| Mohamed Family Investment Company (Mfic) Ltd | Financial services | 2023 |
| Mohamedkazim S Bhaloo Limited | Other services | 2011 |
| Mohd Jeffri Limited | Administrative & support | 2013 |
| Moheeb Ltd | Professional & scientific | 2015 |
| Mohit Limited | Professional & scientific | 2009 |
| Mohmand Immigration Legal Services Ltd | Professional & scientific | 2024 |
| MOI Cleaning Services Ltd | Other services | 2011 |
| MOI Consultancy PVT Ltd | Professional & scientific | 2023 |
| Moiran Investment Ltd | Real estate | 2019 |
| Moisa Financial Ltd | Financial services | 2019 |
| Moisa Limited | Information & communication | 2014 |
| MOK Solutions Limited | Information & communication | 2008 |
| Mokar Properties Limited | Real estate | 2005 |
| Moksh Clothing London Limited | Wholesale & retail | 2013 |
| Moksh Funeral Care Limited | Other services | 2014 |
| Moksha Consultants Limited | Information & communication | 2017 |
| Moksha Design Limited | Information & communication | 2024 |
| Mokutan Technologies Ltd | Information & communication | 2022 |
| Mole Engineering Limited | Manufacturing | 1985 |
| Molecule Pharma Limited | Professional & scientific | 2022 |
| MOM Motors Ltd | Wholesale & retail | 2026 |
| Momand Group Ltd | Wholesale & retail | 2024 |
| Mombay Limited | Wholesale & retail | 2024 |
| Moment Story Media Ltd | Professional & scientific | 2025 |
| Momentum Funding Ltd | Wholesale & retail | 2019 |
| Momentum Global Services Limited | Administrative & support | 2026 |
| Momentum Media 172 Limited | Professional & scientific | 2025 |
| Momomore Ltd | Hospitality | 2025 |
| Moms Against Clutter Ltd | Wholesale & retail | 2025 |
| MON Food and Wine Ltd | Other services | 2023 |
| Mon&Tech Ltd | Professional & scientific | 2019 |
| Mona (London) Foods Limited | Hospitality | 2017 |
| Monacoe UK Ltd | Administrative & support | 2014 |
| Monaford Ltd | Real estate | 2020 |
| Monarch Commercial Limited | Real estate | 1995 |
| Monarchy Roofing Limited | Construction | 2025 |
| Monastic Consultant Limited | Wholesale & retail | 2024 |
| Money Magnified Ltd | Information & communication | 2025 |
| Moneyman Finserve Ltd | Professional & scientific | 2022 |
| Monica Limited | Financial services | 2015 |
| Monica Moon Ltd | Extraterritorial | 2023 |
| Monique Consultancy (UK) Limited | Professional & scientific | 2013 |
| Monkey Cave Limited | Wholesale & retail | 2019 |
| Monkey Creation Limited | Professional & scientific | 2026 |
| Monks Property Services Limited | Real estate | 2020 |
| Monlleo Holdings Limited | Health & social care | 2024 |
| Mono Building Ltd | Construction | 2018 |
| Monocouche Render Supplies Ltd | Construction | 2021 |
| Monocouche Render Systems Ltd | Construction | 2021 |
| Monokeros BIO Ltd | Professional & scientific | 2023 |
| Monolux Ltd | Construction | 2014 |
| Monric Limited | Health & social care | 2009 |
| Monrok Ltd | Construction | 2015 |
| Monster Pizza Ltd | Hospitality | 2024 |
| Mont Magic Ltd | Wholesale & retail | 2025 |
| Montague Consultancy Limited | Professional & scientific | 2019 |
| Montague Ventures Limited | Professional & scientific | 2006 |
| Montcove Limited | Financial services | 2026 |
| Montdale Ltd | Real estate | 2013 |
| Montgomery and Churchill Ltd | Wholesale & retail | 2025 |
| Montone & Molnar Ltd | Hospitality | 2023 |
| Montrose Alliance Ltd | Real estate | 2019 |
| Monty Supermarket Limited | Construction | 2016 |
| Monument Construction Ltd | Construction | 2014 |
| Monzoro Ltd | Wholesale & retail | 2024 |
| Moody Foody Limited | Hospitality | 2018 |
| Moon & London Ltd | Professional & scientific | 2023 |
| MOON28 Ltd | Wholesale & retail | 2023 |
| Mooncastle Limited | Hospitality | 2010 |
| Moonflower Limited | Financial services | 2021 |
| Moonlake Digital Rights Ltd | Information & communication | 2021 |
| Moonlake Entertainment Rights Limited | Information & communication | 2012 |
| Moonlight Fresh Ltd | Wholesale & retail | 2021 |
| Moonline Property Limited | Real estate | 2017 |
| Moonrise Holdings Ltd | Financial services | 2026 |
| Moonstone Property Ltd | Financial services | 2025 |
| Moonstride Ltd | Information & communication | 2019 |
| Moontide Investments Ltd | Real estate | 2018 |
| Moore LEE Ltd | Real estate | 2021 |
| Moorgate Essentials Limited | Wholesale & retail | 2015 |
| Moose Internet Services Limited | Information & communication | 2000 |
| Mooyaa Limited | Real estate | 2020 |
| MOR Design & Build Limited | Manufacturing | 2023 |
| Moradi Group Ltd | Real estate | 2026 |
| Moraine Limited | Administrative & support | 2017 |
| Moran Delacey Limited | Professional & scientific | 2014 |
| Morange Limited | Wholesale & retail | 2020 |
| Morasiya Group Ltd | Hospitality | 2024 |
| More Area Limited | Financial services | 2021 |
| More Engineering Limited | Professional & scientific | 2005 |
| More Than One Limited | Professional & scientific | 2011 |
| Moreorgo Ltd | Wholesale & retail | 2025 |
| Moreton Consultants Limited | Information & communication | 1998 |
| Moreyeah Foods Limited | Manufacturing | 2024 |
| Morfox Ltd | Construction | 2025 |
| Morgan K.S Ltd | Professional & scientific | 2016 |
| Morgan Phillips Properties (UK) Limited | Real estate | 2024 |
| Morgan Street (Overseas) Limited | Arts & recreation | 1998 |
| Morgan Street Limited | Arts & recreation | 1998 |
| Morganite Trading Ltd | Wholesale & retail | 2015 |