| Medispray Technologies Limited | Professional & scientific | 2021 |
| Medx Pharmaceuticals Ltd | Manufacturing | 2023 |
| Mekong & Mersey Enterprises Ltd | Real estate | 2025 |
| Melia Civil Engineering Limited | Construction | 2013 |
| Meliabirchall Ltd | Real estate | 2021 |
| Mell Wood Residents Association RTM Company Limited | Administrative & support | 2005 |
| Mellow Sedation Limited | Health & social care | 2017 |
| Melts Ormskirk Limited | Hospitality | 2019 |
| Membrane Tech Services Limited | Construction | 2026 |
| Menard Limited | Construction | 1992 |
| Menergise Ltd | Health & social care | 2024 |
| MEP Electrical Ltd | Construction | 2008 |
| Mereside Toxicology Consulting Limited | Professional & scientific | 2015 |
| Merewood Holdings Limited | Financial services | 2019 |
| Mero Investment Ltd | Real estate | 2025 |
| Merry Hell Limited | Arts & recreation | 2026 |
| Mersey Heat Pumps Ltd | Construction | 2024 |
| Mersey Wind Renewables Ltd | Manufacturing | 2026 |
| Merseyboilers Ltd | Construction | 2023 |
| Merseyside Trading Limited | Wholesale & retail | 2022 |
| Metech ICT Ltd | Manufacturing | 2018 |
| Metro & Metro UK Limited | Wholesale & retail | 2008 |
| MEW and Friends Limited | Wholesale & retail | 2022 |
| Mez-Tap Ltd | Hospitality | 2017 |
| Mglh Limited | Transport & logistics | 2016 |
| Mhdp Limited | Health & social care | 2014 |
| MHW 60 Ltd | Professional & scientific | 2010 |
| MI Couriers Limited | Wholesale & retail | 2017 |
| Mi-Heat UK Ltd | Wholesale & retail | 2020 |
| Michael Mcdonald Electrical Contracting Limited | Construction | 2014 |
| Michael Pearce Limited | Wholesale & retail | 2001 |
| Michelle Oakes Ltd | Education | 2022 |
| Middle Child Communications Ltd | Professional & scientific | 2019 |
| Middleton Medical HR Solutions Ltd | Administrative & support | 2025 |
| Mike Davies IFA Limited | Professional & scientific | 2021 |
| Mike Gall Mortgage Services Ltd | Financial services | 2023 |
| Mike Hurst Scenic Carpentry Ltd | Manufacturing | 2021 |
| Mike O'Neill Financial Services Limited | Professional & scientific | 2020 |
| Mill View Doggy Retreat Ltd | Other services | 2025 |
| Milli-Mae Fitness Ltd | Arts & recreation | 2025 |
| Millmax Training Ltd | Education | 2025 |
| Mindspace Services Limited | Health & social care | 2017 |
| Mineral Minds Ltd | Wholesale & retail | 2024 |
| Mirage Enterprises Ltd | Professional & scientific | 2009 |
| MJ & PJ Properties Ltd | Real estate | 2025 |
| MJ Building Plastics Limited | Wholesale & retail | 2013 |
| MJC Contractors (NW) Ltd | Administrative & support | 2026 |
| MJE Travel Limited | Transport & logistics | 2017 |
| MJF Works Ltd | Construction | 2026 |
| MJK Knowles Limited | Financial services | 2025 |
| MJL Estates Ltd | Real estate | 2017 |
| MJS Holdings Group Limited | Professional & scientific | 2024 |
| MKC Plumbing & Heating Ltd | Energy | 2024 |
| MLH Projects Ltd | Arts & recreation | 2025 |
| MLS Independent Funeral Directors Limited | Other services | 2014 |
| MLW Consultancy Ltd | Wholesale & retail | 2022 |
| MM Consultancy NW Ltd | Extraterritorial | 2019 |
| MM Services 16 Ltd | Other services | 2016 |
| MM Solutions Burscough Limited | Administrative & support | 2025 |
| Mmcr Ltd | Professional & scientific | 2021 |
| MMJ Joinery Limited | Construction | 2005 |
| MNG Commercials Limited | Manufacturing | 2010 |
| Mobile Living Limited | Other services | 2025 |
| Modern Mist Ltd | Wholesale & retail | 2023 |
| Mollard Developments Ltd | Real estate | 2020 |
| MOMENTUM-DIVING4FUN Ltd | Arts & recreation | 2015 |
| MON Petit Ltd | Real estate | 2020 |
| Montacle Ltd | Information & communication | 2026 |
| Montica Limited | Professional & scientific | 2024 |
| Moor Hall Holdings Limited | Other services | 2014 |
| Moor Hall Limited | Real estate | 2014 |
| Moor Hall Restaurant Limited | Hospitality | 2014 |
| Moreish Catering Ltd | Hospitality | 2021 |
| Morestore NW Ltd | Transport & logistics | 2023 |
| Morris Developments NW Limited | Real estate | 2025 |
| Moss Cottage Limited | Wholesale & retail | 2009 |
| Moss Nook Honey Ltd | Agriculture & fishing | 2023 |
| Moss Nook Management Limited | Real estate | 2015 |
| Motto Studio Limited | Professional & scientific | 2021 |
| Mount Carmel Gardens Management Company Ltd | Households | 2016 |
| Mountain ASH Investments Limited | Professional & scientific | 1994 |
| Mountain Joe's Limited | Hospitality | 2017 |
| Movesafe Systems Ltd | Information & communication | 2026 |
| Moving Style Limited | Real estate | 2007 |
| MOX Limited | Wholesale & retail | 2012 |
| MOY Developments Limited | Real estate | 2003 |
| MP Electrics (Liverpool) Limited | Construction | 2016 |
| MPB Contracts Ltd | Agriculture & fishing | 2015 |
| MR Certification Limited | Professional & scientific | 2023 |
| MRF Engineering Services Limited | Construction | 2015 |
| MRS Glam Ltd | Real estate | 2021 |
| MSC Prestige Garage Ltd | Wholesale & retail | 2011 |
| Mserv Limited | Construction | 2010 |
| Mserv Modular Ltd | Professional & scientific | 2016 |
| MTB (Midlands) Limited | Water & waste | 1998 |
| MTC Engineering Systems Ltd | Manufacturing | 2014 |
| Multiform Developments Limited | Extraterritorial | 2013 |
| Multiform Projects Holdings Limited | Financial services | 2013 |
| MUM Stamped Ltd | Information & communication | 2025 |
| Munchkins Village Nursery Limited | Health & social care | 2012 |