| M J Beech Ltd | Information & communication | 2015 |
| M J Windows Limited | Construction | 2013 |
| M LAP Engineering Services Ltd | Professional & scientific | 2015 |
| M Plank Limited | Construction | 2005 |
| M S Partners Limited | Professional & scientific | 2012 |
| M S Property Partners Limited | Real estate | 2018 |
| M Y Future Ventures Ltd | Extraterritorial | 2013 |
| M&C C Holdings Limited | Transport & logistics | 2020 |
| M&K New Horizons Limited | Professional & scientific | 2015 |
| M. Harris Logistics Limited | Transport & logistics | 2011 |
| M.F.G. Estates Limited | Real estate | 2000 |
| M.R.S. (Automation) Limited | Professional & scientific | 1988 |
| M.Whalley Joinery Ltd | Construction | 2018 |
| M2M Data Connect Limited | Information & communication | 2018 |
| M4SON Limited | Wholesale & retail | 2023 |
| MAB Language Services Ltd | Professional & scientific | 2013 |
| Mackfoxel NOR Properties Limited | Real estate | 2024 |
| Mackie Project Consultants Ltd | Construction | 2020 |
| Macmaster Dean Limited | Administrative & support | 2013 |
| Maczs Ltd | Information & communication | 2007 |
| Made to Cook Ltd | Hospitality | 2023 |
| Made With MIA Ltd | Manufacturing | 2020 |
| Magic Journey Ltd | Wholesale & retail | 2025 |
| Magie Investments Limited | Professional & scientific | 2024 |
| Magill Project Management Limited | Professional & scientific | 2020 |
| Mahler Marrow Consulting Limited | Administrative & support | 2020 |
| MAID2CLEAN (EJE) Ltd | Administrative & support | 2021 |
| MAID2CLEAN (Franchise) Limited | Administrative & support | 2002 |
| MAID2CLEAN Homes Limited | Administrative & support | 2009 |
| MAID2CLEAN Houses Ltd | Administrative & support | 2011 |
| MAID2CLEAN Residences Ltd | Administrative & support | 2011 |
| MAID2CLEAN Warrington Limited | Other services | 2017 |
| Mais Innovation Ltd | Information & communication | 2025 |
| MAJ Team Ltd | Health & social care | 2024 |
| Makc Artisan Ltd | Manufacturing | 2022 |
| Make a Difference Activities LLP | | 2023 |
| Maleitus Ltd | Transport & logistics | 2022 |
| Malimara Limited | Wholesale & retail | 2020 |
| Maltix Ltd | Information & communication | 2019 |
| Mambo Agency Ltd | Professional & scientific | 2010 |
| MAN & Machine Groundworks Ltd | Extraterritorial | 2014 |
| MAN & the Echo Limited | Arts & recreation | 2015 |
| Manchester Gems Limited | Wholesale & retail | 2025 |
| Mang WU Limited | Real estate | 2022 |
| Mango B2B Limited | Wholesale & retail | 2018 |
| Mango Corporation Limited | Information & communication | 1997 |
| Manic Customs Limited | Wholesale & retail | 2021 |
| Manj Properties & Investments Limited | Real estate | 2022 |
| Mapesbury Road Residents Management Limited | Real estate | 1975 |
| Mapis Limited | Information & communication | 2023 |
| Maple ( 170 ) Limited | Administrative & support | 2002 |
| Maple Developments Limited | Administrative & support | 1999 |
| Maple Leaf Holdings Ltd | Professional & scientific | 2020 |
| Mapleson Ltd | Professional & scientific | 2015 |
| Maramu Developments Ltd | Extraterritorial | 2019 |
| Marble Websites Limited | Information & communication | 2022 |
| Marbury Consulting Limited | Professional & scientific | 2014 |
| Marbury Hall Nurseries Ltd | Wholesale & retail | 2022 |
| Marbury Limited | Construction | 2019 |
| Marial Gwyn Limited | Agriculture & fishing | 2022 |
| Mark Herron Consulting Ltd | Professional & scientific | 2011 |
| Mark Holman Lighting Ltd | Wholesale & retail | 2018 |
| Mark P. Barlow (Northwich) Limited | Transport & logistics | 2010 |
| Mark Roberts Logistics Limited | Administrative & support | 2023 |
| Mark Woods Limited | Administrative & support | 2008 |
| Mark Woodward First Steps Limited | Professional & scientific | 2018 |
| Market Technology Ltd | Financial services | 2025 |
| Markmaster Ltd | Information & communication | 2026 |
| Markone Polymers Ltd | Manufacturing | 2009 |
| Marmaris Kebab and Pizza Ltd | Hospitality | 2026 |
| Mars Property & Homes Ltd | Real estate | 2024 |
| Marsh Box Developments Limited | Construction | 2017 |
| Martin Bates Consultancy Limited | Professional & scientific | 2009 |
| Martin Brown Golf Ltd | Arts & recreation | 2015 |
| Martin M Multiservice Ltd | Wholesale & retail | 2014 |
| Martins Fields Residents Association Limited | Households | 2008 |
| Mary Puppins Pet Care Limited | Other services | 2021 |
| Marzolo Inspection Limited | Professional & scientific | 2010 |
| MAS Construction (NW) Limited | Construction | 2009 |
| MAS Endeavours Limited | Administrative & support | 2021 |
| MAS Endeavours Property Limited | Real estate | 2023 |
| Materialsinformation Ltd | Information & communication | 2024 |
| Maternity Funding Group Limited Partnership | | 2019 |
| Matt Godwin Electrical Ltd | Construction | 2006 |
| Matt Tidmarsh Editor Limited | Information & communication | 2014 |
| Matthew Gregory King Limited | Agriculture & fishing | 2004 |
| Matthew Walton (Holdings) Limited | Professional & scientific | 2016 |
| Matthew Walton Limited | Information & communication | 2012 |
| Matthews&Co Limited | Professional & scientific | 2010 |
| Maxim M&G Ltd | Hospitality | 2020 |
| Maxwell Property Lettings Ltd | Real estate | 2024 |
| Maxyco Ltd | Professional & scientific | 2018 |
| MAY Fradley Limited | Financial services | 2018 |
| Mayberry Property Developments Ltd | Construction | 2026 |
| Mayfarm Capital Limited | Real estate | 2013 |
| Mayflower Bloom Limited | Wholesale & retail | 2013 |
| Mayflower Brides Limited | Wholesale & retail | 2021 |
| Mayhew Consulting Limited | Information & communication | 2014 |
| Maynards Stock Auditors Ltd | Other services | 2017 |
| Mayorling Limited | Real estate | 2004 |