| M & L C Properties Limited | Real estate | 2024 |
| M & M Ashton Limited | Wholesale & retail | 2005 |
| M & M Windows Ltd | Manufacturing | 2005 |
| M & N Plastering Limited | Construction | 2014 |
| M & R GAS Services Limited | Construction | 2006 |
| M & R Property and Holdings Ltd | Real estate | 2018 |
| M & S Healthcare Services Limited | Health & social care | 2016 |
| M & W Autobodies Limited | Wholesale & retail | 2007 |
| M &L Jones Ltd | Construction | 2020 |
| M a Contracting Services Limited | Construction | 2014 |
| M a Richardson Limited | Professional & scientific | 2019 |
| M and H Construction and Utilities Limited | Construction | 2011 |
| M and S Property Renovations Ltd | Construction | 2026 |
| M Ashton NW Ltd | Hospitality | 2025 |
| M B Heating (Holdings) Limited | Professional & scientific | 2006 |
| M B Soils & Groundworks Ltd | Construction | 2013 |
| M C Jones Limited | Hospitality | 2015 |
| M Capelli Ltd | Other services | 2016 |
| M D W Couriers Ltd | Transport & logistics | 2025 |
| M Davies & Sons Ltd | Hospitality | 2025 |
| M Feeney Brickwork Ltd | Construction | 2013 |
| M I T Solutions Limited | Wholesale & retail | 2008 |
| M J Miller & Co Limited | Professional & scientific | 2007 |
| M J R Travel Ltd | Transport & logistics | 2020 |
| M J Wilson Electrical Services Ltd | Construction | 2014 |
| M K Transportation Ltd | Transport & logistics | 2018 |
| M L Auto Repairs Limited | Wholesale & retail | 2009 |
| M M Construction Group Limited | Construction | 2021 |
| M M Electrical Contractors Limited | Construction | 2014 |
| M Monaghan's Property Limited | Extraterritorial | 2020 |
| M P & K Limited | Construction | 2024 |
| M Parr Ltd | Real estate | 2025 |
| M R L Ceilings @ Partitions Ltd | Construction | 2025 |
| M&A Expert Limited | Wholesale & retail | 2024 |
| M&A Living Ltd | Health & social care | 2025 |
| M&C Restaurants (NW) Ltd | Hospitality | 2019 |
| M&G Auto's Wigan Ltd | Wholesale & retail | 2025 |
| M&H (2023) Limited | Other services | 2023 |
| M&J Wood Consulting Limited | Professional & scientific | 2025 |
| M&K Commercial Repairs Ltd | Wholesale & retail | 2024 |
| M&K Projects Ltd | Construction | 2017 |
| M&K Residences Ltd | Real estate | 2024 |
| M&L Wigan Valeting Centre Ltd | Other services | 2021 |
| M&M (MAN) Ltd | Hospitality | 2025 |
| M&M Accounting & Payroll Services Ltd | Professional & scientific | 2023 |
| M&M Aluminium Windows & Doors Ltd | Manufacturing | 2025 |
| M&M Future Solutions Limited | Other services | 2017 |
| M&M Prop SOL Limited | Manufacturing | 2025 |
| M&M Properties Wigan Ltd | Real estate | 2021 |
| M&N Builders Limited | Construction | 2024 |
| M&N Heating & GAS Limited | Manufacturing | 2018 |
| M&O IR Limited | Arts & recreation | 2024 |
| M&T Ceilings & Partitions Ltd | Construction | 2017 |
| M-Phd Ltd | Construction | 2016 |
| M. B. Heating Limited | Construction | 2001 |
| M.A.C. Housing Limited | Real estate | 1999 |
| M.A.P Road Transport Ltd | Transport & logistics | 2026 |
| M.D.A. Installations (N.W.) Limited | Wholesale & retail | 2011 |
| M.R.A.J. Properties Ltd | Real estate | 2021 |
| M.Rutter Plumbing and Heating Ltd | Construction | 2019 |
| M.W. Kelly Haulage Limited | Transport & logistics | 2002 |
| M6 Motor Service Limited | Manufacturing | 2011 |
| M6 North West Breakdown Recovery Rescue Limited | Wholesale & retail | 2025 |
| Ma-Anaesthesia Ltd | Health & social care | 2023 |
| MAC Groundwork’S and Construction Ltd | Construction | 2020 |
| MAC Mobile Mechanics Ltd | Wholesale & retail | 2019 |
| MAC Property (North West) Limited | Real estate | 2025 |
| MAC Psychology Ltd | Education | 2020 |
| MAC Transformations Ltd | Construction | 2024 |
| Macalus | Professional & scientific | 2025 |
| Macdermid Canning Limited | Manufacturing | 1955 |
| Macemot | Professional & scientific | 2026 |
| Machine Rendering Northwest Limited | Construction | 2019 |
| Machine Vision Intelligence Ltd | Information & communication | 2024 |
| Mack Mcgoldrick Haulage & Plant Hire Limited | Transport & logistics | 2012 |
| Macleary Ltd | Professional & scientific | 2018 |
| Macro Networks Ltd | Manufacturing | 2017 |
| Macross Estates Limited | Households | 2025 |
| Macsure Support Ltd | Health & social care | 2025 |
| MAD 4 I.T Limited | Information & communication | 2004 |
| Madani Holdings Limited | Financial services | 2024 |
| Madath Ltd | Professional & scientific | 2024 |
| Maddox Holdings Limited | Arts & recreation | 2019 |
| Made for the JOB Ltd | Construction | 2024 |
| Made Profiles Limited | Manufacturing | 2013 |
| Made to Make Limited | Manufacturing | 2025 |
| Madell Commercial Limited | Real estate | 2025 |
| Madell Group Limited | Financial services | 2024 |
| Madell Management Limited | Households | 2023 |
| Madell Properties Limited | Real estate | 2024 |
| Madora Property Management Limited | Real estate | 2018 |
| MAF Reporting Limited | Professional & scientific | 2018 |
| Mafia Boss Studios Ltd | Arts & recreation | 2025 |
| Mafitconsulting Limited | Information & communication | 2007 |
| Magic Books Online Limited | Wholesale & retail | 2011 |
| Magic Scissor PVT Limited | Other services | 2025 |
| Magicalbliss Ltd | Manufacturing | 2025 |
| Magicalogical Limited | Administrative & support | 2017 |
| Magil Group Ltd | Professional & scientific | 2022 |
| Magnifyhr Ltd | Administrative & support | 2025 |