| New Dakshin Limited | Hospitality | 2023 |
| New Wonder Management Limited | Administrative & support | 2014 |
| New-Gen Building Ltd | Construction | 2026 |
| Newark and Sons Limited | Construction | 2003 |
| Newborn Properties Limited | Real estate | 2017 |
| Newcastle Building Solutions Ltd | Construction | 2025 |
| Newmarket Holidays Limited | Administrative & support | 1988 |
| Newmarket Promotions Limited | Administrative & support | 1983 |
| Newmarket Transport Limited | Transport & logistics | 1995 |
| Newton and Steven Limited | Transport & logistics | 2017 |
| Nexgen Builders Limited | Construction | 2025 |
| Next Level Access Limited | Construction | 2024 |
| Next Level Group Ltd | Information & communication | 2022 |
| Next Tyre Hub Ltd | Wholesale & retail | 2022 |
| Nextgen Science & Tech Ltd | Professional & scientific | 2024 |
| Nextol Ltd | Information & communication | 2022 |
| Nexus Leads Services Ltd | Professional & scientific | 2023 |
| NFS Tech Limited | Information & communication | 2024 |
| NFS Wellbeing Limited | Wholesale & retail | 2020 |
| NG Facilities Management Services Ltd. | Administrative & support | 2017 |
| Ngedits Ltd | Information & communication | 2020 |
| Nick Crew Film Services Limited | Information & communication | 2014 |
| Nick Finlow Ltd | Administrative & support | 2023 |
| Nicky Moore Haulage Ltd | Transport & logistics | 2013 |
| NICOLE10 Limited | Construction | 2011 |
| Nigel Curtis Associates Limited | Professional & scientific | 1986 |
| Niki Winterson Ltd | Arts & recreation | 2010 |
| Nilave Productions Ltd | Information & communication | 2024 |
| Nimrod Services Europe Limited | Administrative & support | 2014 |
| Nippur OIL Ltd | Mining & quarrying | 2024 |
| Nirvana Vape Chipstead Ltd | Wholesale & retail | 2025 |
| Nirvana Vape Holdings Limited | Financial services | 2024 |
| Nirvana Vape Ltd | Wholesale & retail | 2017 |
| Nishtha Arya Ltd | Health & social care | 2012 |
| Nishu Ltd | Wholesale & retail | 2018 |
| Nishy Ltd | Health & social care | 2024 |
| NJ Studio Ltd | Arts & recreation | 2026 |
| NK Home Renovation Ltd | Construction | 2022 |
| Nlite Tech Limited | Information & communication | 2020 |
| NMJ Healthcare Services Ltd | Health & social care | 2021 |
| NMN Eelavan Tech Limited | Information & communication | 2018 |
| NN Entertainment Ltd | Information & communication | 2019 |
| NNW Studio Ltd | Professional & scientific | 2024 |
| NO 1 Property Solution Ltd | Real estate | 2020 |
| NO Idea Growth Ltd | Professional & scientific | 2025 |
| Noah's ARK Media Ltd | Professional & scientific | 2017 |
| Nobil Homes Ltd | Construction | 2016 |
| Noctis SLP Limited | Wholesale & retail | 2025 |
| Nodecloud Ltd | Information & communication | 2023 |
| Noknoc Ltd | Information & communication | 2025 |
| Nomopal Ltd | Hospitality | 2026 |
| Nookcasa Limited | Real estate | 2023 |
| Norbrand Ltd | Wholesale & retail | 2025 |
| Nordic Apartments Parking Company Limited | Households | 2007 |
| Norfolk Gold Ltd | Agriculture & fishing | 2018 |
| Norseerin Properties Limited | Real estate | 2021 |
| North Downs Builders Limited | Construction | 2023 |
| North Star Care Group Ltd | Health & social care | 2026 |
| Northcliff Wealth Management Limited | Professional & scientific | 2020 |
| Northen Star Investment Ltd | Real estate | 2025 |
| Northern Van Lines Ltd | Transport & logistics | 2018 |
| Nova Beauty and Aesthetics Ltd | Other services | 2023 |
| Novafusion Limited | Professional & scientific | 2023 |
| Novera Consulting Ltd | Professional & scientific | 2026 |
| Novodax Ltd | Information & communication | 2024 |
| Nprop Ltd | Real estate | 2019 |
| NQF Ltd | Hospitality | 2021 |
| NR Nandha Constructions Ltd | Construction | 2018 |
| NRB Rentals Ltd | Real estate | 2025 |
| NRM Acting Ltd | Arts & recreation | 2015 |
| NRM Acting Property Ltd | Real estate | 2024 |
| Nsebett Enterprises Ltd | Health & social care | 2013 |
| NTL Invest Ltd | Real estate | 2022 |
| Ntsk Properties Ltd | Real estate | 2022 |
| Nuahlaymorris Limited | Health & social care | 2014 |
| Numani Goods Ltd | Wholesale & retail | 2024 |
| Nurturetek Ltd | Information & communication | 2019 |
| Nutaki Ltd | Financial services | 2010 |
| Nutz Media Ltd | Professional & scientific | 2023 |
| NVP Consultants Limited | Professional & scientific | 2026 |
| NWJ Autocare Ltd | Wholesale & retail | 2013 |
| NWS Music Ltd | Arts & recreation | 2024 |
| Nyika Digital Ltd | Professional & scientific | 2024 |
| Nysa Limited | Real estate | 2018 |
| O&E Medical Ltd | Professional & scientific | 2015 |
| O'Boyle & Co Limited | Construction | 2018 |
| O'Hways Ltd | Information & communication | 2010 |
| O'Neill Accountancy Solutions Limited | Professional & scientific | 2011 |
| Oak Projects (Wallington) Ltd | Construction | 2019 |
| Oakbridge House Limited | Households | 2024 |
| Oakfield International Ltd | Financial services | 2018 |
| Oakhurst Construction London Ltd | Construction | 2015 |
| Oakle Beauty Limited | Wholesale & retail | 2024 |
| Oakwood Services & Management Limited | Real estate | 2010 |
| Octav Construction Ltd | Construction | 2015 |
| Odat Financial Limited | Financial services | 2017 |
| Odpflexi Ltd | Health & social care | 2022 |
| OFC UK Football Academy Ltd | Other services | 2023 |
| OJ International Co Ltd | Wholesale & retail | 2026 |
| OJE Ntene Ltd | Wholesale & retail | 2025 |