| Mpro Consulting Ltd | Professional & scientific | 2024 |
| MR Baldwin Builders Ltd | Construction | 2014 |
| MR BIT Ltd | Other services | 2016 |
| MR Bumble Holdings Ltd | Financial services | 2024 |
| Mrbg Limited | Professional & scientific | 2009 |
| Mrcinstallations Limited | Construction | 2019 |
| Mreps Trustees (NO 84) Limited | Extraterritorial | 2003 |
| MRM Contractors Limited | Construction | 2025 |
| MS Security Ltd | Administrative & support | 2024 |
| Msap Services Ltd | Professional & scientific | 2026 |
| MSF Construction Group Ltd | Construction | 2026 |
| MSJ Jewellery Services Ltd | Other services | 2010 |
| MSK Health Solutions Ltd | Health & social care | 2017 |
| MSP Monarch Enterprise Ltd | Administrative & support | 2025 |
| MT Contracting Ltd | Construction | 2018 |
| Mtpg Ltd | Administrative & support | 2026 |
| Mulberry Architecture Ltd | Professional & scientific | 2017 |
| Mulberry Marine Experiences C.I.C. | Arts & recreation | 2005 |
| Mulberry Mortgages Ltd | Financial services | 2024 |
| Mulgrave Financial Services Limited | Financial services | 2018 |
| Multitude Limited | Real estate | 1982 |
| Munneries Limited | Wholesale & retail | 2013 |
| Muntham Farm (Findon) Limited | Agriculture & fishing | 1978 |
| Muntham Farm LLP | | 2013 |
| Muscovy Management Ltd | Real estate | 2019 |
| Muse Aesthetics Training Limited | Education | 2026 |
| Museum Shops Ltd | Wholesale & retail | 2017 |
| Music of Life Limited | Information & communication | 1995 |
| Musketeer Ventures Ltd | Real estate | 2021 |
| Mustard Seed Publishing Ltd | Administrative & support | 2006 |
| MV Expo Ltd | Administrative & support | 2018 |
| MVR Property Ltd | Real estate | 2017 |
| MW Emdr Limited | Health & social care | 2018 |
| Mw-Uk Ltd | Wholesale & retail | 2020 |
| MWP Enterprises Limited | Professional & scientific | 2011 |
| My African Beauty Ltd | Wholesale & retail | 2021 |
| My Babymanual Limited | Information & communication | 2017 |
| My Green Garden Limited | Wholesale & retail | 2010 |
| My Home Heros Ltd | Administrative & support | 2025 |
| My In-House Legal Limited | Professional & scientific | 2023 |
| My Student LET Limited | Real estate | 2011 |
| Mycora Ltd | Information & communication | 2025 |
| Mydidimo UK Ltd | Information & communication | 2020 |
| Myles Brav Holdings Ltd | Financial services | 2024 |
| Mypensionid Limited | Other services | 2019 |
| Myrtle Media and Marketing LLP | | 2010 |
| Myrtle Tree Estates Limited | Real estate | 2003 |
| N & R Properties (Spain) Ltd | Real estate | 2025 |
| N & T Properties Ltd | Real estate | 2018 |
| N J S Brickwork Ltd. | Construction | 1998 |
| N J S Group Limited | Professional & scientific | 2002 |
| N W Leisure Ltd | Arts & recreation | 2019 |
| N&Dbulbeck Investments Ltd | Financial services | 2024 |
| N-Visage Productions Limited | Information & communication | 2002 |
| N.P.J. Cripps Surgery Limited | Health & social care | 2003 |
| Nadhouse Ltd | Hospitality | 2013 |
| Nadira Property Ltd | Real estate | 2024 |
| Nairod IT Limited | Information & communication | 2025 |
| Naked Innovation Management Ltd | Professional & scientific | 2019 |
| Nakshatraa Ltd | Wholesale & retail | 2025 |
| Namaka Capital Limited | Professional & scientific | 2026 |
| Nambudakam Limited | Real estate | 2016 |
| Napier Partnership Limited | Professional & scientific | 2001 |
| Napier Trustees Limited | Administrative & support | 2022 |
| Nash Consultancy Ltd | Professional & scientific | 2024 |
| Natalia Richardson Limited | Health & social care | 2014 |
| Natalie Ewens Hair Ltd | Other services | 2026 |
| National Garages UK Limited | Households | 2023 |
| National Land and Property Owners Alliance Ltd | Information & communication | 2024 |
| Nationwide Installations Ltd | Other services | 2021 |
| Natta Productions Ltd | Information & communication | 2019 |
| Natural Balance Hoof Care Limited | Administrative & support | 2003 |
| Natural Land Management Limited | Administrative & support | 2009 |
| Natural Life CBD Ltd | Wholesale & retail | 2018 |
| Natural Selection Consultancy Services Ltd | Professional & scientific | 2007 |
| Natural Selection Developments Ltd | Construction | 2020 |
| Natural Selection Holdings Ltd | Financial services | 2020 |
| Natural Selection Properties Ltd | Real estate | 2024 |
| Nature Based Collaborative Solutions C.I.C. | Professional & scientific | 2021 |
| Nautilus Pools Limited | Construction | 2006 |
| Nautra Ltd | Wholesale & retail | 2021 |
| Naval Dependants Income and Assurance Trust Limited | Financial services | 1976 |
| Navigators Marine Service Centre Limited | Administrative & support | 2020 |
| Naylor Accountancy Services (Chichester) Limited | Professional & scientific | 2007 |
| NB Waste Disposals Ltd | Water & waste | 2024 |
| NBH Management Ltd | Wholesale & retail | 2022 |
| Nbvp Ltd | Professional & scientific | 2025 |
| NDT Consultancy Services Ltd | Professional & scientific | 2009 |
| NE Events Limited | Arts & recreation | 2022 |
| Neame Sutton Limited | Administrative & support | 2010 |
| Neat Fleet Cleaners Ltd | Administrative & support | 2024 |
| Neatscape Limited | Administrative & support | 2006 |
| Neds Holding Group Limited | Financial services | 2024 |
| Need a Field Ltd | Real estate | 2017 |
| NEEK57 Ltd | Wholesale & retail | 2019 |
| Neilor Limited | Administrative & support | 2007 |
| Nelson Engineering Services Ltd | Manufacturing | 2007 |
| Nest Down Limited | Real estate | 2024 |
| Nest Home Improvements Ltd | Construction | 2026 |
| Nest Partnerships Ltd | Real estate | 2026 |