| MAP IT Group Ltd | Financial services | 2017 |
| Mappleton House Care Homes Limited | Health & social care | 2006 |
| March of WAR Ltd | Manufacturing | 2023 |
| Mark Brewster Limited | Professional & scientific | 2014 |
| Mark Toms Limited | Administrative & support | 2003 |
| Marlesahead Ltd | Education | 2026 |
| Martin Buchanan Plumbing & Heating Services Limited | Construction | 2003 |
| Martyn Young Properties Ltd | Real estate | 2022 |
| Marval Limited | Administrative & support | 2002 |
| Mason Bathrooms Ltd | Construction | 2020 |
| Mathsbox Limited | Education | 2014 |
| Matlock Construction Ltd | Extraterritorial | 2013 |
| Matlock Plant Hire Limited | Administrative & support | 2015 |
| Matthew Lewis Developments Limited | Construction | 2003 |
| Maxel Contract Services Limited | Administrative & support | 2007 |
| Maximo Properties Ltd | Real estate | 2019 |
| Maximobile Platform Services (UK) Limited | Administrative & support | 2025 |
| Maxis CNC Ltd | Manufacturing | 2024 |
| Mayers Design Ltd | Professional & scientific | 2008 |
| Mayfield 1958 Limited | Extraterritorial | 2013 |
| MAZ Asset Management Ltd. | Hospitality | 2024 |
| MB Digital Publishing Ltd | Other services | 2021 |
| Mbst Properties Ltd | Real estate | 2024 |
| Mccord Development Ltd | Real estate | 2019 |
| Mcdonald Junor Properties Ltd | Real estate | 2019 |
| Mcghee & Bowyer Holdings Limited | Real estate | 2020 |
| Mcghee Holdings Limited | Financial services | 2018 |
| Mcghee Investments Limited | Financial services | 2020 |
| Meadowbank Management Company Belper Limited | Households | 2018 |
| Meadowhay Promotions Ltd | Real estate | 2021 |
| Meadows Energy Services Limited | Extraterritorial | 2012 |
| Meadows Property Limited | Real estate | 2019 |
| Meaningfully Limited | Arts & recreation | 2024 |
| Mearsashby Road 1959 Limited | Extraterritorial | 2013 |
| Medicare Medical Ltd | Health & social care | 2026 |
| Meditex Medical Limited | Manufacturing | 2026 |
| Mellor Buglione Properties Limited | Construction | 2026 |
| Melscott Limited | Financial services | 2019 |
| Metals and Alloys Technical Advisory & Strategy Consultants Limited | Professional & scientific | 2025 |
| MFB Catering Limited | Hospitality | 2019 |
| Mfl.C Property Management Limited | Extraterritorial | 2021 |
| MG Mobile Mechanics Limited | Manufacturing | 2021 |
| MG Taylor Fuels Ltd | Wholesale & retail | 2026 |
| MGM Homes Limited | Construction | 2006 |
| MHG Holdings Group Limited | Financial services | 2025 |
| Mick Waumsley Consultant Limited | Professional & scientific | 2015 |
| Mickeyblu Travel Limited | Extraterritorial | 2003 |
| Mickleover Property Solutions & Developments Ltd | Real estate | 2026 |
| Microservice Solutions Ltd | Information & communication | 2020 |
| Midlands Political Services Limited | Professional & scientific | 2024 |
| Midlands Safety Ltd | Education | 2020 |
| Midlands Swim School Limited | Education | 2011 |
| Midlands Vehicle Diagnostics Ltd | Extraterritorial | 2020 |
| Midlec Limited | Construction | 2002 |
| Midshire Development Limited | Professional & scientific | 2003 |
| Milford Care Limited | Health & social care | 1995 |
| Milford Mills Hydro Limited | Energy | 2015 |
| Milford Munchies Ltd | Hospitality | 2025 |
| Mill Technologies Limited | Mining & quarrying | 2010 |
| Millard Electrical Contractors Ltd | Construction | 2018 |
| Millshaw Upholstery Ltd | Manufacturing | 2026 |
| Mindkeys Consulting Limited | Health & social care | 2025 |
| Mint Driving School Ltd | Education | 2007 |
| Mirkwood Restoration Ltd | Construction | 2026 |
| Missing Element Mortgage Services Limited | Financial services | 2006 |
| Mission Based Media Ltd | Administrative & support | 2019 |
| Mitch Town Consulting Ltd | Professional & scientific | 2021 |
| MJC Building Management Limited | Construction | 2018 |
| MLB Transformation Ltd | Information & communication | 2024 |
| MLD GAS & Plumbing Services Limited | Construction | 2013 |
| MLM Construction Services Ltd | Wholesale & retail | 2018 |
| MM Assistance Ltd | Construction | 2023 |
| MMR Traders Limited | Wholesale & retail | 2021 |
| MN Marketing Limited | Professional & scientific | 2013 |
| Mobile Attractions Limited | Arts & recreation | 2025 |
| Modis Consulting Ltd | Information & communication | 2023 |
| Mojo Art Ltd | Education | 2019 |
| Monkey Puzzle 9 Ltd | Real estate | 2022 |
| Monkey Puzzle Developments 5 Limited | Real estate | 2020 |
| Monkey Puzzle Developments 6 Limited | Real estate | 2020 |
| Monkey Puzzle Developments 7 Ltd | Real estate | 2021 |
| Monkey Puzzle Developments Project 1 Ltd | Real estate | 2017 |
| Monkey Puzzle Developments Project 2 Ltd | Real estate | 2017 |
| Monkey Puzzle Developments Project 3 Limited | Real estate | 2018 |
| Monkey Puzzle Developments Project 4 Ltd | Real estate | 2019 |
| Monki DO Limited | Arts & recreation | 2011 |
| Monsell Contracting Limited | Professional & scientific | 2014 |
| Montrose HR Limited | Professional & scientific | 2018 |
| Montys Transport Ltd | Transport & logistics | 2023 |
| Moochers Cafe-Lounge Ltd | Hospitality | 2025 |
| Moor Group Limited | Construction | 2017 |
| Moorgreen Peas Limited | Professional & scientific | 1980 |
| Morley Veterinary Practice Limited | Professional & scientific | 2016 |
| Moscow Farm Court Management Company Limited | Households | 1995 |
| Motlib Investments Ltd | Real estate | 2023 |
| Moto Mews Ltd | Transport & logistics | 2024 |
| Motorsave of Derby Limited | Wholesale & retail | 2003 |
| Mppy UK Limited | Real estate | 2024 |
| MPS (2020) Limited | Professional & scientific | 2020 |
| MS & SJ Bott Limited | Wholesale & retail | 2021 |