| Mistry NDT Ltd | Professional & scientific | 2022 |
| Mitchell OIL Company Limited | Wholesale & retail | 1988 |
| Mitchell Renovations Ltd | Construction | 2015 |
| Mitsubishi Electric Iconics Digital Solutions UK Ltd | Information & communication | 1996 |
| Mixorchicken Ltd | Hospitality | 2021 |
| MJ & Sons Capital Ltd | Financial services | 2023 |
| MJ & Sons Holdings Ltd | Real estate | 2019 |
| MJ Digaway Ltd | Transport & logistics | 2020 |
| MJG Dudley Limited | Real estate | 2020 |
| MJR Services Limited | Construction | 1982 |
| Mjru Properties Limited | Real estate | 2026 |
| MJS Thermotest Limited | Wholesale & retail | 2024 |
| MKA Internet Retailer Limited | Wholesale & retail | 2024 |
| MLE Footcare Limited | Health & social care | 2025 |
| MLJ Advisory UK Ltd | Professional & scientific | 2025 |
| MLW V Ltd | Education | 2019 |
| MM Hospitality Services Ltd | Hospitality | 2026 |
| MM Supreme Cleaning Services Limited | Administrative & support | 2024 |
| Mmas Holdings Ltd | Financial services | 2023 |
| MN Car Body Repairs Ltd | Wholesale & retail | 2023 |
| Mnnh Limited | Real estate | 2026 |
| MO Cuts Ltd | Other services | 2026 |
| Mobi Techno Repairs Ltd | Wholesale & retail | 2018 |
| Mobile Arena Distribution Ltd | Wholesale & retail | 2023 |
| Mobile Arena Gadgets Ltd | Wholesale & retail | 2019 |
| Mobile Awareness Products Limited | Wholesale & retail | 2018 |
| Modena Properties Limited | Hospitality | 2008 |
| Modern Fast Foods Ltd | Hospitality | 2024 |
| Modern View Limited | Construction | 2025 |
| Mojiire Ltd | Wholesale & retail | 2026 |
| Moka Holdings Ltd | Wholesale & retail | 2020 |
| Molinari Group Holdings Ltd | Financial services | 2026 |
| Molineux Building Solutions Limited | Construction | 2009 |
| Mollybella Properties Limited | Real estate | 2019 |
| Momentum Planning & Consultancy Ltd | Professional & scientific | 2014 |
| Mommasdealsuk Ltd | Wholesale & retail | 2022 |
| Monarch Access Services Limited | Administrative & support | 2023 |
| Monarch Training and Labour Supply Ltd | Administrative & support | 2025 |
| Money Investment Group Ltd | Professional & scientific | 2026 |
| Monmore Recycling Limited | Water & waste | 2009 |
| Moonbeck Limited | Wholesale & retail | 2014 |
| More Than Gears Limited | Professional & scientific | 2023 |
| Morefresh Limited | Wholesale & retail | 2003 |
| Morency Limited | Health & social care | 2006 |
| Moreton Management Services Limited | Administrative & support | 2015 |
| Morganpropertyventures Ltd | Professional & scientific | 2025 |
| Morlag Co Limited | Health & social care | 2026 |
| Morley & Sons Limited | Hospitality | 2025 |
| Morris Building Renovations Limited | Construction | 2021 |
| Morris GS Limited | Hospitality | 2025 |
| Morris Industries Ltd | Wholesale & retail | 2021 |
| Mortha Eats Ltd | Hospitality | 2026 |
| Mortha Halls of IVY Ltd | Real estate | 2019 |
| Mortha Properties Ltd | Real estate | 2021 |
| Mortha Recruitment Ltd | Administrative & support | 2025 |
| Mortha Wellness Ltd | Other services | 2025 |
| Moscu Ltd | Transport & logistics | 2018 |
| Moseley Brothers Limited | Manufacturing | 2009 |
| Moseley Luxury Stay Ltd | Real estate | 2025 |
| Moss Industrial Service Ltd | Manufacturing | 2024 |
| Motazone Limited | Wholesale & retail | 1996 |
| Motech Solutions Ltd | Information & communication | 2007 |
| Motion Films Limited | Information & communication | 2023 |
| Motion Movement Ltd | Information & communication | 2024 |
| Motley Throng Limited | Wholesale & retail | 2025 |
| Motorkare Ltd | Information & communication | 2026 |
| Motorley Limited | Other services | 2025 |
| Motorline Mids Ltd | Wholesale & retail | 2026 |
| Motorstop Ltd | Wholesale & retail | 2019 |
| Motorstop West Midlands Ltd | Wholesale & retail | 2024 |
| Movieversalfilm.Com Ltd. | Information & communication | 2016 |
| Mowgli's Dog & Cat Grooming Ltd | Other services | 2017 |
| Moya Saunas Ltd | Manufacturing | 2025 |
| MP Music Limited | Information & communication | 2024 |
| Mppm Group Ltd | Construction | 2022 |
| MPS Placements Ltd | Administrative & support | 2023 |
| MQ Merchant Ltd | Wholesale & retail | 2024 |
| MR Bagley Holdings Ltd | Financial services | 2026 |
| MR MR Food Ltd | Hospitality | 2026 |
| MR Solver Limited | Construction | 2025 |
| Mrduvetshome Ltd | Wholesale & retail | 2018 |
| MS Aims Ltd | Wholesale & retail | 2024 |
| MS. Lapis Consulting Ltd | Administrative & support | 2026 |
| MSG Holdings (Midlands) Ltd | Real estate | 2019 |
| MSH Stores Dudley Limited | Wholesale & retail | 2024 |
| MSS Tech Solutions Ltd | Information & communication | 2026 |
| MST (Holdings) Limited | Professional & scientific | 1941 |
| MTA Cars Ltd | Wholesale & retail | 2024 |
| MTF Holding Limited | Professional & scientific | 2014 |
| MTL Equipment Ltd | Construction | 2005 |
| Mubiz Limited | Wholesale & retail | 2026 |
| Mucklow & Harris Limited | Construction | 2016 |
| Mucklow & Harris Properties Limited | Construction | 2021 |
| Mucklow Hill Ltd | Real estate | 2025 |
| Mullany & Newman Media Services Ltd | Professional & scientific | 2015 |
| Mullany and Mason Property Services Limited | Real estate | 2026 |
| Mullarkey Services Ltd | Professional & scientific | 2024 |
| Multi Solutions Enterprises Limited | Wholesale & retail | 2025 |
| Mumbai Eatery Ltd | Hospitality | 2019 |
| Mushtaq and Sons Healthcare Limited | Wholesale & retail | 2023 |