| Mersanto | Professional & scientific | 2026 |
| Mersey-Douglas Property Group Ltd | Real estate | 2026 |
| Merseyside Logistics Limited | Transport & logistics | 2007 |
| Mervat Properties Ltd | Real estate | 2025 |
| MES (NW) Limited | Professional & scientific | 2011 |
| MES Food Group Limited | Hospitality | 2025 |
| Mesnes Street Carpet Centre Limited | Wholesale & retail | 1980 |
| Mesnes Street Collective CIC | Education | 2026 |
| Metacad Engineering Solutions Ltd | Professional & scientific | 2010 |
| Metaija | Professional & scientific | 2023 |
| Metaltech (Bolton) Limited | Manufacturing | 2009 |
| Metaltech North West Limited | Manufacturing | 2019 |
| Metamic Engineering Ltd | Professional & scientific | 2020 |
| Metaza Ltd | Information & communication | 2022 |
| Method Asset Management Limited | Financial services | 2020 |
| Methodical Design Ltd | Professional & scientific | 2024 |
| MF Electrical Services Ltd | Construction | 2021 |
| MF Medical Services Ltd | Health & social care | 2024 |
| MG Plumbing and Heating Solutions Ltd | Construction | 2025 |
| MG Property Projects Ltd | Real estate | 2025 |
| MG77 Productions Ltd | Professional & scientific | 2021 |
| Mgas Plumbing & Heating Ltd | Construction | 2020 |
| MGB Scaffolding Limited | Construction | 2015 |
| MGK Properties Limited | Real estate | 2024 |
| Mguk (F&C) Limited | Real estate | 2019 |
| Mguk Sales & Lettings Limited | Real estate | 2019 |
| MGW (NW) Limited | Professional & scientific | 2017 |
| Mgway Ltd | Transport & logistics | 2014 |
| MH Building Services NW Limited | Construction | 2023 |
| MH Partitions & Interiors Limited | Construction | 2017 |
| MHW Contracts NW Ltd | Wholesale & retail | 2017 |
| MI Houses and Properties Limited | Households | 2026 |
| MIA Nails Beauty Ltd | Other services | 2023 |
| Miami Pizza Limited | Hospitality | 2022 |
| Mian & Moiz Co Ltd | Wholesale & retail | 2025 |
| Mibi Holdings & Co Ltd | Transport & logistics | 2022 |
| Michael a. Welch (Consulting Engineers) Limited | Professional & scientific | 1985 |
| Michael Almond Joinery & Building Services Ltd | Construction | 2015 |
| Michael Evans (2015) Limited | Transport & logistics | 2015 |
| Michael Green Television Limited | Information & communication | 2012 |
| Michael Kisluk Limited | Transport & logistics | 2002 |
| Michaelalan Ltd | Financial services | 2013 |
| Mick Lynch Limited | Construction | 2015 |
| Micro Infotech Limited | Professional & scientific | 2015 |
| Micro Media Consultants Ltd | Professional & scientific | 2026 |
| Microface Limited | Information & communication | 1981 |
| Midas Shine Limited | Wholesale & retail | 2025 |
| Middlehurst Ltd | Education | 2017 |
| Middleton Developments Ltd | Real estate | 2023 |
| Midget Properties Limited | Real estate | 2024 |
| MIG HR Solutions Ltd. | Administrative & support | 2025 |
| Migolis Ltd | Professional & scientific | 2026 |
| Mihaikrm Ltd | Transport & logistics | 2025 |
| MII Houses Limited | Households | 2026 |
| MII Properties Ltd | Households | 2026 |
| Miit Consulting Ltd | Professional & scientific | 2024 |
| Mikaluca | Professional & scientific | 2023 |
| Mikatsy Limited | Manufacturing | 2015 |
| Mike Grundy MMA Ltd | Arts & recreation | 2025 |
| Milack Logistics Ltd | Transport & logistics | 2015 |
| Milarepic | Professional & scientific | 2023 |
| Milatrex | Professional & scientific | 2025 |
| Milepost Coffee Ltd | Hospitality | 2026 |
| Mill Brook View Ltd | Construction | 2022 |
| Mill Leat Management Company (Parbold) Limited | Households | 1988 |
| Millan Interiors Ltd | Wholesale & retail | 2026 |
| Millbank Apartments (Management) Limited | Real estate | 2005 |
| Millcroft Design Services (MDS) Ltd | Professional & scientific | 2020 |
| Miller & Monks Holdings Ltd | Real estate | 2025 |
| Milliken Industrials Limited | Manufacturing | 1920 |
| Millscapes NW Ltd | Administrative & support | 2025 |
| Millstone Inn (Wigan Lane) Limited | Hospitality | 2008 |
| Minbica Ltd | Wholesale & retail | 2021 |
| Mind Body Health Wellbeing CIC | Health & social care | 2023 |
| Mind Train CIC | Education | 2018 |
| Mindbody Harmony Ltd | Professional & scientific | 2024 |
| Mindful by Nature Ltd | Administrative & support | 2022 |
| Mindmal Ltd | Financial services | 2023 |
| Mindmosh Limited | Information & communication | 2013 |
| Mindset Association CIC | Education | 2026 |
| Mineserve Global Limited | Mining & quarrying | 2025 |
| Ming Garden Wigan Limited | Hospitality | 2026 |
| Minimal Mind Ltd | Information & communication | 2024 |
| Minimiser Limited | Professional & scientific | 2008 |
| Mint Hotels Limited | Hospitality | 1987 |
| Mint Joinery & Building Ltd | Extraterritorial | 2010 |
| Mint Northwest Ltd | Construction | 1997 |
| Minterior Limited | Manufacturing | 2018 |
| Mira Maintenance and Renovation Limited | Construction | 2024 |
| Miratogu Ltd | Professional & scientific | 2026 |
| Mirror & Mane Ltd | Other services | 2024 |
| Miry Lane Breakers Limited | Wholesale & retail | 2024 |
| Mirzagi OFF License Ltd | Wholesale & retail | 2019 |
| Mison Consulting Ltd | Information & communication | 2019 |
| Miss Katie’S Dance Limited | Education | 2018 |
| Missing Link Communications Limited | Information & communication | 1997 |
| Mission Care Associate Ltd | Health & social care | 2024 |
| Mission Fitness (Bury) Limited | Arts & recreation | 2024 |
| Mission Inspire Limited | Arts & recreation | 2021 |
| Misson Estates Limited | Administrative & support | 2001 |