & logistics | 2021 |
| MGG70 Ltd | Transport & logistics | 2018 |
| Mgkr Limited | Transport & logistics | 2021 |
| Mgmaryo Ltd | Transport & logistics | 2025 |
| MI Mortgages Limited | Financial services | 2019 |
| Miah's Accountancy Services Ltd | Professional & scientific | 2015 |
| Miapi Real-Estate Ltd | Real estate | 2025 |
| Michael Anastassiades Limited | Wholesale & retail | 2012 |
| Michael Brett Construction Services Ltd | Construction | 2018 |
| Midfleet Logistics Solutions Ltd | Transport & logistics | 2025 |
| Midland BMS Ltd | Extraterritorial | 2024 |
| Midland Lamps and Panels Limited | Wholesale & retail | 2011 |
| Midland Medical Services Limited | Construction | 1987 |
| Midland Power Press Services Limited | Manufacturing | 1989 |
| Midland Pristine Products Limited | Wholesale & retail | 2025 |
| Midland Records Ltd | Information & communication | 2021 |
| Midlands Pro-Seal Ltd | Construction | 2026 |
| Midlands Trading Solutions Ltd | Wholesale & retail | 2020 |
| Mihai Driving Ltd | Transport & logistics | 2017 |
| Mika Clinic Ltd | Other services | 2023 |
| Mikes Poultry Limited | Manufacturing | 2013 |
| Millennium Midland Ltd | Manufacturing | 2020 |
| Millie Services Limited | Administrative & support | 2016 |
| Milton Main Services Ltd | Other services | 2022 |
| Milton Main Trading Ltd | Wholesale & retail | 2022 |
| Minciuna Ltd | Transport & logistics | 2020 |
| Mind Full Coaching Ltd | Wholesale & retail | 2009 |
| Misibeth Global Ventures Limited | Health & social care | 2014 |
| Mission K9 Security Ltd | Other services | 2022 |
| MJ GAS Heating & Repair Ltd | Construction | 2021 |
| MJA Woods Ltd | Other services | 2016 |
| MLA Investment Company 01 Ltd | Health & social care | 2025 |
| Mlynello Ltd | Transport & logistics | 2024 |
| Mobeth Care Limited | Health & social care | 2024 |
| Mobile Base (B'Ham) Limited | Information & communication | 2017 |
| Mocandy Limited | Administrative & support | 2023 |
| Modern Synergy Ltd | Professional & scientific | 2025 |
| Modlit Holdings Limited | Professional & scientific | 1997 |
| Modlit Limited | Construction | 1944 |
| Modlit Precision Tooling Limited | Manufacturing | 1997 |
| Modular Kitchens Ltd | Construction | 2021 |
| Modular Maintenance Services Ltd | Construction | 2020 |
| Modusafe Ltd | Manufacturing | 2025 |
| Mogul Effect CIC | Education | 2024 |