| Mrza Investments Limited | Real estate | 2025 |
| MS Sale Property Development Ltd | Professional & scientific | 2025 |
| MSB Construction Projects Ltd | Administrative & support | 2015 |
| MSI Locums Ltd | Real estate | 2011 |
| MSN Development Ltd | Construction | 2018 |
| Mtga Ltd | Real estate | 2022 |
| MTM Electrical Contractors Limited | Energy | 2014 |
| Mubashar Limited | Health & social care | 2018 |
| Mueezy Solutions Limited | Health & social care | 2023 |
| Muhammad Sarwar Ltd | Health & social care | 2025 |
| Mukhujje PVT Ltd | Health & social care | 2023 |
| Multi-National Investments Limited | Real estate | 2017 |
| Multicare Professional Ltd | Manufacturing | 2026 |
| Multimetric Ltd | Professional & scientific | 2014 |
| Musa (NW) Ltd | Hospitality | 2018 |
| Muse Living UK Limited | Professional & scientific | 2026 |
| Music Interiors Limited | Construction | 2017 |
| Mustang Digital Limited | Professional & scientific | 2012 |
| Musthavestyle Ltd | Wholesale & retail | 2020 |
| Mutiny-Clothing Ltd | Wholesale & retail | 2024 |
| MWG (Northwest) Limited | Construction | 2006 |
| MWH Investments Ltd | Real estate | 2023 |
| My Dementia Ltd | Extraterritorial | 2014 |
| My Expressions Limited | Extraterritorial | 2017 |
| My HR GIG Ltd | Professional & scientific | 2018 |
| My Improvement Network Limited | Extraterritorial | 2016 |
| My Life Software Limited | Information & communication | 2002 |
| My Skin Medics Ltd | Other services | 2021 |
| My Tech World (Leigh) Ltd | Wholesale & retail | 2022 |
| My Traders PVT Ltd | Households | 2023 |
| Mydementia Improvement Network Ltd | Information & communication | 2014 |
| Myles Anthony Limited | Manufacturing | 2013 |
| Myni Jewellery Limited | Manufacturing | 2026 |
| Myolearn Ltd | Education | 2025 |
| Myqol Limited | Information & communication | 2017 |
| MZH Investment Group Limited | Financial services | 2022 |
| MZM Investments Ltd | Real estate | 2015 |
| N & E ORO Smile Ltd | Health & social care | 2021 |
| N D Oliver & Co Limited | Professional & scientific | 1999 |
| N R Brilliant Foody Limited | Hospitality | 2023 |
| N&H Asianwear Ltd | Wholesale & retail | 2024 |
| N.B.P. Management Limited | Households | 1984 |
| N.G. Solutions (GB) Ltd | Information & communication | 2013 |
| NA Kitchen Ltd | Information & communication | 2024 |
| Nachon Digital Limited | Information & communication | 2017 |
| Nadia Residential Ltd | Real estate | 2025 |
| Nadite Ltd | Wholesale & retail | 2022 |
| Nailistix Ltd | Other services | 2025 |
| Nails Training Academy by Ioana Andreiana Ltd | Other services | 2025 |
| Name Tapes Ltd | Manufacturing | 2016 |
| Nami Events Limited | Administrative & support | 2020 |
| Nasir House Medical Limited | Health & social care | 2013 |
| Natchat Productions Ltd | Information & communication | 2011 |
| National Home Move Limited | Real estate | 2019 |
| National Response Team Limited | Administrative & support | 2020 |
| National Will Safe Ltd | Administrative & support | 2004 |
| Natjos Limited | Information & communication | 2012 |
| Natural Software Consultants UK Ltd | Information & communication | 2026 |
| Nature Essence Ltd | Wholesale & retail | 2021 |
| Nayoura Ltd | Wholesale & retail | 2025 |
| NCQ Media Limited | Administrative & support | 2025 |
| NDS International Limited | Education | 2023 |
| Needspeed Ltd | Transport & logistics | 2020 |
| Neel Civil Engineering Services Limited | Construction | 2021 |
| Neesam Consulting Ltd | Professional & scientific | 2024 |
| Neethu Gouri DAS Limited | Health & social care | 2022 |
| Neptic Design Limited | Professional & scientific | 2022 |
| Nessgate Properties Limited | Construction | 1988 |
| Nest and Rest Limited | Real estate | 2024 |
| Netvoya Ltd | Wholesale & retail | 2026 |
| Network Nine Nine Limited | Professional & scientific | 2018 |
| Neuro Monitoring Services Limited | Health & social care | 2019 |
| Neuroassesstogether Ltd | Education | 2025 |
| Neurochange Ltd | Professional & scientific | 2015 |
| Never Standard Limited | Professional & scientific | 2024 |
| Nevom Consultancy Ltd | Professional & scientific | 2023 |
| New Crown Barber Ltd | Other services | 2025 |
| New Life Developments Limited | Construction | 2003 |
| New Nostalgia (Materials) Limited | Construction | 2014 |
| New Thames Transport Services Limited | Transport & logistics | 2011 |
| New Trafford Consulting Limited | Professional & scientific | 2017 |
| New World Loot Ltd | Wholesale & retail | 2026 |
| Newcliffe Stores Ltd | Wholesale & retail | 2025 |
| Newell Brothers Holdings Limited | Financial services | 2025 |
| Newell Tuition Limited | Education | 2015 |
| Newlove Homes Ltd | Real estate | 2020 |
| Newmix Concrete Limited | Manufacturing | 2017 |
| Nexgenops Solutions Ltd | Information & communication | 2024 |
| Nexpath Group Ltd | Wholesale & retail | 2016 |
| Next Elect Ltd | Real estate | 2022 |
| Next Generation AM Technologies Ltd | Administrative & support | 2015 |
| Next Medics Ltd | Information & communication | 2025 |
| Next Steps Mental Healthcare Limited | Health & social care | 2015 |
| Nextbright Property Management Limited | Households | 1988 |
| Nexus Bridge Healthcare Ltd | Health & social care | 2025 |
| NGS4HOMES Ltd | Real estate | 2022 |
| NH Events Ltd | Other services | 2023 |
| NHB Consultancy Ltd | Professional & scientific | 2026 |
| Nibbl Ltd | Information & communication | 2026 |
| Niche Employment Consultants Limited | Administrative & support | 2015 |