| Mamu Baghna Ltd | Hospitality | 2025 |
| Management Services (NW) Ltd | Professional & scientific | 2015 |
| Manchester Aggregates and Muckaway Limited | Transport & logistics | 2025 |
| Manchester Airport Transfers Limited | Transport & logistics | 2026 |
| Manchester Cakes 7 Ltd | Wholesale & retail | 2021 |
| Manchester Commercial Aluminium Ltd | Wholesale & retail | 2024 |
| Manchester Construction Management Ltd | Construction | 2017 |
| Manchester Diocesan Association of Church Schools(The) | Education | 1904 |
| Manchester Diocesan Board of Education | Education | 1959 |
| Manchester Diocesan Board of Finance | Other services | 1918 |
| Manchester Diocesan Church House Company Limited(The) | Real estate | 1908 |
| Manchester Drinks Company Ltd | Wholesale & retail | 2005 |
| Manchester EAR Clinic Ltd | Health & social care | 2021 |
| Manchester Fire Compliance Limited | Other services | 2014 |
| Manchester Heart Ltd | Health & social care | 2025 |
| Manchester High Voltage Solutions Ltd | Professional & scientific | 2023 |
| Manchester Hot Tubs Ltd | Wholesale & retail | 2019 |
| Manchester International Seals Ltd | Wholesale & retail | 2024 |
| Manchester Mortgages Limited | Other services | 2020 |
| Manchester Moving Service Ltd | Transport & logistics | 2026 |
| Manchester Network Ltd | Other services | 2018 |
| Manchester Plant Training Limited | Construction | 2020 |
| Manchester Road Community Centre | Health & social care | 2008 |
| Manchester Road Garage Ltd | Wholesale & retail | 2025 |
| Manchester Sports and Prestige Limited | Wholesale & retail | 2014 |
| Manchester Survivors Choir CIC | Health & social care | 2024 |
| Manchester Tuition Centre Ltd | Hospitality | 2022 |
| Manchester Vehicles Limited | Wholesale & retail | 2021 |
| Manchester Washing Machine Hire Ltd | Administrative & support | 2026 |
| Manchesterairporttaxi-Uk Ltd | Transport & logistics | 2025 |
| Manemastery Ltd | Education | 2024 |
| Manes Systems Limited | Manufacturing | 2016 |
| Manha Zirwa Ltd | Information & communication | 2026 |
| Manj Express Food Ltd | Hospitality | 2019 |
| Mankind Carrier Limited | Hospitality | 2017 |
| Mannat (MCR) Ltd | Wholesale & retail | 2024 |
| Mannion Properties Limited | Real estate | 2022 |
| Manor Care Services Ltd | Administrative & support | 2024 |
| Manor ST Garage Ltd | Wholesale & retail | 2018 |
| Manson Distribution Limited | Hospitality | 2013 |
| Mansoor Properties Limited | Real estate | 2025 |
| Mantac Ltd | Extraterritorial | 2021 |
| Mantos International Food Ltd | Wholesale & retail | 2020 |
| Mantty Ltd | Information & communication | 2025 |
| MAP HR Ltd | Administrative & support | 2017 |
| MAP Properties (North West) Ltd | Real estate | 2021 |
| MAR Automotive Ltd | Wholesale & retail | 2026 |
| Maranex Ltd | Wholesale & retail | 2025 |
| Marcot Flooring Solutions Ltd | Construction | 2013 |
| Margaret Haes Riding Centre Ltd | Arts & recreation | 2004 |
| Margolis Building Management Limited | Households | 2007 |
| Mario Bomfim Hair & Beauty Salon Ltd | Other services | 2019 |
| Marjoki Limited | Wholesale & retail | 2026 |
| Mark Anthony Dental Maintenance Limited | Administrative & support | 2008 |
| Mark Aziz Limited | Manufacturing | 2007 |
| Mark Colman Consulting Ltd | Real estate | 2020 |
| Mark Pearson HGV Driving Services Limited | Agriculture & fishing | 2017 |
| Mark Worthington Joinery Limited | Construction | 2008 |
| Markaz-Al-Huda Limited | Administrative & support | 2006 |
| Market Reech Consultancy Limited | Professional & scientific | 2026 |
| Marketingbymlb Ltd | Professional & scientific | 2022 |
| Marlborough Technologies Limited | Wholesale & retail | 2015 |
| Marquee Wealth Management Limited | Financial services | 2015 |
| Marquise Wellness Limited | Wholesale & retail | 2015 |
| Marsden and Co (Bury) Limited | Extraterritorial | 2015 |
| Marsha Care Services Limited | Health & social care | 2020 |
| Marshall Accounting Limited | Professional & scientific | 2026 |
| Marshall Wealth Limited | Financial services | 2023 |
| Marshalls Developments Ltd | Real estate | 2007 |
| Marshalls Haulage Ltd | Transport & logistics | 2025 |
| Marshallstrading Ltd | Wholesale & retail | 2025 |
| Martin & Taylor Engineers Limited | Manufacturing | 1962 |
| Martin Lawless Limited | Professional & scientific | 2012 |
| Martin's English School Ltd | Education | 2010 |
| Martini's Hospitality Ltd | Hospitality | 2024 |
| Martins Countryside Contracting Limited | Administrative & support | 2002 |
| Martono Ltd | Administrative & support | 2018 |
| Martrad Limited | Financial services | 1987 |
| Marva Digital Limited | Professional & scientific | 2025 |
| Marwood Solutions Limited | Extraterritorial | 2021 |
| Mary Edwards Therapeutic Education Limited | Education | 2023 |
| Mary Ruth Therapeutic Services Limited | Health & social care | 2023 |
| Maryella Ltd | Construction | 2019 |
| MAS Recovery Ltd | Transport & logistics | 2025 |
| Masad Properties Ltd | Real estate | 2017 |
| Mason Cole Wealth Management Limited | Financial services | 2019 |
| Masons House Property Services Limited | Real estate | 2022 |
| Masr Dental Ltd | Health & social care | 2023 |
| Masr Holdings Ltd | Financial services | 2025 |
| Masr Properties Ltd | Real estate | 2025 |
| Master Cheff Ltd | Hospitality | 2024 |
| Master Confectionery Ltd | Manufacturing | 2025 |
| Master Recruitment (UK) Ltd | Administrative & support | 2018 |
| Masterbranduk Ltd | Wholesale & retail | 2024 |
| Matcraft Ltd | Construction | 2025 |
| Matdev Limited | Financial services | 2025 |
| Matisse Advisory Limited | Information & communication | 2019 |
| Matisse Media Ltd | Information & communication | 2018 |
| Matisse Portfolio Limited | Information & communication | 2019 |
| Mats Direct Limited | Extraterritorial | 1997 |