| M&V Boutique Limited | Wholesale & retail | 2021 |
| M&Y Sports Ltd | Arts & recreation | 2025 |
| M-Loch Technology Ltd | Information & communication | 2022 |
| M-Tech Custom Gear Knobs Ltd | Professional & scientific | 2025 |
| M. & a. Cars (Leeds) Limited | Wholesale & retail | 2010 |
| M. J. Wild Golf Consultancy Limited | Other services | 2019 |
| M.A. Platt Limited | Manufacturing | 1952 |
| M.A. Professional Medical Services Limited | Health & social care | 2016 |
| M.A.Osman Limited | Health & social care | 2023 |
| M.Akhan Builders Limited | Construction | 2026 |
| M.C. Electrical Limited | Construction | 2002 |
| M.H.Ali Enterprise Ltd | Wholesale & retail | 2021 |
| M.Habib Ltd | Health & social care | 2018 |
| M.J.Goldman Limited | Professional & scientific | 2009 |
| M.L.S Fire & Electrical Installations Limited | Construction | 2019 |
| M.M.H.S Motors Ltd | Wholesale & retail | 2025 |
| M.Nield Construction Ltd | Construction | 2019 |
| M.Y. Paving Ltd | Construction | 2025 |
| M0 Liquidity on Demand Limited | Energy | 2019 |
| M1 Enterprises World Wide Ltd | Wholesale & retail | 2024 |
| M2 Hospitality Solutions Limited | Manufacturing | 2021 |
| M28 Motors Ltd | Wholesale & retail | 2026 |
| M2A Estates Limited | Construction | 2023 |
| M2EDGE Limited | Wholesale & retail | 2025 |
| M4PT Ltd | Information & communication | 2019 |
| M60 Pilates Ltd | Arts & recreation | 2024 |
| M62 Records Ltd | Information & communication | 2026 |
| MA & Brothers Convenience Stores Ltd | Wholesale & retail | 2011 |
| MA Driving School Ltd | Other services | 2023 |
| MA Estates NW Ltd | Real estate | 2023 |
| MA Oldham Ltd | Other services | 2014 |
| MA Residences Ltd | Real estate | 2026 |
| MAA Healthcare Services Ltd | Health & social care | 2025 |
| MAA Services Limited | Households | 2024 |
| Maahir Phone Bazaar Ltd | Wholesale & retail | 2025 |
| Maal Investments Ltd | Financial services | 2021 |
| Maar Healthcare Services Ltd | Health & social care | 2025 |
| Maas & Co Motors Ltd | Wholesale & retail | 2026 |
| Maayarose Ltd | Wholesale & retail | 2025 |
| MAB Solution Nationwide Ltd | Construction | 2021 |
| Mabel’S Caribbean Ltd | Hospitality | 2024 |
| Mabuza Courier Express Ltd | Transport & logistics | 2023 |
| MAC Cars Limited | Professional & scientific | 2016 |
| MAC Daid Developments Ltd | Construction | 2025 |
| MAC Engineers Limited | Professional & scientific | 2022 |
| MAC Medical Ltd | Public administration | 2024 |
| Mac-Cell UK Cosmetics Ltd | Wholesale & retail | 2019 |
| Mach-Tech Services Ltd | Other services | 2007 |
| Machine Fitness Limited | Wholesale & retail | 2014 |
| Machinery Leasing Ltd | Administrative & support | 2009 |
| Machomans Product Ltd | Wholesale & retail | 2026 |
| Macky's Professional NDT and Rope Access Ltd Services Limited | Mining & quarrying | 2025 |
| Maclan Limited | Financial services | 2015 |
| Maclan Property LLP | | 2015 |
| Macnaught Digital Ltd | Professional & scientific | 2018 |
| MAD Autos Ltd | Wholesale & retail | 2024 |
| MAD Hot Ltd | Real estate | 2018 |
| Made by Smile Limited | Extraterritorial | 2020 |
| Made With Love Designs Limited | Other services | 2011 |
| Madina Barbers Ltd | Other services | 2023 |
| Madina Grocers Ltd | Wholesale & retail | 2017 |
| Madina Grocery Ltd | Wholesale & retail | 2023 |
| Madina Mercy | Other services | 2012 |
| Madina Seeds | Other services | 2018 |
| Madni Promotors Limited | Arts & recreation | 2024 |
| Madrasah Consultancy CIC | Education | 2026 |
| MAG Groundworks Limited | Construction | 2020 |
| MAG Property and Investments Ltd | Households | 2020 |
| Magazin Romanesc Oldham Ltd | Wholesale & retail | 2024 |
| MAGENCIA444 Ltd | Wholesale & retail | 2022 |
| Magic Square Consulting Limited | Financial services | 2016 |
| Magic WOK (Manchester) Ltd | Hospitality | 2019 |
| Magnolia Property Holdings Ltd | Real estate | 2022 |
| Magodi Limited | Health & social care | 2017 |
| MAH Haulage Limited | Transport & logistics | 2015 |
| MAH Utilities Ltd | Professional & scientific | 2022 |
| Mahdi Barbers Ltd | Other services | 2021 |
| Mahdlo (Oldham Youth Zone) | Arts & recreation | 2009 |
| Maheer Digital Limited | Professional & scientific | 2025 |
| Maheercart Ltd | Wholesale & retail | 2024 |
| Maher Motors Oldham Ltd | Wholesale & retail | 2024 |
| Mahfuj Property Ltd | Real estate | 2024 |
| Mahmood Property's Ltd | Real estate | 2023 |
| Mahoss Ltd | Wholesale & retail | 2024 |
| Mahroof Locum Services Limited | Wholesale & retail | 2009 |
| Mahteen's Unisex Salon Limited | Other services | 2024 |
| Main Strategies Ltd | Real estate | 2023 |
| Mainshow Ltd | Professional & scientific | 2019 |
| Mairidyl Ltd | Professional & scientific | 2013 |
| Maison Mounteney Ltd | Real estate | 2025 |
| Maitri's Trade Ltd | Wholesale & retail | 2025 |
| Majella Ltd | Professional & scientific | 2023 |
| Majestic Events Limited | Hospitality | 2026 |
| Majestic Linens Ltd | Wholesale & retail | 2014 |
| Maji Productions Ltd | Information & communication | 2026 |
| Major Base Ltd. | Real estate | 2023 |
| Major Events Management (UK) Ltd | Health & social care | 2024 |
| MAK International Limited | Information & communication | 2018 |
| Make Connections Ltd | Construction | 2023 |
| Make ITT Rain Ltd | Manufacturing | 2025 |