| Mark Whittell Legal Services Limited | Professional & scientific | 2013 |
| Market Store Ltd | Wholesale & retail | 2025 |
| Marple Bridge Motor Company Limited | Wholesale & retail | 2003 |
| Marple Roofline Limited | Construction | 2016 |
| Marshall Wild Limited | Professional & scientific | 2008 |
| Masons Arms (New Mills) Ltd | Hospitality | 2024 |
| Mather Painting Contractors Ltd | Construction | 2017 |
| Matt Props Ltd | Information & communication | 2025 |
| Matt’S Attic Ltd | Hospitality | 2024 |
| Maverick Electrical Ltd | Construction | 2019 |
| Maverick Sales and Distribution Ltd | Professional & scientific | 2022 |
| MB Plant and Transport Ltd | Transport & logistics | 2022 |
| MBH Agencies Ltd | Administrative & support | 2020 |
| Mccracken Meek Property Developments Limited | Real estate | 2019 |
| MCF Solutions Ltd | Construction | 2010 |
| Mckeever & Partners Ltd | Professional & scientific | 2009 |
| Mclane Consulting LLP | | 2014 |
| MCP (Tideswell) Limited | Extraterritorial | 2010 |
| MDG Design Limited | Professional & scientific | 2011 |
| MDT Property Holdings Ltd | Real estate | 1997 |
| Meadow Joinery Services Ltd | Construction | 2023 |
| Meadow Lark Ltd | Real estate | 2024 |
| Meat Shack Shrewsbury Limited | Wholesale & retail | 2016 |
| Mediate North Limited | Professional & scientific | 2013 |
| MEL Hadfield Property Ltd | Real estate | 2025 |
| Memories of India (Whaleybridge) Ltd | Hospitality | 2024 |
| Merigan Ltd | Professional & scientific | 2020 |
| Metagenics UK Ltd | Wholesale & retail | 1984 |
| Metal Suppliers (UK) Limited | Wholesale & retail | 2018 |
| Metal Supplies Limited | Wholesale & retail | 2008 |
| Metamorphic Installations Limited | Construction | 2022 |
| Metra Limited | Mining & quarrying | 2001 |
| MG Aero Services Ltd | Manufacturing | 2011 |
| MH Transport Services Ltd | Transport & logistics | 1996 |
| Middle Earth Productions Limited | Arts & recreation | 2011 |
| Midland Relocation Ltd | Other services | 2017 |
| Midnight Audio Sanctuary Ltd | Arts & recreation | 2023 |
| Mighty Mouth Ltd | Information & communication | 2019 |
| Mike Cheyne Business Solutions Limited | Professional & scientific | 2009 |
| Miller Stone Properties Limited | Real estate | 2003 |
| Millfern Limited | Construction | 2018 |
| Millicent's Properties Ltd | Real estate | 2024 |
| Millwater Property Services Cheshire Limited | Construction | 2014 |
| Milnes Legal Group Ltd | Professional & scientific | 2017 |
| Minibus Options Limited | Administrative & support | 1986 |
| Misidore Limited | Education | 2020 |
| Mitchep Ltd | Professional & scientific | 2024 |
| MJ & S Homes Limited | Real estate | 2025 |
| MJF Advisory Limited | Professional & scientific | 2026 |
| MK Street Food Ltd | Hospitality | 2025 |
| MKC Tech Ltd | Information & communication | 2024 |
| MKL Decorating Limited | Construction | 2015 |
| MML Real Estate Ltd | Real estate | 2024 |
| MMM Bloodstock Ltd | Agriculture & fishing | 2026 |
| Mobius Pictures Limited | Information & communication | 2004 |
| Mode=Create Limited | Information & communication | 2017 |
| Monami Finance Ltd | Financial services | 2024 |
| Moorings Holdings Limited | Real estate | 2024 |
| Morgan Flooring Limited | Wholesale & retail | 2013 |
| Morgan-Ward (Non-Destructive Testing) Limited | Professional & scientific | 1973 |
| Morten Engineering Services Limited | Professional & scientific | 2026 |
| Mosswell Ltd | Professional & scientific | 2023 |
| Mount View Boarding Kennels Limited | Other services | 2003 |
| MPG Contractors Limited | Construction | 2022 |
| MPP Culture Limited | Professional & scientific | 2025 |
| Murgs Ltd | Wholesale & retail | 2021 |
| Mushana Property Investments Limited | Real estate | 2016 |
| Musicking Together High Peak CIC | Arts & recreation | 2025 |
| Mutuare Limited | Professional & scientific | 2014 |
| MW & AIT Holdings Ltd. | Professional & scientific | 2009 |
| MWF Autos Limited | Wholesale & retail | 2022 |
| MWH Asset Management Limited | Real estate | 2009 |
| Mwssales Ltd | Wholesale & retail | 2024 |
| My Functional Apothecary Ltd | Wholesale & retail | 2019 |
| My Ingredients Limited | Hospitality | 2012 |
| My Urban Trail Ltd | Wholesale & retail | 2021 |
| Myletter Ltd | Information & communication | 2025 |
| N G Bennett Joinery Ltd. | Construction | 2002 |
| N S S Holdings Limited | Financial services | 2017 |
| N.D.T. Maincal Limited | Manufacturing | 1988 |
| Natalie Leech Photography Limited | Professional & scientific | 2007 |
| Nationwide Fire Solutions Limited | Administrative & support | 2003 |
| Navy Sweets Limited | Extraterritorial | 1954 |
| NDT Personnel Limited | Administrative & support | 2016 |
| Neiman Packaging Limited | Manufacturing | 1981 |
| Nellrock Limited | Real estate | 2024 |
| Nevett & Taylor Limited | Financial services | 1974 |
| New Mills and District Volunteer Centre | Other services | 2003 |
| New Mills and Newtown Cricket and Athletic Club Company Limited | Arts & recreation | 1900 |
| New Mills Barbers Ltd | Other services | 2022 |
| New Mills Community Workshop CIC | Manufacturing | 2024 |
| New Mills Vapes Limited | Wholesale & retail | 2026 |
| New Mills Youth and Community Project C.I.C. | Public administration | 2020 |
| Nextgen Training Solutions Ltd | Education | 2020 |
| Nimbus Property Group Ltd | Construction | 2026 |
| NKF Catering Limited | Hospitality | 2019 |
| NKS Brothers Ltd | Hospitality | 2025 |
| NO Jobs in the Arts CIC | Arts & recreation | 2022 |
| Nomad Life Ltd | Wholesale & retail | 2019 |
| Northern Car Audio Limited | Wholesale & retail | 1997 |