| MCB Fabrications Limited | Manufacturing | 2001 |
| Mccarthy Bennett Holland Solicitors LLP | | 2020 |
| Mccarthy Heating Ltd | Construction | 2013 |
| Mcclad Ltd | Construction | 2021 |
| Mcconomy & Co.Limited | Wholesale & retail | 1933 |
| Mcdiamond Property Limited | Real estate | 2017 |
| Mcelchare Site Services Ltd | Transport & logistics | 2006 |
| MCG Auto Repairs Ltd | Wholesale & retail | 2016 |
| Mcgee Housing Ltd | Real estate | 2017 |
| Mcgill Consult Ltd | Professional & scientific | 2018 |
| Mcgills Restorations Ltd | Households | 2020 |
| Mcginty Demack Limited | Professional & scientific | 2013 |
| MCJ Electrical Contracting Ltd | Construction | 2011 |
| Mckee Associates Limited | Professional & scientific | 2006 |
| Mckenzie Electrical Ltd | Construction | 2026 |
| Mckenzie Private Constructs Ltd | Construction | 2025 |
| Mclivery Limited | Professional & scientific | 2019 |
| Mcmath Limited | Agriculture & fishing | 2007 |
| Mcneill Cleaning Services Ltd | Administrative & support | 2006 |
| Mcnulty Shoes Limited | Wholesale & retail | 2011 |
| Mcporsche Limited | Administrative & support | 2014 |
| MCR Elite Running Ltd | Education | 2022 |
| MCS (NW) Limited | Health & social care | 2016 |
| Mctucky's Ltd | Hospitality | 2016 |
| MCV Management Ltd | Administrative & support | 2019 |
| MD Business Interiors Devon Ltd | Construction | 2013 |
| MD Education Ltd | Health & social care | 2015 |
| MD Financial Accounting Limited | Professional & scientific | 2022 |
| MD Fitness & Coaching Ltd | Arts & recreation | 2024 |
| MD Plumbing and Heating (NW) Ltd | Construction | 2023 |
| MD Tattoo & Piercing Ltd | Arts & recreation | 2020 |
| MDC Technical Services Ltd | Manufacturing | 2024 |
| MDE Security Solutions Ltd | Construction | 2024 |
| MDH Asset Management Limited | Real estate | 2025 |
| Mdmt Homes Limited | Real estate | 2018 |
| MDS Property Solutions Limited | Construction | 2015 |
| MDT Plant Operator Ltd | Transport & logistics | 2018 |
| Meadow PIT Plant Hire Limited | Water & waste | 2003 |
| Meadows Boxing Ltd | Arts & recreation | 2026 |
| Meadowvale Electrical Services Limited | Professional & scientific | 2015 |
| Meazured Ltd | Wholesale & retail | 2023 |
| Mebono | Professional & scientific | 2023 |
| MEC Construction Estimating Ltd | Construction | 2011 |
| Mechspark Engineering Ltd | Professional & scientific | 2025 |
| Medallion Group Limited | Administrative & support | 1993 |
| Medapt Adaptive Products Limited | Wholesale & retail | 2025 |
| Media Cubs Ltd | Extraterritorial | 2020 |
| Mediascout Ltd | Information & communication | 2025 |
| Mediation Together Ltd | Other services | 2021 |
| Medical Education , Training and Clinical Services (Mets) Ltd | Education | 2025 |
| Medical Response Services Ltd | Administrative & support | 2017 |
| Medical Worker Limited | Health & social care | 2019 |
| Medico Chambers Limited | Health & social care | 2020 |
| Medikate Aesthetics Ltd | Health & social care | 2025 |
| Mediprocare Recruitments Ltd | Administrative & support | 2022 |
| Medusa Bar Ashton Ltd | Hospitality | 2024 |
| Medusa International Limited | Extraterritorial | 1999 |
| Medusa One Limited | Hospitality | 2025 |
| Meechan Properties Limited | Real estate | 2017 |
| Meekins Maintenance Limited | Water & waste | 2021 |
| Mees Radar Ltd | Professional & scientific | 2026 |
| Megamax Goods Ltd | Hospitality | 2024 |
| Megan's Manes Ltd | Other services | 2021 |
| Mehar Halal Meat Limited | Wholesale & retail | 2023 |
| MEK Electrical Ltd | Manufacturing | 2021 |
| Mekos Barber Shop Ltd | Other services | 2025 |
| Mel@Drama Limited | Arts & recreation | 2005 |
| Melasvesimo | Professional & scientific | 2025 |
| Meldon Gardens Management Company Limited | Households | 2015 |
| Melis Restaurant INT Ltd | Hospitality | 2025 |
| Melis Restaurant Ltd | Hospitality | 2024 |
| Melissa Edwards Studio Ltd | Other services | 2022 |
| Mellarius Ventures Ltd | Professional & scientific | 2026 |
| Melling Commercial Limited | Wholesale & retail | 2006 |
| Melling Property Holdings (Wigan) Ltd | Households | 2017 |
| Mellor Bridge Property Limited | Real estate | 2026 |
| Mellowmuse Ltd | Information & communication | 2012 |
| Melrah Property Services Ltd | Real estate | 2026 |
| Melrosa Marble & Granite Limited | Manufacturing | 2013 |
| Melrose Designs NW Ltd | Professional & scientific | 2025 |
| Melting POT Films Ltd | Information & communication | 2017 |
| Melwood Facilities Ltd | Professional & scientific | 2018 |
| Memorial Stones Direct Ltd | Wholesale & retail | 2025 |
| MEN of ALL Trades Ltd | Construction | 2017 |
| Men's Lobby Gidlow Lane Ltd | Other services | 2023 |
| Men's Lobby Ltd | Other services | 2022 |
| Mendez Global Ltd | Professional & scientific | 2026 |
| Menslobby City RD Limited | Other services | 2025 |
| Mentines | Professional & scientific | 2025 |
| Meraki B Ltd | Other services | 2025 |
| Merch Works Limited | Wholesale & retail | 2021 |
| MERCH360 Limited | Professional & scientific | 2024 |
| Mercury Digital Academy Ltd | Education | 2017 |
| Mercury Incentives Ltd | Administrative & support | 2022 |
| Mercury Mobile Solutions Limited | Information & communication | 2011 |
| Mercywins & Co Ltd | Health & social care | 2024 |
| Mereprop Limited | Real estate | 2023 |
| Meridian Consulting Ltd | Professional & scientific | 2026 |
| Meridian Hospitality Ltd | Hospitality | 2020 |
| Merrcury Digital Academy Ltd | Education | 2024 |