| Movision Film Distributors Limited | Information & communication | 2003 |
| MPH & Associates Limited | Administrative & support | 2010 |
| Mphj Consulting & Services Limited | Information & communication | 2014 |
| Mprc Consultants Limited | Professional & scientific | 2014 |
| MPS Manager Ltd | Information & communication | 2025 |
| MPS South Limited | Professional & scientific | 2017 |
| MRA Construction Ltd | Construction | 2016 |
| Mrad Limited | Professional & scientific | 2025 |
| MRC E-Commerce Ltd | Wholesale & retail | 2023 |
| Mrjz Gallery Limited | Health & social care | 2024 |
| MRL Solutions Ltd | Professional & scientific | 2023 |
| Msconsult&Advisory Ltd | Professional & scientific | 2025 |
| MSK Logistics Ltd | Transport & logistics | 2000 |
| MSK Properties Ltd | Real estate | 2006 |
| MSL Engineering Integrity Systems Limited | Professional & scientific | 1999 |
| MSL Medical Services Limited | Financial services | 2012 |
| Msmd Consulting Limited | Professional & scientific | 2016 |
| Msopc | Other services | 2009 |
| Msouthern Consulting Ltd | Information & communication | 2014 |
| MTC Commercial Ltd | Real estate | 2020 |
| MTI Engineering Ltd | Manufacturing | 2013 |
| Mtshare Ltd | Information & communication | 2026 |
| MUD Monsters Run Limited | Arts & recreation | 2014 |
| Muir Investments Limited | Manufacturing | 2002 |
| Mulled Ltd | Information & communication | 2024 |
| Multay International Limited | Wholesale & retail | 1990 |
| Multi Property & Ground Maintenance Ltd. | Households | 2015 |
| Multiframe Construction Ltd. | Construction | 2017 |
| Multipractice Cloud Limited | Extraterritorial | 2010 |
| Multis Services Limited | Professional & scientific | 2017 |
| Mundane Crafts Ltd | Manufacturing | 2025 |
| Mundial Consulting Limited | Information & communication | 2005 |
| Municipal Security Limited | Wholesale & retail | 1988 |
| Municipal Waste Recycling Limited | Water & waste | 2015 |
| Music at Plush Ltd | Arts & recreation | 2007 |
| Mutha Hood Limited | Wholesale & retail | 2017 |
| MVD Training Ltd | Professional & scientific | 2023 |
| MVR Consultancy Limited | Health & social care | 2012 |
| MW and Associates Limited | Information & communication | 2002 |
| MW BH Ltd | Real estate | 2026 |
| MW2 Ltd. | Professional & scientific | 2015 |
| MX2 Electrical Limited | Construction | 2024 |
| Mxcode Limited | Information & communication | 2022 |
| My Adhd Coach Limited | Other services | 2025 |
| My Choice Children's Homes Limited | Health & social care | 1999 |
| My Choice Group Limited | Health & social care | 2004 |
| My Hosting Bubble Limited | Extraterritorial | 2015 |
| My Little Scents Limited | Wholesale & retail | 2014 |
| My Local Bookkeeper Ltd | Professional & scientific | 2025 |
| My London Care Ltd | Health & social care | 2023 |
| My MOT Group Ltd | Professional & scientific | 2024 |
| My Online Fitness Ltd | Arts & recreation | 2020 |
| Mycare Services Ltd | Health & social care | 2007 |
| Myland Geomatics Ltd | Professional & scientific | 2014 |
| Myndset Ltd | Wholesale & retail | 2026 |
| Mystus Ltd | Wholesale & retail | 2023 |
| N E Gosset Ltd | Health & social care | 2003 |
| N G (Personnel Services) Limited | Administrative & support | 2003 |
| N J S Installations Limited | Construction | 2015 |
| N Langdon Consulting Limited | Professional & scientific | 2019 |
| N&J Pest Control Ltd | Administrative & support | 2025 |
| N/A'An Kuse | Professional & scientific | 2009 |
| Naduthala Care Ltd | Health & social care | 2025 |
| Nails-Luxe Ltd | Wholesale & retail | 2021 |
| NAM Property Group Ltd | Real estate | 2025 |
| Nandv Estates LLP | | 2011 |
| Nandv Media LLP | | 2010 |
| Narex Limited | Professional & scientific | 2006 |
| National Integration Hub Limited | Professional & scientific | 2025 |
| National Parking Platform Limited | Transport & logistics | 2025 |
| Natter Ventures Ltd | Professional & scientific | 2014 |
| Natural Angle Ltd | Manufacturing | 2006 |
| Nature Healing Nature Limited | Other services | 2014 |
| Nautic Limited | Information & communication | 2023 |
| Navigate North Ltd | Professional & scientific | 2025 |
| Navigate Video Ltd | Information & communication | 2015 |
| Ndlovu Limited | Agriculture & fishing | 2003 |
| NDS Nutrition Ltd | Wholesale & retail | 2022 |
| NE Adventures Limited | Information & communication | 2023 |
| Nebulogiq Ltd | Information & communication | 2025 |
| Neelis Consulting Limited | Professional & scientific | 2025 |
| Neil G Farley Dental Laboratory Limited | Manufacturing | 2002 |
| Neil Griffiths Publications Ltd | Professional & scientific | 2017 |
| Neil Spiers Limited | Construction | 2017 |
| Neilbrewer Limited | Real estate | 2013 |
| Nells Property Limited | Real estate | 2025 |
| Neomode Ltd | Information & communication | 2015 |
| Neptune Scaffolding Limited | Construction | 2021 |
| Nest Architecture Limited | Professional & scientific | 2026 |
| NET & Telligent Ltd | Manufacturing | 2019 |
| NET Sheriff Limited | Professional & scientific | 2001 |
| NET Zero Carbon Developments Ltd | Construction | 2021 |
| Never Full Limited | Hospitality | 2025 |
| New Acres Limited | Water & waste | 1991 |
| New Brighton Sushi Ltd | Hospitality | 2020 |
| New England Workshop Limited | Construction | 2008 |
| New ERA Carpentry Ltd | Construction | 2024 |
| New Horsham Sushi Ltd | Hospitality | 2018 |
| New House Farm (Twineham) Limited | Agriculture & fishing | 1964 |
| New Wave Studio Limited | Information & communication | 2012 |