| N23 Construction Limited | Households | 2022 |
| N24 Construction Limited | Households | 2022 |
| N25 Construction Limited | Households | 2022 |
| N77 Property Investment Ltd. | Real estate | 2024 |
| Nadall Consulting Ltd | Administrative & support | 2017 |
| Nadnev Limited | Construction | 2019 |
| Nadnev Properties Ltd | Real estate | 2023 |
| Nairn Court RTM Company Ltd | Households | 2012 |
| Naise Limited | Information & communication | 2012 |
| NAJEEB46 Ltd | Financial services | 2025 |
| Najo Development Limited | Real estate | 2018 |
| Namco Power Solutions Ltd | Professional & scientific | 2025 |
| Namcod Limited | Other services | 2019 |
| Namdy’S African Restaurant & Bar Ltd | Hospitality | 2025 |
| Nanachiaa Limited | Construction | 2018 |
| Nanatec Ltd | Information & communication | 2023 |
| Nanhurst Management Company Limited | Households | 1998 |
| Nanya Ltd | Real estate | 2022 |
| Narugute Limited | Health & social care | 2021 |
| Nasip Natural Ltd | Wholesale & retail | 2025 |
| Nasiya Ltd | Wholesale & retail | 2020 |
| NAT & Steph Consultancy Limited | Information & communication | 2014 |
| Natalia Best Construction Ltd | Construction | 2024 |
| Natezoe Health Ltd | Health & social care | 2026 |
| Nationwidehub Limited | Administrative & support | 2022 |
| Nativis International Ltd | Wholesale & retail | 2020 |
| Natur Fields Ltd | Manufacturing | 2020 |
| Naturt Ltd | Wholesale & retail | 2025 |
| Navu Investment Limited | Wholesale & retail | 2025 |
| Nazara Co Limited | Other services | 2025 |
| NB & WJ Holdings Limited | Financial services | 2015 |
| NB Painting Ltd | Construction | 2015 |
| NC London Joinery Ltd | Construction | 2023 |
| NC Security Training Service Ltd | Education | 2025 |
| NCF Elites Ltd | Administrative & support | 2019 |
| NCF London Elites Ltd | Administrative & support | 2017 |
| ND Lens Limited | Information & communication | 2024 |
| ND Medical Services Limited | Health & social care | 2023 |
| ND Surveying Ltd | Professional & scientific | 2020 |
| NDN Telecoms Ltd | Construction | 2022 |
| Ndoona Health Staffing Limited | Public administration | 2025 |
| NDS Heating Limited | Construction | 2024 |
| NE Consulting London Ltd | Professional & scientific | 2026 |
| NE Decorators Ltd | Construction | 2025 |
| Neals Amusements and Event Hire Ltd | Arts & recreation | 2022 |
| Neamarius Transport Ltd | Transport & logistics | 2021 |
| NEC Healthcare Services Ltd | Health & social care | 2022 |
| NED Dwellings Limited | Real estate | 2023 |
| Nedelcu Trans Ltd | Transport & logistics | 2016 |
| Nedlaworks Ltd | Information & communication | 2025 |
| NEE Plant & Groundworks Ltd | Agriculture & fishing | 2019 |
| Need One Group Ltd | Professional & scientific | 2018 |
| Need One Ltd | Education | 2014 |
| Need One Recruitment Ltd | Administrative & support | 2020 |
| Needs Limited | Manufacturing | 1959 |
| Needs Plastics Limited | Extraterritorial | 2010 |
| Neeks Ltd | Health & social care | 2019 |
| Neesak Clean Co. Ltd | Administrative & support | 2026 |
| NEF Business Ltd | Wholesale & retail | 2018 |
| Neha Property Ltd | Real estate | 2023 |
| Neks Health Limited | Health & social care | 2023 |
| Nelo Property Management Ltd | Real estate | 2023 |
| Nenerose Group Ltd | Administrative & support | 2025 |
| Neolith UK Limited | Wholesale & retail | 2017 |
| Neonbee Ltd | Manufacturing | 2017 |
| Nephrite Properties Limited | Households | 1987 |
| Nest Sanctuary Limited | Health & social care | 2023 |
| Nestfolk Ltd | Arts & recreation | 2024 |
| NET Academies Trust | Education | 2012 |
| NET S Engineers Ltd | Administrative & support | 2016 |
| Net-Com (92) Limited | Construction | 1992 |
| Netplast Ltd | Construction | 2023 |
| Nett PAR Ltd | Wholesale & retail | 2026 |
| Netteswell Pharma Ltd | Health & social care | 2019 |
| Netuada Ltd | Health & social care | 2015 |
| Network Hygiene Limited | Administrative & support | 2011 |
| Network Support Engineers Limited | Administrative & support | 2012 |
| Networx Maintenance Ltd | Professional & scientific | 2026 |
| Neurahub Ltd | Information & communication | 2026 |
| Neuroalchemy Limited | Health & social care | 2025 |
| Neurocheck Health Ltd | Health & social care | 2024 |
| Nevill Construction Ltd | Manufacturing | 2026 |
| Neville House RTM Company Limited | Households | 2011 |
| Nevin London Limited | Wholesale & retail | 2025 |
| New AGE Cleaning Services Ltd | Health & social care | 2024 |
| New Barns CLB Limited | Extraterritorial | 2023 |
| New Britannia Transport Limited | Transport & logistics | 2024 |
| New ERA TEX and Property Limited | Real estate | 2024 |
| New Generation Top Services Ltd | Administrative & support | 2018 |
| New Green Place Residents Company Limited | Households | 1997 |
| New Ground Cafe Ltd | Hospitality | 2020 |
| New Homes Carpeting Limited | Administrative & support | 2002 |
| New Life Care Homes Ltd | Health & social care | 2026 |
| New Line Interiors Limited | Construction | 2017 |
| New Metals and Chemicals (Holdings) Limited | Professional & scientific | 1944 |
| New Metals and Chemicals Limited | Wholesale & retail | 2015 |
| New Steps Nursery Limited | Health & social care | 2017 |
| New Town Taxis Limited | Transport & logistics | 2025 |
| New Vision Construction S.E Ltd | Manufacturing | 2023 |
| New Vision Projects Ltd | Construction | 2026 |