| MS Items Limited | Wholesale & retail | 2025 |
| MSB Consultancy Limited | Wholesale & retail | 2008 |
| MSB Quality Consultants Ltd | Professional & scientific | 2022 |
| MSD Investment Properties Limited | Real estate | 2022 |
| MSD Propco Limited | Real estate | 2019 |
| MSK Freight Ltd | Transport & logistics | 2025 |
| Mskooner Ltd | Wholesale & retail | 2025 |
| MT Construction Rugby Ltd | Construction | 2026 |
| MTA Contractors Ltd | Transport & logistics | 2022 |
| MTE Marton Limited | Real estate | 2005 |
| Mtech City Ltd | Construction | 2024 |
| MTL Interiors Group Ltd | Financial services | 2019 |
| MTL Solutions (UK) Ltd | Wholesale & retail | 2013 |
| MTV Electrical Contractors Limited | Administrative & support | 2013 |
| MUG Devon Ltd | Hospitality | 2025 |
| Muhaftah and Co Limited | Real estate | 2022 |
| Mulberi Limited | Real estate | 2018 |
| Mulberry Commercial Developments JM Limited | Construction | 2023 |
| Multi Point Constraint Ltd | Agriculture & fishing | 2013 |
| Munachi Limited | Real estate | 2019 |
| Munaro Consultancy Ltd | Professional & scientific | 2023 |
| Murphy Keystone Property Ltd | Real estate | 2026 |
| Murphy Oliver Limited | Information & communication | 2023 |
| Murray, Morgan & Mozart Ltd | Information & communication | 2025 |
| Musasa Properties Ltd | Construction | 2024 |
| Mutasa Geti Ltd | Health & social care | 2023 |
| MVB Pasiv Group Ltd | Construction | 2026 |
| MVF Commercial Limited | Real estate | 2024 |
| MVF Property Solutions Ltd | Real estate | 2023 |
| MVH87 Ltd | Transport & logistics | 2024 |
| MW Elements Ltd | Manufacturing | 2026 |
| MW European Limited | Transport & logistics | 2016 |
| MW Heating Limited | Construction | 2007 |
| MWJ Detailing Ltd | Wholesale & retail | 2026 |
| MWT (Rugby) Limited | Transport & logistics | 2016 |
| MXW Group Limited | Wholesale & retail | 1995 |
| My Greenfingers Ltd | Wholesale & retail | 2025 |
| My Property Searches Ltd | Professional & scientific | 2021 |
| MYA Electrical & Building Services Ltd | Construction | 2024 |
| Mycod Fisheries Ltd | Hospitality | 2019 |
| Mycon Marketing Services Limited | Professional & scientific | 1981 |
| Mycotribe Limited | Manufacturing | 2025 |
| Mynewskin.Ai Limited | Health & social care | 2026 |
| Myphlexit Limited | Information & communication | 2024 |
| Mystic-Trades Ltd | Wholesale & retail | 2024 |
| N & B Enterprises Limited | Real estate | 2003 |
| N Anderson Limited | Transport & logistics | 2009 |
| N Mikeli Construction Limited | Construction | 2025 |
| N W Logistics Limited | Transport & logistics | 2008 |
| N&H Homes Ltd | Real estate | 2021 |
| N.A.A.A Limited | Wholesale & retail | 2018 |
| N.C.T. Computer Services Limited | Extraterritorial | 1989 |
| N.E.J. Stevenson Properties Limited | Real estate | 2005 |
| N.T.P.It Consultancy Ltd | Information & communication | 2017 |
| N3W Homes Limited | Real estate | 2021 |
| Nacho Mission Limited | Manufacturing | 2012 |
| Nacton Communications Limited | Information & communication | 1986 |
| Nadia Transport Ltd | Transport & logistics | 2020 |
| Naegl Ltd | Other services | 2023 |
| Nagella Engineering Services Limited | Professional & scientific | 2019 |
| Naidu Property Services Ltd | Real estate | 2021 |
| Naidu Software Services Ltd | Information & communication | 2011 |
| Nail Art 1 Ltd | Other services | 2023 |
| Nail Artistry by Charlotte Ltd | Wholesale & retail | 2016 |
| Nail Express AJ Ltd | Other services | 2026 |
| Nairabox Limited | Information & communication | 2022 |
| Nancy Thomas Limited | Extraterritorial | 2023 |
| Nandana Solutions Limited | Information & communication | 2022 |
| Nandrey Consulting Ltd | Information & communication | 2019 |
| Nandrey Properties Ltd | Real estate | 2018 |
| Nanoprotect Ltd | Wholesale & retail | 2025 |
| NAR Electrical Group Ltd | Wholesale & retail | 2024 |
| Narrowboat Holdings Ltd | Financial services | 2023 |
| Nathan B Ltd | Transport & logistics | 2024 |
| National Children's Air Ambulance Limited | Health & social care | 2025 |
| National Crossbow Federation of Great Britain | Arts & recreation | 2010 |
| National Roads and Civil Engineering Ltd | Construction | 2025 |
| National Transport Master Ltd | Transport & logistics | 2019 |
| Nationwide Windows (UK) Limited | Extraterritorial | 2010 |
| Nationwide Windows Holding Company Limited | Professional & scientific | 2000 |
| Nationwide Windows Limited | Manufacturing | 1986 |
| Natura Grounds Maintenance Ltd | Administrative & support | 2024 |
| Natural Jamaica Ltd | Wholesale & retail | 2020 |
| Nature Reunion Europe CIC | Administrative & support | 2025 |
| Natures-Pill Ltd | Wholesale & retail | 2025 |
| Naty Ltd | Transport & logistics | 2015 |
| NAV ASH Group Ltd | Hospitality | 2022 |
| Navatron Limited | Administrative & support | 2014 |
| Navi Techno Services Ltd | Information & communication | 2019 |
| NBR (UK) Services Ltd | Information & communication | 2018 |
| NBS Future Ltd | Professional & scientific | 2026 |
| Ncdra Limited | Information & communication | 2025 |
| NCK Logistics Ltd | Transport & logistics | 2024 |
| NCL Development Limited | Construction | 2019 |
| NDT Equipment Limited | Professional & scientific | 2022 |
| Neales Waste Management Limited | Water & waste | 1991 |
| Nebula AI Business Consulting Ltd | Wholesale & retail | 2025 |
| Need the LOO Hire Limited | Water & waste | 2018 |
| Neethu Ltd | Wholesale & retail | 2025 |
| Negri Bossi Limited | Manufacturing | 1999 |