| Mindmybody Psychotherapy Limited | Health & social care | 2014 |
| Mindseye Development CIC | Administrative & support | 2021 |
| Mini Milestones Ltd | Administrative & support | 2023 |
| Mini Z and ME Group Ltd | Education | 2026 |
| Minthis Limited | Hospitality | 2025 |
| Minworth Engineering & Construction Ltd | Manufacturing | 2022 |
| Minworth Green Business Centre Limited | Real estate | 2019 |
| Minworth Industrial Estates Ltd | Real estate | 2015 |
| Minworth Property UK Limited | Real estate | 2012 |
| Minworth Sushi Ltd | Hospitality | 2020 |
| Minworth Vehicle Services Ltd | Wholesale & retail | 2023 |
| Miqi Ltd | Administrative & support | 2006 |
| MIR Medical Services Ltd | Health & social care | 2026 |
| Mirror Glass Media Ltd | Information & communication | 2024 |
| Mirza BEG Birmingham Ltd | Hospitality | 2025 |
| MIS Foot Limited | Health & social care | 2020 |
| Mis-Cellaneous Collective: Building Confidence Through Theatre CIC | Education | 2025 |
| Mishra Medicals Ltd | Health & social care | 2025 |
| Mismile Recruitment Ltd | Administrative & support | 2025 |
| Miss Tailor Birmingham Ltd | Wholesale & retail | 2019 |
| Missi-Mac Ltd | Manufacturing | 2025 |
| Mitchel LEE and Partners Limited | Financial services | 2019 |
| Mitchell Butchers Ltd | Wholesale & retail | 2012 |
| Mitchell Court Management Company Limited | Real estate | 2004 |
| Mitchell Shoesmith Ltd | Education | 2018 |
| MJ13 Homes Limited | Real estate | 2026 |
| MJ13 Properties Limited | Real estate | 2023 |
| MJA 23 Ltd | Administrative & support | 2021 |
| Mjbenn Limited | Financial services | 2025 |
| MJC Contracting Ltd | Professional & scientific | 2026 |
| MJD Consulting Solutions Ltd | Information & communication | 2023 |
| MJD Recruiting Ltd | Administrative & support | 2024 |
| Mjhz Developments Ltd | Construction | 2026 |
| MJM Advanced Solutions Limited | Extraterritorial | 2011 |
| Mjma Ltd | Real estate | 2014 |
| Mjmorris Leisure Ltd | Hospitality | 2018 |
| MJT Roofing Ltd | Construction | 2019 |
| MK Hair and Beauty Salon Limited | Other services | 2019 |
| MK Strategy Limited | Real estate | 2013 |
| Mk's Housing Ltd | Real estate | 2023 |
| MKA25 Ltd | Real estate | 2025 |
| Mkmtb Ltd | Information & communication | 2026 |
| MKT Property Ltd | Real estate | 2019 |
| ML Aesthetics Ltd | Health & social care | 2024 |
| MLC LA Limited | Health & social care | 2024 |
| MLK Medical Limited | Health & social care | 2024 |
| MLM Search Partner Limited | Administrative & support | 2018 |
| MLP Couriers Ltd | Transport & logistics | 2021 |
| MLR Equestrian Ltd | Administrative & support | 2026 |
| MLS Accountancy Limited | Professional & scientific | 2017 |
| MMR Housing Ltd | Hospitality | 2025 |
| Mmrr Fish and Chips Ltd | Hospitality | 2025 |
| MNA Healthcare Ltd | Health & social care | 2025 |
| MNM Europe Limited | Real estate | 2026 |
| MNS 2021 Limited | Construction | 2025 |
| MO Building Inspection Services Ltd | Construction | 2025 |
| MOA Professional Educonsult Ltd | Professional & scientific | 2026 |
| Mobile Video Solutions Europe Ltd | Information & communication | 2019 |
| Mobile Wash Way Limited | Administrative & support | 2017 |
| Mode Conversions Limited | Manufacturing | 2024 |
| Modelo Properties Limited | Real estate | 2017 |
| Modern Adobe Ltd | Professional & scientific | 2023 |
| Modern Home Services Ltd | Real estate | 2021 |
| Modern Look Radiators Ltd | Wholesale & retail | 2023 |
| Modern Munch Ltd | Hospitality | 2024 |
| Modern Rattan Ltd | Wholesale & retail | 2021 |
| Modern Reserve Group Ltd | Professional & scientific | 2026 |
| Modiri Properties Limited | Real estate | 2018 |
| Mogb Ltd | Construction | 2025 |
| Moja Life Limited | Wholesale & retail | 2025 |
| Mojorain Ltd | Arts & recreation | 2002 |
| Moment Communications Limited | Professional & scientific | 2019 |
| Momentum Engineering Group Ltd | Financial services | 2020 |
| MON Shon Properties Limited | Real estate | 2019 |
| Mona Limited | Health & social care | 2021 |
| Monarch Restaurant Group (Great Barr) Ltd | Hospitality | 2021 |
| Monarch Restaurant Group (Wylde Green) Ltd | Hospitality | 2021 |
| Monest Shop Limited | Wholesale & retail | 2024 |
| Moneysworth Trading Limited | Administrative & support | 1999 |
| Montague SSA Limited | Financial services | 2024 |
| Montgomery Festivals Ltd | Arts & recreation | 2024 |
| Montgomery PUB Co Holdings Ltd | Hospitality | 2023 |
| Montgomery PUB Co Ltd | Hospitality | 2023 |
| Monumental Masons Limited | Extraterritorial | 1958 |
| Moody's Funeral Directors Limited | Extraterritorial | 1970 |
| Moomoocloud Limited | Information & communication | 2018 |
| Moonlight Grace Ltd | Other services | 2023 |
| Moonspice Ltd | Hospitality | 2019 |
| Moor Hall Developments Limited | Construction | 2013 |
| Moor Hall View Ltd | Real estate | 2024 |
| Moor Lane Self Storage Limited | Real estate | 2016 |
| Moorefield Farm Limited | Agriculture & fishing | 2018 |
| Moras Blinds Ltd | Manufacturing | 2023 |
| More Life Fitness Ltd | Arts & recreation | 2025 |
| More Than Therapy Active CIC | Health & social care | 2025 |
| Morecambe & Heysham Funeral Service Limited | Extraterritorial | 1978 |
| Morelands Properties Limited | Real estate | 2024 |
| Morgan Capital Holdings Ltd | Real estate | 2023 |
| Morgan Degville Property Management Limited | Real estate | 2013 |
| Morgan Technical Limited | Manufacturing | 2002 |