| Morethanbathroom Ltd | Construction | 2022 |
| Morfeas Ltd | Professional & scientific | 2020 |
| Morgan Advanced Materials PLC | Professional & scientific | 1934 |
| Morgan Electro Ceramics Limited | Extraterritorial | 1910 |
| Morgan Europe Holding Limited | Financial services | 1990 |
| Morgan European Finance Limited | Professional & scientific | 2015 |
| Morgan Finance Management Limited | Professional & scientific | 2016 |
| Morgan Group Pension Scheme Trustees Limited | Financial services | 2019 |
| Morgan Group Senior Staff Pension Trustees Limited | Financial services | 2019 |
| Morgan Holdings Limited | Professional & scientific | 1985 |
| Morgan International Holding Limited | Financial services | 2017 |
| Morgan North America Holding Limited | Professional & scientific | 2013 |
| Morgan Trans Limited | Professional & scientific | 1990 |
| Morganite Carbon Limited | Professional & scientific | 1961 |
| Morganite Crucible Limited | Professional & scientific | 1987 |
| Morganite Special Carbons Limited | Extraterritorial | 1971 |
| Mostly Boxes Antiques Limited | Wholesale & retail | 2012 |
| MOTEL8 Ltd | Administrative & support | 2017 |
| Motorvision Limited | Wholesale & retail | 2014 |
| Motorvision Transport Ltd | Transport & logistics | 2019 |
| Mount ASH Associates Ltd | Professional & scientific | 2026 |
| Mount ASH Group Ltd | Professional & scientific | 2026 |
| Mountbatten House (Serviced Offices) Limited | Real estate | 1997 |
| Mountbatten Square Investments Limited | Real estate | 1997 |
| Move Mountains Limited | Administrative & support | 2012 |
| Mowaq Ltd | Other services | 2016 |
| MPB Lighting Ltd | Information & communication | 2021 |
| Mpforrest Consulting Ltd | Professional & scientific | 2013 |
| MSP Phones Limited | Information & communication | 2021 |
| Msys Solutions Limited | Information & communication | 2016 |
| MT Design Ltd | Professional & scientific | 2007 |
| MTN Solutions Ltd | Construction | 2008 |
| MTS Recruitment Limited | Administrative & support | 2024 |
| Multi - Stetic Ltd | Real estate | 2013 |
| MULTIM3D Ltd | Information & communication | 2022 |
| Mumsmeetup.Com Limited | Information & communication | 2016 |
| Muscle Marketing Limited | Other services | 2021 |
| Muster Investments Limited | Real estate | 2024 |
| MVR Entertainment Ltd | Information & communication | 2023 |
| My Consulting Partner Limited | Professional & scientific | 2015 |
| My Controller Franchise Limited | Professional & scientific | 2013 |
| My Controller Holdings Limited | Financial services | 2024 |
| My Controller Limited | Professional & scientific | 2003 |
| My First Pony Ltd | Education | 2025 |
| My Other Space Ltd | Hospitality | 2022 |
| My Outdoor Adventure CIC | Arts & recreation | 2022 |
| My Plus Consulting Limited | Professional & scientific | 2005 |
| My Specialist GP Ltd | Health & social care | 2017 |
| Mycoli Ltd | Extraterritorial | 2025 |
| Mydang's Nails Limited | Other services | 2024 |
| Mygp Ltd | Health & social care | 2017 |
| Mytrade Limited | Wholesale & retail | 2022 |
| Mzkaali Ltd | Wholesale & retail | 2024 |
| N Boparai Consulting Ltd | Professional & scientific | 2022 |
| N&G Mining Limited | Mining & quarrying | 2022 |
| N-Shakeel IT Consultancy Limited | Information & communication | 2024 |
| Nagwa Limited | Education | 2016 |
| Nail IT Education Ltd | Education | 2026 |
| Nami Healthy Food Ltd | Wholesale & retail | 2020 |
| Namnori Limited | Professional & scientific | 2023 |
| Nanny Scout Limited | Administrative & support | 2014 |
| Naprta Wellness Ltd | Health & social care | 2023 |
| NAR Consultancy Services Ltd | Arts & recreation | 2022 |
| Naranjo Corporation Limited | Construction | 2001 |
| Narclothes Ltd | Wholesale & retail | 2019 |
| Nash Trade House Management Company Limited | Households | 2018 |
| National Productivity Centre Limited | Information & communication | 2025 |
| Naurs Ltd | Health & social care | 2023 |
| Nautilus Equities Limited | Professional & scientific | 2023 |
| Navigation Films Ltd | Information & communication | 2015 |
| Navy Lily Limited | Extraterritorial | 2018 |
| Naxn Ltd | Professional & scientific | 2008 |
| Nayv Ltd | Administrative & support | 2024 |
| NB for ALL Ltd | Arts & recreation | 2025 |
| NB Music GB Ltd | Administrative & support | 2018 |
| NCP Centre Limited | Professional & scientific | 2026 |
| Ndcinema Limited | Professional & scientific | 2007 |
| Neas Energy Limited | Energy | 2009 |
| Neat Gardens (Domestic) Ltd | Administrative & support | 2018 |
| Neat Gardens Limited | Administrative & support | 2018 |
| Needlebay Systems Limited | Manufacturing | 2020 |
| Neil Holland Financial Services Ltd | Financial services | 2015 |
| Neil M Macfarlane Ltd | Other services | 2024 |
| Neilson Financial Services Limited | Financial services | 2012 |
| Neilson Funeral Planning Limited | Other services | 2023 |
| Neilson International Limited | Financial services | 2021 |
| Neilson Place Ltd | Financial services | 2020 |
| Neithea Consulting Ltd | Professional & scientific | 2025 |
| Nelson Property Services Ltd | Real estate | 2017 |
| Nelson Robinson Learning Consultancy Limited | Professional & scientific | 2009 |
| Nemuca Limited | Information & communication | 2013 |
| Neogreen Ltd | Professional & scientific | 2021 |
| Nest Homecare Limited | Health & social care | 2016 |
| Netapp Ireland Ltd | Information & communication | 2025 |
| Netapp UK Holdings Limited | Financial services | 2022 |
| Netapp UK Ltd | Wholesale & retail | 1994 |
| Nethlion Ltd | Wholesale & retail | 2024 |
| Network & Cloud Solutions UK Ltd | Information & communication | 2023 |
| Neural Reef Ltd | Information & communication | 2015 |
| Neurobridge Limited | Information & communication | 2023 |