| Mercia Whisky Company Ltd | Manufacturing | 2020 |
| Mercian Forge Ltd | Education | 2015 |
| Mercy’S Caring Hands Ltd | Health & social care | 2020 |
| Metal Wizards Limited | Manufacturing | 2012 |
| Meters 2 U LLP | | 2018 |
| Meters and Gauges Calibration Limited | Professional & scientific | 2025 |
| Meticulous Automotive Performance Solutions (Maps) Limited | Wholesale & retail | 2019 |
| MF Woollard LLP | | 2023 |
| MIA Direct Group Holdings Ltd | Households | 2018 |
| MIA Direct Limited | Information & communication | 2016 |
| MIA Traffic Management Limited | Public administration | 2020 |
| MIA Training Limited | Construction | 2021 |
| MIA Utility Services Limited | Financial services | 2021 |
| MID Installations Limited | Construction | 2012 |
| Midcount Properties Limited | Real estate | 2025 |
| Midland & General Scaffolding Ltd | Construction | 2007 |
| Midland Caravan Storage Limited | Transport & logistics | 2024 |
| Midland GAS, Heating & Plumbing Ltd | Other services | 2016 |
| Midland Pipeline Supplies Limited | Administrative & support | 1993 |
| Midland Psychiatry & Psychology (Reports) Limited | Health & social care | 2014 |
| Midland Psychiatry and Psychology (Therapy) Ltd | Health & social care | 2014 |
| Midlands Air Source Ltd | Construction | 2022 |
| Midlands Medical Ltd | Health & social care | 2023 |
| Midlands Property Lettings Ltd | Real estate | 2026 |
| Midshires Ltd | Wholesale & retail | 1999 |
| Midway Electrical Services Ltd | Construction | 2011 |
| Midway Material Handling Ltd | Construction | 2007 |
| Milla Holdings Ltd | Real estate | 2025 |
| Mindstage Support Ltd | Education | 2025 |
| Minster Mews Management Company Limited | Households | 1991 |
| Mirrorstone Developments Ltd | Real estate | 2025 |
| Mitchell's Sports Promotions Limited | Arts & recreation | 2011 |
| Mitton Holdings Limited | Financial services | 2017 |
| MJ Byrne Ltd | Construction | 2025 |
| MJ Smith Holdings Ltd | Information & communication | 2024 |
| MJE People Solutions Limited | Professional & scientific | 2023 |
| MJM Plumbing Staffordshire Limited | Construction | 2024 |
| MKM Building and Lettings Ltd | Construction | 2025 |
| Mlec (UK) Limited | Manufacturing | 2005 |
| MLG Scaffolding Services Ltd | Construction | 2024 |
| MM Consulting Ltd | Professional & scientific | 2024 |
| MMP & Co Properties Ltd | Real estate | 2025 |
| MO 98 Studio Ltd | Other services | 2025 |
| Mobile Signs Ltd | Manufacturing | 2017 |
| Modern Touch Design & Build Ltd | Construction | 2023 |
| Moneram Limited | Real estate | 2002 |
| Monster Particles Limited | Arts & recreation | 2017 |
| Moor Croft Maintenance Limited | Real estate | 2004 |
| Mount Tyre Services Limited | Wholesale & retail | 2024 |
| Moyes Plumbing Supplies Ltd | Wholesale & retail | 2010 |
| MP Cleaning Solutions Ltd | Administrative & support | 2021 |
| MPW Safety Solutions Ltd | Education | 2014 |
| MRH CAD Solutions Limited | Professional & scientific | 2013 |
| MSP Derby Ltd | Arts & recreation | 2020 |
| Mtek Developments Limited | Manufacturing | 2017 |
| Muah (Lichfield) Ltd | Wholesale & retail | 2023 |
| Multitec Services Limited | Construction | 2015 |
| Muntz Family Holdings Ltd | Administrative & support | 2019 |
| Murphy Finance Limited | Financial services | 1995 |
| Must Bangladeshi and Indian Cuisine Ltd | Hospitality | 2018 |
| My Driver Group Limited | Transport & logistics | 2020 |
| My Little Minnow Ltd | Wholesale & retail | 2021 |
| My Own Gardener Ltd | Administrative & support | 2015 |
| My Own Hire and Service Ltd | Manufacturing | 2026 |
| Mycock Farming Ltd | Agriculture & fishing | 2018 |
| N & K Brown & SON Limited | Agriculture & fishing | 2024 |
| N Beaumont Holdings Limited | Financial services | 2019 |
| N E Hawthorne & SON Limited | Construction | 2010 |
| N J & E T Coles Limited | Wholesale & retail | 2002 |
| N Powell Electrical Limited | Construction | 2003 |
| N.S. Clarke Transport Limited | Transport & logistics | 2003 |
| Nailed-It Home & Garden Ltd | Construction | 2025 |
| Narawell Consultancy Ltd | Administrative & support | 2017 |
| Nateco Group Limited | Other services | 2014 |
| Nathire Limited | Other services | 2014 |
| Natstaff Limited | Other services | 2014 |
| Natural Air (UK) Limited | Construction | 2008 |
| Nature and Nurture Psychology Ltd | Other services | 2019 |
| Natwaste Limited | Water & waste | 2014 |
| Naymac Properties Limited | Households | 2025 |
| Neamas Ltd | Construction | 2025 |
| Neils Tyres Limited | Other services | 2020 |
| Neptune Bathrooms Walsall Limited | Construction | 2014 |
| Netherstowe Properties Ltd | Real estate | 2024 |
| Network UK Windows & Doors Ltd | Construction | 2023 |
| New 2 TRI Limited | Arts & recreation | 2016 |
| New Wire Energy Ltd | Construction | 2024 |
| New Wire Ltd | Construction | 2020 |
| Newstock LLP | | 2024 |
| Newtown Garages (Birmingham) Limited | Wholesale & retail | 1948 |
| Nexium Engineering Ltd | Construction | 2007 |
| Nexphase Consultants Ltd | Information & communication | 2005 |
| Nexus Digital Engineering Ltd | Professional & scientific | 2026 |
| NF Express Ltd | Transport & logistics | 2026 |
| Nhcomputing Ltd | Information & communication | 2012 |
| Nhrf Ltd | Professional & scientific | 2013 |
| Niche Creative Limited | Administrative & support | 2013 |
| Nick Turner Counselling Ltd | Health & social care | 2013 |
| Nikolov Ltd | Construction | 2018 |
| Nirmec Limited | Administrative & support | 1977 |