| Meadowbrook Rise Management Company Limited | Real estate | 2018 |
| Meadowhead Homes Limited | Real estate | 2025 |
| Meadows Decorators Ltd | Construction | 2024 |
| Meadowview Property Management Ltd | Real estate | 2020 |
| Meaningful Care Solutions Ltd | Health & social care | 2025 |
| Mediathing Limited | Arts & recreation | 2021 |
| Mediverse Medical Services Limited | Health & social care | 2025 |
| Mega Crunch Cafe Ltd | Hospitality | 2025 |
| Meid Sharm Limited | Manufacturing | 2025 |
| Melbro Group Ltd | Real estate | 1982 |
| Melia Holdings Ltd | Extraterritorial | 2018 |
| Melia Law Ltd | Professional & scientific | 2023 |
| Melia Trading Co Ltd | Real estate | 2003 |
| Melina Joy Opticians Limited | Wholesale & retail | 2000 |
| Melody Makers Piano Ltd | Education | 2025 |
| Melting POT Promotions Ltd | Wholesale & retail | 2015 |
| Memory Opticians Limited | Wholesale & retail | 2002 |
| Men's Barber (Darwen) Ltd | Other services | 2023 |
| Mercantile Commercial Services Ltd | Manufacturing | 2019 |
| Merch Network Limited | Manufacturing | 2019 |
| Merchant Intelligence Bureau Ltd | Professional & scientific | 2023 |
| Merlin Eyecare Limited | Health & social care | 2005 |
| Merseyside Stove Installers Limited | Construction | 2021 |
| Metcoat Ltd | Manufacturing | 2011 |
| Metglass Ltd | Construction | 2017 |
| Metropia Optics Ltd | Wholesale & retail | 2013 |
| Mettlers Ltd | Wholesale & retail | 2024 |
| Mfsy EYE Specialist Ltd | Health & social care | 2022 |
| MG Digital Media Ltd | Information & communication | 2020 |
| Mgim Optical Limited | Wholesale & retail | 2016 |
| MHM Equine Dentistry Limited | Professional & scientific | 2015 |
| Micro Merger UK Ltd | Information & communication | 2022 |
| Middle Mouse Group Limited | Information & communication | 2018 |
| Mijo Holdings Ltd | Wholesale & retail | 2024 |
| Milecharm Ltd | Professional & scientific | 1995 |
| Milk Bread and Ingredients Ltd | Hospitality | 2016 |
| Mill Hill Taverns Ltd | Hospitality | 2019 |
| Millbank Legal & Financial Ltd | Administrative & support | 2016 |
| Mind Media Limited | Information & communication | 2023 |
| Minerva Fabrics Limited | Wholesale & retail | 2003 |
| Minsa Collection Limited | Wholesale & retail | 2025 |
| Mint Seating Limited | Manufacturing | 2019 |
| Miss Nails Studio Limited | Other services | 2018 |
| MJ CNC Services Limited | Professional & scientific | 2026 |
| MJA Ltd | Professional & scientific | 2026 |
| MKO (S5) Ltd | Wholesale & retail | 2016 |
| MKS Roofing & Cladding Limited | Construction | 2009 |
| MKW Acquisitions Ltd | Households | 2025 |
| MKW Finance Solutions Ltd | Financial services | 2025 |
| MKW Global Holdings Ltd | Financial services | 2025 |
| MLE Asset Limited | Administrative & support | 2015 |
| MOD EYE Limited | Health & social care | 2000 |
| Moda Active Ltd | Wholesale & retail | 2022 |
| Modesttrendz Limited | Wholesale & retail | 2023 |
| Mollydoo Baby Ltd | Manufacturing | 2018 |
| Monnow Eyecare Limited | Health & social care | 2007 |
| Monpeak Limited | Wholesale & retail | 2026 |
| Montyjamesbars Ltd | Hospitality | 2024 |
| Moorland Homes Ltd | Construction | 2019 |
| Moorland Homes Properties Ltd | Real estate | 2025 |
| Moorview Estates Limited | Real estate | 2021 |
| Moorview Livery Ltd | Real estate | 2021 |
| Moorview Saddlery Limited | Wholesale & retail | 2002 |
| Morgan Haynes Limited | Professional & scientific | 2008 |
| Morgan Jake Ltd | Information & communication | 2025 |
| Morganpeter Ltd | Manufacturing | 2019 |
| Moss Fold Properties Limited | Real estate | 1995 |
| Moss Hill Mushrooms Ltd | Agriculture & fishing | 2023 |
| Moss Investments (N/W) Ltd | Real estate | 2007 |
| Mosspro Properties Ltd | Real estate | 2019 |
| Motor Robs Garage Ltd | Wholesale & retail | 2021 |
| Motorlodge Limited | Transport & logistics | 2025 |
| Motornuts Limited | Wholesale & retail | 2016 |
| Moulton Property Management Ltd | Real estate | 2025 |
| Moxzie Ltd | Wholesale & retail | 2024 |
| Mpharm Ltd | Health & social care | 2009 |
| MPW Technology Group Limited | Real estate | 2019 |
| Mropticaluk Ltd | Manufacturing | 2019 |
| MS Contractors Building Services Limited | Construction | 2023 |
| MS GAS Services Ltd | Construction | 2021 |
| MSD Hearing Limited | Wholesale & retail | 2021 |
| MTL Advanced Ltd | Manufacturing | 2011 |
| Mughal NWS Ltd | Hospitality | 2025 |
| Mulcahy Electrical Ltd | Construction | 2017 |
| Multevo Group Limited | Extraterritorial | 2011 |
| Multevo Limited | Wholesale & retail | 2010 |
| Murmac Holdings Limited | Real estate | 2014 |
| MW Collectables Ltd | Other services | 2020 |
| My Claims Handler Limited | Financial services | 2022 |
| My Island Home Limited | Wholesale & retail | 2019 |
| My Optician Limited | Health & social care | 2011 |
| Myers Creative Ltd | Professional & scientific | 2019 |
| MYL Foods Limited | Hospitality | 2024 |
| MZH Properties Limited | Real estate | 2026 |
| N & a Plant Hire Limited | Administrative & support | 2015 |
| N W Motors (Darwen) Ltd | Wholesale & retail | 2026 |
| N. & J. Robinson Optometrists Limited | Wholesale & retail | 2002 |
| Nags Head PUB Co Limited | Hospitality | 2022 |
| Nain Trades Limited | Wholesale & retail | 2025 |
| Narrew Ltd | Wholesale & retail | 2020 |