| MW Services (South) Ltd | Professional & scientific | 2023 |
| Mwai Group Ltd | Wholesale & retail | 2019 |
| MWP Air Conditioning Limited | Construction | 2024 |
| Mxai Health Limited | Health & social care | 2024 |
| My Little Warrior Child C.I.C. | Education | 2023 |
| My Property Development Find Ltd | Real estate | 2024 |
| My Spice BUS Limited | Real estate | 2025 |
| My Tinnie Limited | Manufacturing | 2026 |
| Myday Homes Ltd | Real estate | 2020 |
| Myfuture Investments Limited | Information & communication | 2025 |
| Mynco Ltd | Other services | 2015 |
| Myriad Colour Ltd | Manufacturing | 2022 |
| Mystic India Limited | Administrative & support | 2007 |
| Myts Holdings Limited | Real estate | 2026 |
| MZI Corporate Limited | Financial services | 2024 |
| N C Retail Group Ltd | Wholesale & retail | 2026 |
| N Campbell Developments Ltd | Construction | 2011 |
| N Living Limited | Construction | 2019 |
| N M K Roofing Limited | Administrative & support | 2017 |
| N R a Gibbs Limited | Financial services | 2023 |
| N Rose Interiors Limited | Construction | 2006 |
| N&P Prop Co Limited | Real estate | 2020 |
| N. Cunningham Limited | Information & communication | 1998 |
| N. Russell & Co Limited | Professional & scientific | 2004 |
| N.K.M. Fire Protection Limited | Construction | 1981 |
| N15 Capital Limited | Information & communication | 2024 |
| Nabrasa Limited | Hospitality | 2011 |
| Nail Number 2 Ltd | Other services | 2023 |
| Naked Apps Ltd | Information & communication | 2026 |
| Nakora Ltd | Manufacturing | 2025 |
| Namaste Developments Limited | Construction | 2019 |
| Namibian Sustainable Biodiversity Ltd | Financial services | 2022 |
| Nanny Mcphee Consulting Ltd | Professional & scientific | 2020 |
| Nanotech Energy Save Ltd | Wholesale & retail | 2021 |
| Nansen UK Ltd | Information & communication | 2023 |
| Naphtali Investment Ltd | Financial services | 2024 |
| Narod Publishing | Information & communication | 2021 |
| Nashes Finance Ltd | Financial services | 2021 |
| Nashes Publishing Ltd | Information & communication | 2025 |
| Nashes Rural Finance Ltd | Financial services | 2021 |
| Natasha Sullivan Ltd | Other services | 2017 |
| Nathanial Groves Ltd. | Manufacturing | 2013 |
| Native Self Ltd | Wholesale & retail | 2021 |
| Natter Ltd | Information & communication | 2022 |
| Nature Nurture Gardens Ltd | Administrative & support | 2020 |
| Nature Wellbeing Limited | Health & social care | 2025 |
| Navren Ltd | Administrative & support | 2025 |
| NB Cullens Ltd | Real estate | 2020 |
| NB Pool Services Limited | Other services | 2021 |
| NB23 Ltd | Arts & recreation | 2024 |
| NCL Limited | Wholesale & retail | 2011 |
| NDM (Aylesford) Limited | Wholesale & retail | 2017 |
| Neale Health Limited | Health & social care | 2025 |
| Neasden Land Company Limited(The) | Real estate | 1928 |
| Neckinger Holdings Limited | Professional & scientific | 2008 |
| Neil Daly Tuning & Maintenance Services Ltd | Manufacturing | 2026 |
| Nest Business Solutions Ltd | Professional & scientific | 2026 |
| Nestwell Housing Ltd | Real estate | 2026 |
| NET an Estate Ltd | Real estate | 2020 |
| Netaplex Labs Limited | Professional & scientific | 2016 |
| Netistix Ltd | Information & communication | 2023 |
| Netsterling Solutions Limited | Information & communication | 2006 |
| Network Computing Limited | Information & communication | 1993 |
| Neunelfer Ltd | Wholesale & retail | 2020 |
| Neuro Horizons Ltd | Health & social care | 2023 |
| Neuro Physio Kent Ltd | Health & social care | 2012 |
| Neuro Rehabilitation Kent Ltd | Health & social care | 2018 |
| Neurotherapy Partnership LLP | | 2014 |
| Neves Prestige Storage Ltd | Transport & logistics | 2025 |
| New Flamboyant LP | | 2016 |
| New Hall Hotel Limited | Hospitality | 2007 |
| New Insights Therapy Limited | Health & social care | 2026 |
| New Leaf Investco Limited | Real estate | 2020 |
| New Wave Innovations Ltd | Wholesale & retail | 2025 |
| Newchain Limited | Extraterritorial | 1992 |
| Newhaven Asset Management Limited | Other services | 2011 |
| Newlands Joinery Ltd | Manufacturing | 2011 |
| Newlands Joinery UK Ltd | Manufacturing | 2015 |
| Newpsochem UK Limited | Wholesale & retail | 2021 |
| Newsure Group Limited | Financial services | 2010 |
| Newton Rachel Limited | Manufacturing | 2013 |
| Next GEN Academy Ltd | Education | 2017 |
| Nextgen Gymnastics Academy Ltd | Education | 2026 |
| Nextgen Research Limited | Information & communication | 2019 |
| Nextgen Sevenoaks District Ltd | Arts & recreation | 2026 |
| Nexus 4 Management Ltd | Construction | 2025 |
| Nexxium Ltd | Professional & scientific | 2025 |
| NH Wealth Ltd | Financial services | 2023 |
| NHP London Limited | Health & social care | 2019 |
| Nice International Partnership LP | | 2017 |
| Nice World Mortgages Limited | Other services | 2006 |
| Nicholas Dimpsey Ltd | Other services | 2023 |
| Nicholas Foreman Ltd | Other services | 2014 |
| Nicholls & Pearce (Waste Paper) Limited | Water & waste | 1961 |
| Nick Burgess Limited | Financial services | 2017 |
| Nick Frost Consulting Limited | Information & communication | 2016 |
| Nico Office Limited | Wholesale & retail | 2001 |
| Nicola Tarry Ballet International Ltd | Education | 2026 |
| Nigel Stapley Limited | Administrative & support | 2025 |
| Nikolato Limited | Wholesale & retail | 2026 |