| MC Pro Clean Services Ltd | Administrative & support | 2025 |
| MC Quality Packing Limited | Manufacturing | 2017 |
| MC Quote Limited | Administrative & support | 2025 |
| MCI Direct Ltd | Health & social care | 2015 |
| Mckenzie & Ajimal Holdings Ltd | Real estate | 2024 |
| Mclaggan's Ltd | Wholesale & retail | 2022 |
| MCR Travel Ltd | Transport & logistics | 2018 |
| MDR Construction & Building Limited | Wholesale & retail | 2024 |
| MDS Engineering (West Midlands) Limited | Manufacturing | 2007 |
| MDX Ventures Limited | Financial services | 2025 |
| Meade Healthcare Ltd | Health & social care | 2022 |
| Meat UP Grill Ltd | Hospitality | 2026 |
| Mechcom Ltd | Professional & scientific | 2019 |
| MED Hero Ltd | Professional & scientific | 2026 |
| Meded by SU Ltd | Health & social care | 2025 |
| Medi-Zen Healthcare Services Limited | Wholesale & retail | 2013 |
| Medical Biometry Diagnostics Ltd | Information & communication | 2025 |
| Medina Fruit &VEG Limited | Hospitality | 2025 |
| Mehar Construction Ltd | Construction | 2020 |
| Memento Skin Clinic Limited | Other services | 2011 |
| Mental Fortitude C.I.C. | Administrative & support | 2024 |
| Mepcom Limited | Professional & scientific | 2015 |
| Mercer Property Midlands Ltd | Households | 2025 |
| Merchant Showroom Ltd | Wholesale & retail | 2021 |
| Mercia Healthcare Services Limited | Wholesale & retail | 2022 |
| Mercy Afro Harvest Limited | Wholesale & retail | 2026 |
| Merlin Accountancy & Payroll Services Ltd | Professional & scientific | 2006 |
| Merlin Electrical Supplies Ltd | Manufacturing | 2021 |
| Merlin Holdings WM Ltd | Real estate | 2017 |
| Merveldt Ltd | Administrative & support | 2017 |
| Metpro Limited | Wholesale & retail | 1993 |
| Mews Investments Limited | Construction | 2016 |
| Mfrr Ltd | Other services | 2022 |
| Miahs Vehicle Solutions Ltd | Wholesale & retail | 2022 |
| Mic's Landscape & Maintenance Limited | Administrative & support | 2025 |
| Micaline Electrical Systems Limited | Manufacturing | 1990 |
| Micaline HWW Ltd | Manufacturing | 2016 |
| Michaelorry Ltd | Transport & logistics | 2014 |
| Micharon Homes Limited | Construction | 2013 |
| Micheal Nails Ltd | Other services | 2026 |
| Michelle & Co Properties Ltd | Real estate | 2018 |
| Micro Drive Controls Limited | Manufacturing | 2003 |
| Micro Environmental Limited | Professional & scientific | 2017 |
| Micro Property Investments Ltd | Real estate | 2021 |
| Mida Commercials Ltd | Wholesale & retail | 2015 |
| Midland Assess Energy Limited | Professional & scientific | 2008 |
| Midland Engineering Ventures Limited | Wholesale & retail | 2024 |
| Midland Equestrian Ltd | Wholesale & retail | 2016 |
| Midland Export Packing Provider Limited | Administrative & support | 2021 |
| Midland Fibre Ltd | Information & communication | 2022 |
| Midland Health Care Services Limited | Health & social care | 2022 |
| Midland Pet Supplies Limited | Wholesale & retail | 2014 |
| Midland Sprinter Specialist Limited | Wholesale & retail | 2021 |
| Midland Vehicle Fleet Tracking Ltd | Wholesale & retail | 2022 |
| Midland Vent & Canopy Services Ltd | Construction | 2026 |
| Midlands Associates Limited | Transport & logistics | 2012 |
| Midlands Beds & Mattresses Ltd | Wholesale & retail | 2023 |
| Midlands Building Contractors Ltd | Construction | 2007 |
| Midlands Campers Ltd | Wholesale & retail | 2023 |
| Midlands Carriers Ltd | Transport & logistics | 2025 |
| Midlands Dyno Centre Ltd | Wholesale & retail | 2024 |
| Midlands EAR Care Limited | Health & social care | 2022 |
| Midlandwide Limited | Real estate | 2003 |
| Midnight Video Co. Ltd | Information & communication | 2023 |
| Midwest Lemforder Limited | Professional & scientific | 1989 |
| Mightysafe Caravan Storage Limited | Other services | 2017 |
| Mightysafe Containers (Wednesbury) Limited | Administrative & support | 2015 |
| Milestone Executive Travel Ltd | Transport & logistics | 2022 |
| Millingtons Building and Renovations Ltd | Construction | 2026 |
| Mills Project Management Ltd | Professional & scientific | 2023 |
| Mindflex Therapy Ltd | Other services | 2022 |
| Missing Link Support Ltd | Health & social care | 2023 |
| Mitsu Construction Company Ltd | Construction | 2021 |
| Mitsu Property Development Group Ltd | Real estate | 2023 |
| Mj's Bar & Venue Limited | Hospitality | 2017 |
| MJW Services WM Ltd | Construction | 2026 |
| MJW West Midlands Limited | Construction | 2016 |
| MK 1 Paints Ltd | Manufacturing | 2008 |
| Mkaeli Limited | Wholesale & retail | 2026 |
| MM Maddog Ltd | Information & communication | 2025 |
| MMC Foods (MAN Must Chop) Ltd | Hospitality | 2024 |
| MML Heathcare Ltd | Health & social care | 2026 |
| Mobiles Care Limited | Wholesale & retail | 2014 |
| Mode ICT Solutions Limited | Information & communication | 2025 |
| Modern Heating Solutions Limited | Wholesale & retail | 2023 |
| Modesque Ltd | Wholesale & retail | 2021 |
| Moga Delivery Ltd | Transport & logistics | 2024 |
| Moja Foods Limited | Hospitality | 2024 |
| Montana Drywall Limited | Construction | 2025 |
| MOONBASE66 Ltd | Wholesale & retail | 2026 |
| Moorcroft Projects Limited | Professional & scientific | 2025 |
| Moores Upholstery Limited | Manufacturing | 2016 |
| MOP Enterprises Limited | Administrative & support | 2025 |
| Morris Coffee Cafe Ltd | Hospitality | 2025 |
| MOT Depot Limited | Wholesale & retail | 2023 |
| Motofleet Limited | Transport & logistics | 2026 |
| Motorbykebitz Limited | Wholesale & retail | 2015 |
| Motorbykebitz Parts Ltd | Wholesale & retail | 2025 |
| Motorworld WM Ltd | Wholesale & retail | 2017 |
| Moxley Motor Repairs Ltd | Wholesale & retail | 2023 |