| Nfklyndhurst Limited | Hospitality | 2024 |
| NFS Mediation Limited | Health & social care | 2011 |
| NFT Scaffolding Ltd | Construction | 2023 |
| NG Draughting Services Ltd | Professional & scientific | 2008 |
| Ng&Gg Ltd | Real estate | 2026 |
| NGK Wealth Management Ltd | Professional & scientific | 2020 |
| Ngkaren Ltd | Wholesale & retail | 2024 |
| NGL Limited | Extraterritorial | 1985 |
| Ngma Academy Ltd | Education | 2025 |
| Ngma Events Ltd | Wholesale & retail | 2025 |
| Ngma Grappling Ltd | Education | 2025 |
| Ngma MMA Ltd | Education | 2025 |
| NGS Construction & Estates Ltd | Construction | 2014 |
| NGS Enterprises & Trading Ltd | Construction | 2016 |
| NGS Global Services Ltd | Manufacturing | 2014 |
| NGS Gritting Services Ltd | Other services | 2014 |
| NGS Group Trading Ltd | Construction | 2016 |
| NGS Salt Supplies Ltd. | Administrative & support | 2014 |
| NGS Trading & Holdings Ltd | Real estate | 2016 |
| NH Aviation Ltd | Manufacturing | 2018 |
| NHK Health Ltd | Wholesale & retail | 2022 |
| NHM Properties Ltd | Real estate | 2025 |
| NI 7 Systems Limited | Health & social care | 1995 |
| NI Consultants Services Ltd | Wholesale & retail | 2017 |
| Niac Prodectile Limited | Construction | 2023 |
| Niamat Khail Limited | Wholesale & retail | 2025 |
| Nicara's Coffee Ltd | Wholesale & retail | 2012 |
| Nice Elephant Limited | Hospitality | 2023 |
| Nice Systems Technologies UK Limited | Information & communication | 1993 |
| Nice Systems UK Finance Limited | Administrative & support | 2010 |
| Nice Systems UK Limited | Information & communication | 1997 |
| Niche Holdings Limited | Extraterritorial | 1987 |
| Nicheland Ukeig | | 2010 |
| Nichita Logistics Ltd | Transport & logistics | 2025 |
| Nicholas Charles Limited | Professional & scientific | 2025 |
| Nicholas Property Services Ltd | Real estate | 2017 |
| Nici Hotels (Beachcroft) Limited | Real estate | 2024 |
| Nici Hotels (Bournemouth) Limited | Real estate | 2020 |
| Nici Hotels (Lymington) Limited | Hospitality | 2025 |
| Nici Hotels (Newquay) Limited | Real estate | 2024 |
| Nici Hotels Limited | Hospitality | 2017 |
| Nick Allan Building & Carpentry Ltd | Construction | 2015 |
| Nick Belson Design Limited | Information & communication | 1996 |
| Nick Hodge Associates Limited | Professional & scientific | 2014 |
| Nick Lambert Associates Limited | Professional & scientific | 2012 |
| Nick Little Photography Ltd | Professional & scientific | 2021 |
| Nick Real Estate Limited | Real estate | 2021 |
| Nickel Holdings Limited | Real estate | 2018 |
| Nicky Barfoot Ltd | Health & social care | 2013 |
| Nicolas Deliveries Ltd | Transport & logistics | 2025 |
| Nicolas James Building Limited | Construction | 2016 |
| Nicolas James Developments Limited | Professional & scientific | 2014 |
| Nicolas James Limited | Professional & scientific | 2015 |
| Nicolas James Residential Lettings Ltd. | Hospitality | 2007 |
| Nicolas James Studio Limited | Professional & scientific | 2025 |
| Nicolas James Trustee (NO.2) Limited | Financial services | 2007 |
| Nicoles Takeaway Ltd | Hospitality | 2024 |
| Nicubilder Ltd | Construction | 2023 |
| Niemirski Trans Ltd | Transport & logistics | 2021 |
| NIF Investments Limited | Wholesale & retail | 2022 |
| Night Exchange Limited | Extraterritorial | 1997 |
| Nightcub Ltd. | Information & communication | 2018 |
| Nightingale Court Management Limited | Households | 1987 |
| Nightingale Ground Care Ltd | Agriculture & fishing | 2006 |
| Nightingale Spice Ltd | Hospitality | 2023 |
| Nightlife Clubs Limited | Administrative & support | 2006 |
| Nihan Properties Limited | Real estate | 2020 |
| NIK Management Ltd | Extraterritorial | 2016 |
| NIK NAK Property Limited | Real estate | 2017 |
| Nikiforovas TM Ltd | Construction | 2024 |
| Nikki's Alterations Ltd | Extraterritorial | 2010 |
| Nillson Properties Ltd | Real estate | 2018 |
| Nils Taube Limited | Other services | 1994 |
| NIM Health & Beauty (Bedford Place) Limited | Other services | 2019 |
| NIM Health & Beauty (Botley) Limited | Other services | 2019 |
| NIM Health & Beauty (West END) Limited | Other services | 2019 |
| Nimble Data Ltd | Information & communication | 2025 |
| Nimi Properties Ltd | Real estate | 2021 |
| Nine & Nico Ltd | Professional & scientific | 2020 |
| Nine 5 Three Limited | Administrative & support | 2001 |
| Nine Hazelnuts Technology Ltd | Professional & scientific | 2009 |
| Nine Thirty Films Ltd | Information & communication | 2025 |
| Nine Worlds Apart Limited | Information & communication | 2025 |
| NINE23 Ltd | Information & communication | 2012 |
| Nineteen Seventy Limited | Other services | 2021 |
| Nineteenfortynine Ltd | Wholesale & retail | 2024 |
| Ninety Nine Touring Ltd | Construction | 2022 |
| Ninja Leisure UK Bristol Cribbs Ltd | Arts & recreation | 2021 |
| Ninja Leisure UK Leeds Ltd | Arts & recreation | 2020 |
| Ninja Leisure UK Liverpool Ltd | Arts & recreation | 2021 |
| Ninja Leisure UK Newcastle Limited | Arts & recreation | 2022 |
| Ninja Leisure UK Walsall Ltd | Arts & recreation | 2021 |
| Nipperdog Ltd | Construction | 2014 |
| Nipro Diagnostics (UK) Limited | Wholesale & retail | 2000 |
| Nipro Medical UK Ltd | Wholesale & retail | 2009 |
| Niquesa World Limited | Hospitality | 2012 |
| Niroo Limited | Real estate | 2024 |
| Nirvana House Ltd | Other services | 2025 |
| NIS Convenience Store Ltd | Wholesale & retail | 2014 |
| NIS Enterprise Limited | Information & communication | 2023 |