| MTX Consulting UK Limited | Information & communication | 2023 |
| Muca Property UK Ltd | Real estate | 2025 |
| Mudge Plus Ltd | Professional & scientific | 2023 |
| Mukhal Property Investments Ltd | Real estate | 2016 |
| Mukhal Property Ltd | Real estate | 2019 |
| Mukhal Property Management Ltd | Real estate | 2020 |
| Multiply Investments Ltd | Real estate | 2016 |
| Multivalent Solutions Limited | Information & communication | 2022 |
| Multivision Productions Limited | | 1983 |
| MUM Said Films Ltd | Information & communication | 2021 |
| Mumport Properties Limited | Real estate | 2022 |
| Mumra Limited | Administrative & support | 2004 |
| Mumson Investments Limited | Real estate | 2021 |
| Mumtaz London Limited | Real estate | 2012 |
| Munisoft Limited | Information & communication | 2007 |
| Munot Developers Limited | Real estate | 2019 |
| Murari (Reading) Limited | Real estate | 2020 |
| Murari Trading Company Limited | Real estate | 2019 |
| Murchan Property Holdings Limited | Real estate | 2024 |
| Musdin Investments Limited | Real estate | 2012 |
| Music & Life Ltd | Education | 2023 |
| Mutual Funding Corporation Ltd | Administrative & support | 2006 |
| MV Kothari Ltd | Information & communication | 2026 |
| MV Occupational Therapy Ltd | Health & social care | 2017 |
| MV Smiles Ltd | Health & social care | 2023 |
| Mv&Co Project Ltd | Professional & scientific | 2021 |
| Mvpc Bookkeeping Limited | Professional & scientific | 2022 |
| MW Management Services Ltd | Professional & scientific | 2024 |
| MWL Consultancy Limited | Professional & scientific | 2018 |
| MWL Group Holdings Limited | Financial services | 2024 |
| MWL Investments Limited | Real estate | 2024 |
| MWT Financial Services Limited | Financial services | 2022 |
| My Braiding Hair Ltd | Other services | 2023 |
| My Dream Kitchen (Pinner) Limited | Wholesale & retail | 2014 |
| My EYE Doctor Ltd | Health & social care | 2023 |
| My Home Sweet Home Services Limited | Health & social care | 2024 |
| My Little Bubba Shreena Limited | Wholesale & retail | 2017 |
| My Music Resource Ltd | Education | 2020 |
| My Nose London Ltd | Health & social care | 2020 |
| My Willow Views Limited | Real estate | 2025 |
| Myaksons Limited | Real estate | 2023 |
| Myaqsa Limited | Construction | 2023 |
| Myaqsa London Limited | Construction | 2024 |
| Myls Accountants Ltd | Professional & scientific | 2010 |
| Mymetal Limited | Extraterritorial | 2024 |
| Myna Management Ltd | Real estate | 2006 |
| Myny Limited | Professional & scientific | 2024 |
| Myriad Real Estate Limited | Real estate | 2023 |
| Mysanitas Ltd | Health & social care | 2022 |
| Mystall Ltd | Wholesale & retail | 2023 |
| MZB Management Limited | Real estate | 2022 |
| N & U Patel Limited | Wholesale & retail | 2003 |
| N Amin Limited | Health & social care | 2024 |
| N G Management Limited | Real estate | 1992 |
| N J Global Limited | Education | 2013 |
| N Jooma Professional Services Ltd | Professional & scientific | 2015 |
| N Lubega Limited | Information & communication | 2011 |
| N Parmar Limited | Health & social care | 2024 |
| N&K Health Ltd | Health & social care | 2025 |
| N.A.C.D. Limited | Professional & scientific | 1996 |
| N.G.A. Building Services Limited | Construction | 2022 |
| N.N Double Glazing Installation and Repairs Ltd | Construction | 2023 |
| N21 Investments Ltd | Real estate | 2023 |
| N3 Investments Limited | Real estate | 2019 |
| N3H4 Ltd | Real estate | 2016 |
| N9 Ltd | Wholesale & retail | 2005 |
| NA Primary Care Limited | Health & social care | 2013 |
| NA1 Construction Limited | Construction | 2024 |
| Nabil Properties Ltd | Real estate | 2023 |
| Nadaid Ltd | Health & social care | 2022 |
| Naik Investments Limited | Real estate | 2017 |
| Nails & Co Limited | Other services | 2010 |
| Naivuli Ltd | Health & social care | 2023 |
| Nakama Limited | Wholesale & retail | 2022 |
| Nama Private Limited | Real estate | 2025 |
| Nama Property Management Limited | Households | 2025 |
| Namco Orthopaedics Ltd | Health & social care | 2026 |
| Namco Properties Ltd | Real estate | 2020 |
| Nanny to the Rescue Ltd | Health & social care | 2015 |
| Napclan (UK) Limited | Wholesale & retail | 1991 |
| Narada Ltd | Professional & scientific | 2010 |
| Narijhiwa Limited | Hospitality | 2024 |
| Narnish Limited | Information & communication | 2015 |
| Nars Holdings Ltd | Financial services | 2026 |
| Nashbarn Limited | Real estate | 1993 |
| Nathan Consulting Services Limited | Information & communication | 2018 |
| National Contracting Services Limited | Construction | 2017 |
| National Lifting Solutions Limited | Construction | 2019 |
| Nations Rock Limited | Professional & scientific | 2025 |
| Natural Infusions Ltd | Other services | 2013 |
| Naturelle M Limited | Other services | 2006 |
| Nautical Supply International Holdings Limited | Financial services | 2019 |
| Nava Traders Limited | Wholesale & retail | 2021 |
| Navaro Holdings Limited | Financial services | 2025 |
| Navmi Ltd | Information & communication | 2024 |
| Naya Collective Limited | Wholesale & retail | 2026 |
| Nayaco Limited | Health & social care | 2015 |
| Nazm London Limited | Wholesale & retail | 2025 |
| NB Development Homes Limited | Real estate | 2020 |
| NB Development Solutions Ltd | Professional & scientific | 2015 |