| Merry Hill Interiors Limited | Wholesale & retail | 2007 |
| Metal Fabrications & Laser Limited | Extraterritorial | 2024 |
| Metal Finishing Machines Limited | Manufacturing | 2009 |
| Metal for Good Trading Limited | Wholesale & retail | 2024 |
| Metal Process Technologies Ltd | Wholesale & retail | 2025 |
| Metalwork Installation Limited | Manufacturing | 2019 |
| Meter Services Ltd | Professional & scientific | 2024 |
| Mevlana Medical Limited | Health & social care | 2025 |
| Mezeo Ltd | Hospitality | 2026 |
| Mezzanine Innovations Limited | Construction | 1996 |
| MF Property Rental Ltd | Real estate | 2024 |
| MF Temporary Works Ltd | Professional & scientific | 2015 |
| MF Vehicle Consulting LLP | | 2020 |
| Mfm-It Holdings Limited | Financial services | 2022 |
| Mfm-It Limited | Information & communication | 2012 |
| Mfth Ltd | Real estate | 2023 |
| MG Calivia Property Limited | Real estate | 2025 |
| MGF Centre Cars Limited | Wholesale & retail | 2019 |
| MGF Centre Limited | Wholesale & retail | 2016 |
| MH Audio Ltd | Information & communication | 2026 |
| MH Autos Service & Repair Ltd | Wholesale & retail | 2025 |
| MHG Sales Limited | Wholesale & retail | 2025 |
| Mhml 1001 Limited | Construction | 2017 |
| MHT Property Group Limited | Real estate | 2025 |
| Mi:Skinbar Medical Aesthetics Limited | Health & social care | 2023 |
| Michael Davis Fitness Ltd | Other services | 2022 |
| Michael GAV Investments Ltd | Real estate | 2022 |
| Mick-Tarmac & Paving Limited | Construction | 2020 |
| Mickie Finns Ltd | Hospitality | 2022 |
| Microhotels Limited | Hospitality | 2022 |
| Micron Alloy Castings Limited | Manufacturing | 1989 |
| Micron Property Services Ltd | Real estate | 2024 |
| Microzone Limited | Extraterritorial | 2019 |
| Middle Acre Properties Limited | Real estate | 2018 |
| Middleton Scriven Investments Limited | Construction | 1976 |
| Midland Accountancy Solutions Ltd | Professional & scientific | 2023 |
| Midland Builder Group Ltd | Construction | 2026 |
| Midland Builders Group Ltd | Construction | 2016 |
| Midland Drain Solutions Limited | Water & waste | 2019 |
| Midland Health Recruitment Limited | Health & social care | 2020 |
| Midland Holloware Products Limited | Wholesale & retail | 2020 |
| Midland Optical Ltd | Manufacturing | 2017 |
| Midland Probate Services Ltd | Professional & scientific | 1989 |
| Midland Road Sweepers Ltd | Construction | 2006 |
| Midland Security & Surveillance Ltd | Administrative & support | 2012 |
| Midland Vaux Parts Limited | Professional & scientific | 2014 |
| Midland Wire Mesh Limited | Other services | 1975 |
| Midlands Assessments Limited | Health & social care | 2024 |
| Midlands Auto Motors Ltd | Wholesale & retail | 2023 |
| Midlands Building Services Ltd | Construction | 2023 |
| Midlands Furnishing Services Ltd | Construction | 2020 |
| Midlands I.T. Recycling Ltd | Manufacturing | 2012 |
| Midlands Sales Limited | Construction | 2020 |
| Midlands Traffic Management Holdings Ltd | Financial services | 2017 |
| Midlands Traffic Management Limited | Construction | 1994 |
| Midshire Scaffolding Midlands Company Limited | Construction | 2016 |
| Mighty Tight Records Ltd | Information & communication | 2014 |
| Mihai Mario Construct Ltd | Construction | 2022 |
| MIK Kitchen and Bedroom Limited | Manufacturing | 2025 |
| Mike Jassi Ltd. | Information & communication | 2017 |
| Mill Pool (Nash Lane) Management Company Limited | Real estate | 2007 |
| Millichip Properties Ltd | Real estate | 2025 |
| Millpond Limited | Professional & scientific | 1998 |
| Milton House (ACH) Limited | Health & social care | 2012 |
| Miltonrose Learning Ltd | Professional & scientific | 2026 |
| Mind the Monkeys Ltd | Health & social care | 2021 |
| Mindcalming Studio Ltd | Health & social care | 2024 |
| Mindful Life Counselling CIC | Administrative & support | 2020 |
| Mindful Life Therapies Limited | Administrative & support | 2023 |
| Mindquest Games Ltd | Information & communication | 2025 |
| Minerva Learning Limited | Professional & scientific | 2015 |
| Minley Developments Ltd | Construction | 2017 |
| Mint Deserts Limited | Hospitality | 2025 |
| Minton Accountancy Limited | Professional & scientific | 2019 |
| Miss Rose Limited | Professional & scientific | 2023 |
| Mister Heat Limited | Manufacturing | 2015 |
| Mitch Bellis Carpet & Flooring Limited | Construction | 2023 |
| Mitchell Building Services (Midlands) Ltd | Construction | 2014 |
| Mitigator Offroaden Ltd | Wholesale & retail | 2026 |
| Mitton Roofing Services Ltd | Construction | 2022 |
| Mixalos Media Ltd | Arts & recreation | 2025 |
| Mixd Reality Ltd | Information & communication | 2021 |
| Mixedup 2 Limited | Real estate | 2020 |
| MJ Linen House Ltd | Wholesale & retail | 2026 |
| MJ Plumbing & Heating Solutions Limited | Construction | 2025 |
| MJ Welding & Fabrication Ltd | Manufacturing | 2023 |
| MJ. Bagley Builders Ltd | Construction | 1999 |
| Mjcdev IT Consultancy Services Limited | Information & communication | 2016 |
| MJM Connect Ltd | Information & communication | 2023 |
| MJR Sales Ltd | Administrative & support | 2024 |
| MK Electrics (UK) Ltd | Construction | 2013 |
| MKG Group Limited | Other services | 2021 |
| MKM Events CIC | Hospitality | 2018 |
| MLA Homes (West Midlands) Limited | Real estate | 2023 |
| MLA Investment Limited | Real estate | 2016 |
| MLH Commercial Ltd | Real estate | 2024 |
| MM Soul (UK) Ltd | Manufacturing | 2020 |
| Mmmr Traders Ltd | Wholesale & retail | 2019 |
| MMP Homes Limited | Real estate | 2020 |
| Mobhutstourbridge Ltd | Wholesale & retail | 2023 |