| Midtown Investments Limited | Financial services | 1999 |
| Midway Chauffeur Services Limited | Other services | 1998 |
| Mihai Building Services Ltd | Construction | 2017 |
| Mihika Impex Limited | Professional & scientific | 1999 |
| Mike Wright Network Support Services Limited | Information & communication | 2001 |
| Miles Property Services Limited | Real estate | 2006 |
| Milky Films Limited | Information & communication | 2007 |
| Mill Court (Residents Association) Limited | Households | 1974 |
| Millar Associates Limited | Professional & scientific | 2001 |
| Millenia Limited | Health & social care | 1992 |
| Millwright Limited | Construction | 1996 |
| Millwright's Plumbing & Electrical Ltd | Wholesale & retail | 2006 |
| Mindale Limited | Administrative & support | 2006 |
| Minehead Court Limited | Real estate | 1996 |
| Minhas Motors Limited | Manufacturing | 1999 |
| Mini-Hab Ltd | Real estate | 2004 |
| Minicraft Textiles Limited | Transport & logistics | 1985 |
| Minim Technology Limited | Wholesale & retail | 1997 |
| Miniview Properties Limited | Real estate | 1999 |
| Minmar (291) Limited | Administrative & support | 1995 |
| Minstrel Properties Limited | Real estate | 2024 |
| Mintax Limited | Professional & scientific | 2003 |
| Mira Manek Limited | Other services | 2024 |
| Miraflores Bar and Lounge Limited | Hospitality | 2018 |
| Mirc Company Limited | Information & communication | 1995 |
| Mirinda Limited | Hospitality | 1996 |
| Miss Ltd | Professional & scientific | 2005 |
| Mistry Estates Ltd | Real estate | 2005 |
| Mitchells PHV Chauffeur Ltd | Transport & logistics | 2023 |
| Mitocon UK Ltd | Professional & scientific | 2024 |
| Mixed Network Systems Limited | Information & communication | 1997 |
| Mixwane Limited | Information & communication | 1998 |
| Mixward Limited | Real estate | 1995 |
| MJ Global Trading Co. Ltd | Wholesale & retail | 2019 |
| MJ Webb Maintenance & Alterations Ltd | Construction | 2025 |
| MJF Property Administration Limited | Real estate | 2021 |
| MJF Surveying Consultants Limited | Administrative & support | 2007 |
| MJN Creative Solutions Ltd | Arts & recreation | 2015 |
| Mjna Ltd | Real estate | 1999 |
| MK Filling Station Ltd | Wholesale & retail | 2022 |
| MK Ventures Ltd | Hospitality | 2022 |
| MLA Solutions Limited | Professional & scientific | 1999 |
| MMN Estate Ltd | Real estate | 2020 |
| MMS Consultancy Limited | Professional & scientific | 2001 |
| MND Construction Services Limited | Other services | 2007 |
| MNR Limited | Professional & scientific | 2002 |
| MNS Services Limited | Professional & scientific | 1994 |
| MNX Global Logistics Limited | Transport & logistics | 1984 |
| Mobella Limited | Professional & scientific | 2007 |
| Mobile Phone Recycling Limited | Professional & scientific | 2006 |
| Modak Property Investments Limited | Real estate | 2024 |
| Mohabbatein Dance Academy | Arts & recreation | 2001 |
| Mohipop Limited | Professional & scientific | 2008 |
| Mohsinravjaniconsultancy Limited | Professional & scientific | 2025 |
| Molesley Limited | Wholesale & retail | 1991 |
| Molly Sole Limited | Information & communication | 2014 |
| Momi Homes Constructions Ltd | Construction | 2025 |
| Momoste Limited | Hospitality | 2025 |
| Mona Offshore Wind Holdings Limited | Financial services | 2021 |
| Mona Offshore Wind Limited | Construction | 2021 |
| Monaf's Restaurant Limited | Hospitality | 2021 |
| Monarock Limited | Real estate | 2001 |
| Money Compass Limited | Financial services | 2008 |
| Moneywise Direct Ltd | Information & communication | 2004 |
| Monkey in Heaven Films Limited | Extraterritorial | 1999 |
| Monkeybread Limited | Information & communication | 2005 |
| Monohill Limited | Other services | 1986 |
| Monterey Freehold Limited | Real estate | 2004 |
| Moony Europe Limited | Wholesale & retail | 2006 |
| Moor Park (1958) Limited | Households | 1958 |
| Moor Road Property Management Limited | Households | 2004 |
| More-Fx Ltd | Arts & recreation | 2016 |
| Morelli & Co.(London)Limited | Wholesale & retail | 1957 |
| Morelli Group Limited | Wholesale & retail | 1992 |
| Morgan Berkeley (South East) Limited | Extraterritorial | 2000 |
| Morgan Freelance Limited | Information & communication | 2020 |
| Morgan Offshore Wind Holdings Limited | Financial services | 2021 |
| Morgan Offshore Wind Limited | Construction | 2021 |
| Mortgage Private Finance Ltd | Financial services | 2024 |
| Mortgage TCO Limited | Financial services | 2005 |
| Morvan Independent Limited | Real estate | 1999 |
| Morven Offshore Wind Holdings Limited | Financial services | 2021 |
| Morven Offshore Wind Limited | Construction | 2021 |
| Mosaic Marketing Ltd | Professional & scientific | 2025 |
| Motest Limited | Wholesale & retail | 2005 |
| Motocrown Limited | | 1980 |
| Motown International Limited | Real estate | 1976 |
| Mount Vernon Postgraduate Medical Centre | Education | 1991 |
| Mountsides Limited | Professional & scientific | 1995 |
| Mova Hairdressing Ltd | Other services | 2002 |
| Mo`Business Limited | Administrative & support | 2007 |
| MP2 Holdings Limited | Financial services | 2023 |
| MP2 Limited | Real estate | 2023 |
| MR Cheapy Limited | Construction | 1997 |
| MR Kahlon Ltd | Construction | 2025 |
| MRK Financial Management Limited | Professional & scientific | 2017 |
| MRK International Limited | Wholesale & retail | 2000 |
| MRN Creation Limited | Arts & recreation | 2013 |
| MRP Inter Services Limited | Construction | 2024 |
| Msbc Solutions (UK) Ltd | Information & communication | 2004 |