| Mount Group Services Ltd | Agriculture & fishing | 2023 |
| Mountfield Court Residents Association RTM Company Ltd | Households | 2010 |
| Movaro Logistics Ltd | Transport & logistics | 2025 |
| Moxham Consulting Ltd | Professional & scientific | 2021 |
| Moxie Ventures Ltd | Real estate | 2025 |
| Moyles Carpets and Flooring Limited | Construction | 2020 |
| MP Outdoor Creations Limited | Administrative & support | 2023 |
| MPF Coded Welding Services Limited | Construction | 2015 |
| MPF Energy Solutions Limited | Professional & scientific | 2015 |
| MPM UK Wholesale Ltd | Wholesale & retail | 2023 |
| Mpulse Limited | Professional & scientific | 1995 |
| MQS Healthcare Ltd | Health & social care | 2025 |
| MR Access Nationwide Limited | Construction | 2019 |
| MR Codz Chippy Ltd | Hospitality | 2025 |
| MR LAM Enterprise Ltd | Real estate | 2019 |
| MR Mac's Stadium Chippy Ltd | Hospitality | 2021 |
| MR Macs English Fish & Chips Ltd | Hospitality | 2014 |
| MR Pizza Bury Ltd | Hospitality | 2025 |
| MR Prestige UK Limited | Wholesale & retail | 2026 |
| MR Smart Ltd | Wholesale & retail | 2003 |
| MR. Constantine Hair Design Ltd | Other services | 1987 |
| Mreps Trustees (NO 80) Limited | Professional & scientific | 2003 |
| MRJ Vision Limited | Health & social care | 2016 |
| Mrjr Ltd | Construction | 2019 |
| MS Food Solutions Ltd | Wholesale & retail | 2014 |
| MS Operations Ltd | Professional & scientific | 2026 |
| MS Overcomer C.I.C. | Health & social care | 2020 |
| MS Retailers Ltd | Wholesale & retail | 2016 |
| MS1 Wholesale Limited | Wholesale & retail | 2023 |
| MS2 Energy Limited | Professional & scientific | 2010 |
| Msakm Ltd | Real estate | 2025 |
| MSC Marketing &Consulting Ltd | Information & communication | 2016 |
| Mseot Limited | Professional & scientific | 2019 |
| MSH Installations Limited | Construction | 2024 |
| MSK1 Consulting Ltd | Professional & scientific | 2016 |
| Mslg Vehicle Body Repairs Ltd | Wholesale & retail | 2026 |
| Msmj Group Holdings Limited | Financial services | 2025 |
| Mspb Services Limited | Real estate | 2023 |
| MSR Corporate Ltd | Financial services | 2015 |
| MT Automotive Consultancy Limited | Professional & scientific | 2026 |
| MT Bunkring LP Ltd | Other services | 2025 |
| MT Retail (Bury) Ltd | Wholesale & retail | 2025 |
| MT Retail (Lancaster) Ltd | Wholesale & retail | 2024 |
| MT Retail UK Ltd | Wholesale & retail | 2021 |
| MT Retail UK MOT Ltd | Wholesale & retail | 2026 |
| Mtec Industrial Power Washing Ltd | Professional & scientific | 2015 |
| MTR Leisure Ltd | Arts & recreation | 2025 |
| MTZ Consultants Limited | Information & communication | 2010 |
| MUA Group Ltd | Financial services | 2025 |
| Muaa Ltd | Wholesale & retail | 2026 |
| Muay Thai Shop UK Limited | Wholesale & retail | 2024 |
| Muazzam Chauffeur Service Ltd | Wholesale & retail | 2024 |
| Muck & Stuff Ltd | Construction | 2001 |
| Muckdog Ltd | Manufacturing | 2026 |
| Mucker Clothing Ltd | Wholesale & retail | 2025 |
| Muddy Mochas Ltd | Hospitality | 2024 |
| Mukhtar Property Legal Services Ltd | Professional & scientific | 2025 |
| Mulberry Bush Nursery Group Limited | Professional & scientific | 2010 |
| Mulberry Bush Nursery Limited | Administrative & support | 2000 |
| Mulberry Lettings & Developments Limited | Real estate | 2018 |
| Mulberry Tree Management Consultancy Limited | Agriculture & fishing | 2008 |
| Mulman Ltd | Wholesale & retail | 2021 |
| Multi-Trading Ltd | Wholesale & retail | 2026 |
| Multiscaff Ltd | Construction | 1994 |
| Mumedia Limited | Professional & scientific | 2025 |
| Munchies Bury Ltd | Hospitality | 2025 |
| Munchies House Ltd | Hospitality | 2019 |
| Mundays Property Solutions Ltd | Households | 2023 |
| Munib Essa T/A Roccos Desserts Ltd | Hospitality | 2020 |
| Munro-Greenhalgh Holdings Limited | Financial services | 2016 |
| Muqaddas PVT Limited | Wholesale & retail | 2025 |
| Mura Trading Limited | Hospitality | 2017 |
| Murphy Midland Group Limited | Construction | 2016 |
| Murphy Pm&I Ltd | Real estate | 2021 |
| Murrays Limited | Wholesale & retail | 2000 |
| Murton Pizza and Kebab Ltd | Hospitality | 2019 |
| Musa Spark Ltd | Administrative & support | 2024 |
| Museum and Gallery Lighting Limited | Manufacturing | 1992 |
| Mushtaq Innovations Ltd | Wholesale & retail | 2024 |
| Mussa Fast Food Ltd | Hospitality | 2025 |
| Muzzpharma Ltd | Health & social care | 2023 |
| Mvmnt Supplements Ltd | Wholesale & retail | 2025 |
| MVP Realisations Limited | | 1999 |
| MW (UK) Technology Logistics Inc Limited | Administrative & support | 2025 |
| MW Fulfilment Services Ltd | Administrative & support | 2018 |
| MW Northwest Ltd | Administrative & support | 2022 |
| MWH Holdings Ltd | Professional & scientific | 2026 |
| My Choice Cloud Limited | Wholesale & retail | 2025 |
| My Eco Home Limited | Construction | 2022 |
| My House Clearance Ltd | Transport & logistics | 2020 |
| My Little Legs CIC | Education | 2025 |
| My MAN and Van Ltd | Construction | 2019 |
| My Own Muse Communications Ltd | Professional & scientific | 2018 |
| My Plaice (Edenfield) Limited | Hospitality | 2023 |
| My Scene Ltd | Professional & scientific | 2020 |
| My Skin Health Ltd | Health & social care | 2026 |
| My Time Wellness Ltd | Health & social care | 2019 |
| My Transfer Airport Ltd | Transport & logistics | 2023 |
| Mycc Developments Limited | Real estate | 2021 |
| MYI45 Ltd | Wholesale & retail | 2026 |