| Murphy Grace Peta Ltd | Wholesale & retail | 2026 |
| MUS Consultancy Ltd | Professional & scientific | 2022 |
| Musictank Ltd | Professional & scientific | 2019 |
| Musilian Limited | Information & communication | 2024 |
| Muslim Outreach | Education | 2009 |
| Muswell Bourne Consulting Limited | Professional & scientific | 2014 |
| Muswell Park Properties Limited | Real estate | 2013 |
| MV Coach Hire Limited | Transport & logistics | 2024 |
| MV Crystal Properties Ltd | Real estate | 2024 |
| Mvleg Holdings Limited | Administrative & support | 2026 |
| Mvltz Holdings Limited | Administrative & support | 2025 |
| MW London Property Solutions Ltd | Construction | 2019 |
| Mximd Pictures Ltd | Professional & scientific | 2022 |
| My Bento Ltd | Professional & scientific | 2022 |
| My Cover Ltd | Financial services | 2018 |
| My Fitlens Ltd | Other services | 2023 |
| My Property Empire Limited | Real estate | 2015 |
| My Property Experience Ltd | Real estate | 2019 |
| My Restaurant Empire Limited | Hospitality | 2017 |
| My Roofing Services Ltd | Construction | 2023 |
| Mycake Limited | Information & communication | 2007 |
| Mypclabb Ltd | Wholesale & retail | 2025 |
| Mysterix Limited | Information & communication | 2025 |
| MZ Market Access Consulting Ltd | Professional & scientific | 2022 |
| N&K (Apparel) Limited | Wholesale & retail | 2024 |
| N.A.K. (Management Services) Ltd. | Other services | 1988 |
| N.A.K. Property Services Ltd | Real estate | 2020 |
| N.A.T.S Construction Ltd | Construction | 2024 |
| Naavi Nyasa Ltd | Real estate | 2026 |
| Nabor Limited | Information & communication | 2026 |
| Nadia Nutrition Limited | Hospitality | 2019 |
| Naiksons Infotech Limited | Information & communication | 2024 |
| Naked Eating Limited | Health & social care | 2020 |
| Namaste Kingston CIC | Administrative & support | 2023 |
| Namaste Surbiton Ltd | Hospitality | 2024 |
| Nancy G. Investment Company Ltd | Professional & scientific | 2020 |
| Nanic Technologies Ltd | Information & communication | 2024 |
| Napkin Limited | Information & communication | 2020 |
| Narmis Services Ltd | Professional & scientific | 2023 |
| Narpoint Ltd | Professional & scientific | 2026 |
| Narrativ Ltd | Other services | 2016 |
| Nasa Solutions Ltd | Information & communication | 2022 |
| Nass (UK) Limited | Hospitality | 2012 |
| Nasser & Sons Ltd | Administrative & support | 2015 |
| Nathan Coaches Ltd | Administrative & support | 2011 |
| Natures Way Limited | Real estate | 2023 |
| Navam Property Ltd | Real estate | 2012 |
| NAVIG8 Partners Ltd | Professional & scientific | 2026 |
| NB: Studio Limited | Administrative & support | 1999 |
| ND Creative Studio Limited | Professional & scientific | 2020 |
| NDC Finance Ltd | Professional & scientific | 2024 |
| NDK (People & Business Partner) Ltd | Administrative & support | 2026 |
| NDK Europe Limited | Wholesale & retail | 1988 |
| Neanka Limited | Real estate | 2020 |
| Nearform UK Limited | Information & communication | 2018 |
| Ned-Intr Ltd | Construction | 2026 |
| Nedv Ltd | Real estate | 2025 |
| Neil Brady Ltd | Wholesale & retail | 2021 |
| NEO NET Retailers Ltd | Wholesale & retail | 2025 |
| Neonvoxel Ltd. | Information & communication | 2017 |
| Neos Creative Limited | Professional & scientific | 2000 |
| Nephthysillustrated Ltd | Arts & recreation | 2022 |
| Nerea Artificial Intelligence Services Ltd | Information & communication | 2018 |
| Nesbro Limited | Real estate | 2011 |
| Network Healthcare (Herts) Ltd | Administrative & support | 2018 |
| Neuroworks Occupational Therapy Limited | Health & social care | 2015 |
| Neutrinox Limited | Wholesale & retail | 2021 |
| Nevins Freelance Limited | Professional & scientific | 2011 |
| New Angles Ltd | Professional & scientific | 2019 |
| New Brand Associates Limited | Agriculture & fishing | 2011 |
| New Dialogue | Public administration | 2013 |
| New Gelato Passione Limited | Manufacturing | 2025 |
| New Leaf Learning Ltd | Education | 2012 |
| New Paradigm Publishing Limited | Information & communication | 2013 |
| New Projects Consultants Ltd | Professional & scientific | 2014 |
| New Start Fresh Start Ltd | Professional & scientific | 2004 |
| Newburgh Holdings London Limited | Households | 2024 |
| Newcastle Chiropractic Limited | Health & social care | 2007 |
| Newframes Limited | Wholesale & retail | 2018 |
| Newhaus Ventures Ltd | Professional & scientific | 2024 |
| Newhealth Limited | Professional & scientific | 2001 |
| Newin Beauty Studios Ltd | Other services | 2024 |
| News Agency Limited | Administrative & support | 2013 |
| Newsage Limited | Administrative & support | 2000 |
| Newzoids Two Limited | Information & communication | 2016 |
| Nexbridge Consulting Ltd | Information & communication | 2024 |
| Next Step Holding Limited | Administrative & support | 2016 |
| Nexus Fashion Limited | Wholesale & retail | 2020 |
| Nexus Homes Ltd | Real estate | 2023 |
| Nexus Software Ltd | Information & communication | 2015 |
| NHR Construction Limited | Construction | 2025 |
| NIA Impact Consult Ltd | Professional & scientific | 2022 |
| Niccorsair Limited | Wholesale & retail | 2025 |
| Nicenstripy Gardencare Limited | Administrative & support | 2008 |
| Nicenstripy Holdings Limited | Professional & scientific | 2008 |
| Nick Saunders Limited | Professional & scientific | 2011 |
| Nick Sedgwick Consulting Ltd | Information & communication | 2024 |
| Nick Swettenham Enterprises Ltd | Wholesale & retail | 2021 |
| Nicola Kiess Communications Limited | Professional & scientific | 2025 |
| Nicoletti Ltd | Information & communication | 2023 |