| MK40 Architects Limited | Professional & scientific | 2009 |
| MK40 Autos Ltd | Wholesale & retail | 2018 |
| MK40 Store Ltd | Wholesale & retail | 2026 |
| Mk:U Limited | Education | 2018 |
| MKB Invest Ltd | Wholesale & retail | 2015 |
| Mkbasketballfoundation | Arts & recreation | 2020 |
| Mkfgoods Limited | Wholesale & retail | 2023 |
| Mkfitters Limited | Construction | 2020 |
| MKG Store Ltd | Wholesale & retail | 2020 |
| MKM Carpentry Ltd | Construction | 2024 |
| Mkprodetail MK Ltd | Wholesale & retail | 2023 |
| ML Liveries Ltd | Arts & recreation | 2026 |
| Mlgl Property Limited | Real estate | 2025 |
| Mlgl Ventures Limited | Administrative & support | 2025 |
| MLS Ventures Ltd | Wholesale & retail | 2025 |
| MM Beauty & Nails Ltd | Other services | 2025 |
| MM Site Clearances Ltd | Administrative & support | 2021 |
| MM Tanning Ltd | Other services | 2025 |
| Mmax Gym Limited | Arts & recreation | 2024 |
| MMF Catering Limited | Hospitality | 2025 |
| MMG Property Ltd | Households | 2025 |
| MMJ Housing Ltd | Real estate | 2018 |
| MMK Medical Ltd | Health & social care | 2022 |
| MML Properties Limited | Real estate | 2003 |
| Mmmvehicleservices Limited | Wholesale & retail | 2025 |
| MMQ Holdings Ltd | Real estate | 2025 |
| MMR Property Management Limited | Real estate | 2021 |
| MN Commercial Constultants Ltd | Extraterritorial | 2018 |
| MNA Investment Group Ltd | Real estate | 2019 |
| MNA Property Management Ltd | Real estate | 2017 |
| MNA Property Solutions Limited | Real estate | 2022 |
| MNA Software Solutions Limited | Information & communication | 2021 |
| MNHDRIVER4U Ltd | Administrative & support | 2025 |
| Mnico Ltd | Transport & logistics | 2021 |
| MO ALI Holdings Ltd | Other services | 2021 |
| Moao Services Ltd | Information & communication | 2014 |
| Mobally Ltd | Administrative & support | 2020 |
| Mobile Aesthetics Ltd | Other services | 2024 |
| Mobile Freezer Rentals Limited | Administrative & support | 1988 |
| Mobile Locksmith Domestic & Auto Ltd | Other services | 2012 |
| Mobility Policy LAB Limited | Professional & scientific | 2018 |
| Mobility Support Services Limited | Professional & scientific | 2018 |
| Model Products Limited | Professional & scientific | 1994 |
| Moderate Motors Ltd | Wholesale & retail | 2020 |
| Modern Architecture Workshop Ltd | Professional & scientific | 2016 |
| Modern Casuals Ltd | Extraterritorial | 2013 |
| Modern Fencing Ltd | Wholesale & retail | 2023 |
| Modessa Construction Ltd | Construction | 2022 |
| Modifix Global Limited | Wholesale & retail | 2025 |
| Moesha Ltd | Health & social care | 2020 |
| Moetech Automation Ltd | Professional & scientific | 2023 |
| MOG Limited | Wholesale & retail | 2024 |
| Moggerhanger Park Limited | Hospitality | 2003 |
| Mohak Ltd | Information & communication | 2013 |
| Mohan's Sweet Centre Limited | Hospitality | 2013 |
| Mohit Klair Limited | Hospitality | 2022 |
| Moises Modern Limited | Real estate | 2025 |
| Mojo Advisory Limited | Professional & scientific | 2020 |
| Molatopal Limited | Hospitality | 2015 |
| Moliver Wells Ltd | Real estate | 2026 |
| Molly Waller Beauty Ltd | Other services | 2025 |
| Molly's Limited | Wholesale & retail | 2002 |
| Mologic Ltd. | Professional & scientific | 2003 |
| Molten Chees Limited | Hospitality | 2025 |
| Molyneux Jones Funeral Directors Limited | Other services | 2015 |
| Momchil Ltd | Real estate | 2026 |
| Moment PUR Event and Bridal Limited | Hospitality | 2024 |
| Momentum Broadcast Ltd | Information & communication | 2024 |
| Momentum Management Ltd | Professional & scientific | 2024 |
| Momentum Media & Broadcast Ltd | Information & communication | 2026 |
| Momi Properties Limited | Real estate | 2024 |
| Monaco Ltd | Wholesale & retail | 2026 |
| Monal Group Ltd | Hospitality | 2024 |
| Monarch Agricultural Investments Ltd | Agriculture & fishing | 2021 |
| Mondair Property Developers Ltd. | Construction | 1993 |
| Mondo Entertainment Ltd | Manufacturing | 2020 |
| Moneva Wholesale Ltd | Wholesale & retail | 2026 |
| Money Lounge Limited | Arts & recreation | 2021 |
| Money Smarties Limited | Other services | 2022 |
| Mongoue Ltd | Health & social care | 2020 |
| Monica Beauty Studio Limited | Other services | 2022 |
| Monica Cueva Moya Limited | Health & social care | 2014 |
| Monico Tunley Limited | Professional & scientific | 2009 |
| Monika Accountant Ltd | Professional & scientific | 2014 |
| Monika's Nails and Beauty Ltd | Other services | 2025 |
| Monkeypunk Rubber Ltd | Wholesale & retail | 2020 |
| Monmouth Lettings Ltd | Real estate | 2024 |
| Monssuma Properties Ltd | Real estate | 2021 |
| Montague Reinstatement Limited | Construction | 2018 |
| Monte Cristo Trading Ltd | Construction | 2022 |
| Monte Ecom Ltd | Wholesale & retail | 2026 |
| Monte Medical Limited | Health & social care | 2021 |
| Monteiro Solar Generation Ltd | Energy | 2025 |
| Montgomery Media Limited | Financial services | 2011 |
| Monumental Events Ltd | Administrative & support | 2024 |
| Mooeys Franchise Limited | Other services | 2018 |
| Mooeys Limited | Other services | 2013 |
| Mooi Ceramics Co Ltd | Wholesale & retail | 2020 |
| Moon Haus Limited | Manufacturing | 2026 |
| Moon Technologies Limited | Information & communication | 2007 |