| Mighty Units Ltd | Manufacturing | 2025 |
| Mike Kershaw Consulting Ltd | Professional & scientific | 2012 |
| Mile Cross Garage Limited | Wholesale & retail | 2004 |
| Milius Transport Ltd | Transport & logistics | 2019 |
| Mill Barn Holdings Limited | Administrative & support | 2008 |
| Mill Field END Developments Ltd | Construction | 2015 |
| Mill Retail Limited | Information & communication | 2024 |
| Millhouse FM Ltd | Administrative & support | 2025 |
| Millhouse Furniture Makers Limited | Manufacturing | 2007 |
| Millhouse Waste Traders Limited | Wholesale & retail | 2021 |
| Milman Letta Ltd | Wholesale & retail | 2025 |
| MIM Financial Consulting Limited | Information & communication | 2022 |
| Mimshak Marvell Services Limited | Health & social care | 2023 |
| Mina Heritage Ltd | Real estate | 2026 |
| Mina's Table Limited | Hospitality | 2025 |
| Mindful ME Health & Well-Being Ltd | Education | 2009 |
| Mindologists Limited | Professional & scientific | 2018 |
| Minds CAN Limited | Health & social care | 2021 |
| Minds Matter Limited | Health & social care | 2017 |
| Minds Nebula Ltd | Professional & scientific | 2015 |
| Mindyerbusiness Limited | Professional & scientific | 2014 |
| Mindyerwealth Limited | Real estate | 2015 |
| Mineyoursours Ltd | Other services | 2026 |
| Minks Limited | Other services | 2019 |
| Minnervate Education Group Ltd | Financial services | 2025 |
| Minty Clean Ltd | Administrative & support | 2021 |
| Mirchi 360 Degrees Ltd | Hospitality | 2023 |
| Miriam Lois Limited | Other services | 2015 |
| Miscphrm Ltd | Health & social care | 2015 |
| Mishri Foods Limited | Manufacturing | 2015 |
| Mistry Maths Ltd | Education | 2014 |
| Misunderstood Ltd | Wholesale & retail | 2026 |
| Mitchell & Mitchell Management Ltd | Professional & scientific | 2016 |
| Mitchell Gray Consulting Limited | Professional & scientific | 2014 |
| Mitchell Mould Tools Limited | Manufacturing | 2026 |
| Mitchell-Brunt Limited | Information & communication | 2002 |
| Mititelu Delivery Ltd | Transport & logistics | 2025 |
| MJ10 Commerce Ltd | Wholesale & retail | 2024 |
| MJB Excavation & Plant Hire Ltd | Construction | 2009 |
| MJB Plant Hire & Excavations Ltd | Construction | 2009 |
| Mjelitemotors Limited | Wholesale & retail | 2024 |
| MJK Consultants Ltd | Information & communication | 2012 |
| MJR Decorating Services Ltd | Construction | 2020 |
| MJS Ward Investments Ltd | Financial services | 2025 |
| MJW Medical Limited | Health & social care | 2008 |
| MJW Property Maintenance Ltd. | Administrative & support | 2001 |
| MK Delights Limited | Wholesale & retail | 2015 |
| MK Transformations Ltd | Professional & scientific | 2024 |
| MK Videography Ltd | Information & communication | 2023 |
| MKA Pharm Ltd | Professional & scientific | 2022 |
| Mkc-Cair (UK) Ltd | Manufacturing | 1997 |
| MKH Networks Ltd | Information & communication | 2024 |
| Mkyri Ltd | Other services | 2018 |
| MLC Investments Limited | Real estate | 1995 |
| MLC Living Ltd | Real estate | 2025 |
| MLT Haulage Limited | Transport & logistics | 2025 |
| MM Traffic Solutions Ltd | Administrative & support | 2020 |
| MMA Holdings UK PLC | Financial services | 1999 |
| MMK Services Ltd | Transport & logistics | 2024 |
| MMS Store Ltd | Wholesale & retail | 2026 |
| MN Aesthetics Ltd | Other services | 2025 |
| MN Direct Ltd | Wholesale & retail | 2018 |
| MN Fabrication Services Limited | Manufacturing | 2014 |
| MNI Medical Ltd | Health & social care | 2023 |
| MNS Distribution Limited | Wholesale & retail | 2025 |
| Mntslettings Ltd | Real estate | 2025 |
| Mobile Express Ltd | Wholesale & retail | 2021 |
| Modern Modesty Limited | Wholesale & retail | 2025 |
| Modern Signs Digital Limited | Professional & scientific | 2011 |
| Modern Sushi Ancoats Limited | Hospitality | 2025 |
| Mog&Pepperdesigns Limited | Arts & recreation | 2018 |
| Mogul Search Ltd | Financial services | 2020 |
| Moh's Indian Take - Away Ltd | Hospitality | 2023 |
| Mohammed Healthcare Ltd | Health & social care | 2022 |
| Mojomarmitio Ltd | Information & communication | 2025 |
| Mokosz Ltd | Financial services | 2025 |
| Moli Group Ltd | Construction | 2019 |
| Moll'E Property Holdings Limited | Real estate | 2026 |
| Moll'Edent Limited | Professional & scientific | 2006 |
| Molly Madge Limited | Health & social care | 2014 |
| Moments by QR Ltd | Other services | 2024 |
| Momin Speciality Foods UK Ltd | Manufacturing | 2013 |
| Monaco Properties Limited | Construction | 2022 |
| Monarch Drives and Patios Ltd | Construction | 2023 |
| Money Cartel Limited | Wholesale & retail | 2020 |
| Money Link Money Transfer Ltd | Administrative & support | 2024 |
| Monnik Limited | Real estate | 2021 |
| Monti Transport Ltd | Transport & logistics | 2024 |
| Moofy Ltd | Construction | 2023 |
| Moon and Roses Ltd | Manufacturing | 2023 |
| Moor Consultancy Services Ltd | Professional & scientific | 2023 |
| Moor END Residential Ltd | Households | 2026 |
| Moor Hill Management Company Limited | Real estate | 2000 |
| Moorcroft Business Services Ltd | Administrative & support | 2022 |
| Moore & Starr Ltd | Professional & scientific | 2020 |
| Moorend Garage Limited | Wholesale & retail | 2012 |
| Moorhouse Electrical Contractors Ltd | Construction | 2015 |
| Moorlands Weddings & Events Ltd | Hospitality | 2023 |
| Moorside Garage (Halifax) Limited | Wholesale & retail | 2013 |
| Moorside Properties Limited | Construction | 1997 |