| New Pier Capital Finance Limited | Other services | 2013 |
| New Turbulence Media Ltd | Information & communication | 2023 |
| New Zealand Avenue Properties 29, 31, 33 & 35 Ltd | Real estate | 2001 |
| Newacc (2018) Limited | Other services | 2018 |
| Newacc Trustee Limited | Financial services | 2024 |
| Newlands Investments | Financial services | 2014 |
| Newlyn RTM Company Limited | Households | 2019 |
| Newship Developments Limited | Construction | 2021 |
| Newship Distribution Limited | Professional & scientific | 1978 |
| Newship Group Limited | Professional & scientific | 1978 |
| Newship Healthcare Administration Limited | Administrative & support | 2024 |
| Newship Industries Limited | Professional & scientific | 1938 |
| Newship Investments Limited | Professional & scientific | 1959 |
| Newship Limited | Professional & scientific | 2001 |
| Newship Manufacturing Limited | Real estate | 1988 |
| Newship Products Group Limited | Professional & scientific | 1977 |
| Newship Products Limited | Professional & scientific | 1986 |
| Newship Properties Limited | Financial services | 2021 |
| Newwaves Solutions Limited | Construction | 1970 |
| Nexivita Ltd | Administrative & support | 2026 |
| Next Door Tutor Ltd | Education | 2023 |
| Nextapex Ltd | Information & communication | 2026 |
| Nextgenx Solutions Limited | Information & communication | 2025 |
| Nexwan Global Ltd | Information & communication | 2023 |
| NGS Partners Limited | Real estate | 2022 |
| NIB Advisors Ltd | Administrative & support | 2021 |
| Nicc Standards Limited | Information & communication | 2008 |
| Nicholfilms Limited | Administrative & support | 2011 |
| Nicholls Construction Limited | Construction | 2021 |
| Nick Angel Limited | Information & communication | 2009 |
| Nick SK Properties Ltd | Real estate | 2026 |
| Nick Spalding Limited | Information & communication | 2015 |
| Nicola SIX Limited | Administrative & support | 2013 |
| Niger Creek Energy Ltd | Other services | 2013 |
| Nikka Investments Ltd | Financial services | 2022 |
| Nikki's Caffe Limited | Hospitality | 2013 |
| Nimascott Limited | Administrative & support | 2023 |
| Nina Pictures UK Limited | Information & communication | 2024 |
| Ninalife Ltd | Health & social care | 2025 |
| Ninarof Ltd | Information & communication | 2024 |
| Nine Leathwaite Road Limited | Households | 2005 |
| Nixie London Limited | Extraterritorial | 2017 |
| NJK Group Limited | Financial services | 2025 |
| NJO Investments Limited | Real estate | 2021 |
| Nksc Property Ltd | Real estate | 2026 |
| Nmcc Partners Ltd | Information & communication | 2025 |
| Nmzm Holdings Ltd | Real estate | 2024 |
| NO Reservations Entertainment Limited | Arts & recreation | 2012 |
| NO5 Weybridge Ltd | Hospitality | 2025 |
| Nobody in Limited | Hospitality | 2014 |
| Noel Roscoe Limited | | 1956 |
| Noir Prive Group Ltd | Arts & recreation | 2025 |
| Noms Financial Solutions Ltd | Financial services | 2017 |
| Noosa QLD Limited | Real estate | 2025 |
| Nora Sports Consulting Limited | Professional & scientific | 2022 |
| Noriyoshi Horiuchi Ltd | Administrative & support | 2007 |
| North West Limited | Professional & scientific | 2016 |
| Northcote Management Co. Limited | Households | 1992 |
| Notlezah Enterprises Ltd | Real estate | 2013 |
| Notting Hill Lofts Management Ltd | Households | 2019 |
| Nourishful Nutrition Ltd | Health & social care | 2023 |
| Nova AI Creative Limited | Information & communication | 2025 |
| Novus Finitor (UK) Limited | Administrative & support | 2011 |
| Noyatech Digital Technologies Limited | Wholesale & retail | 2026 |
| NRH Autoworks Limited | Other services | 2016 |
| NS Investments One (UK) Limited | Mining & quarrying | 2022 |
| NTA Fashion (UK) Limited | Financial services | 2022 |
| NTA PVT. Limited | Wholesale & retail | 2024 |
| NTH Degree Consultancy Ltd | Extraterritorial | 2017 |
| NU Currencies Limited | Financial services | 2011 |
| Nuestra Vida Ltd. | Construction | 2018 |
| Nuland Design Limited | Professional & scientific | 2024 |
| Numan Music Limited | Professional & scientific | 1979 |
| Number 10 Financial Services Limited | Financial services | 2015 |
| Number One Portsmouth LLP | | 2011 |
| Numera Finance Limited | Professional & scientific | 2024 |
| Numina Media Group Limited | Information & communication | 2017 |
| Nutfield Court Management Company (Bromley) Limited | Households | 2011 |
| Nwev Services Ltd | Professional & scientific | 2010 |
| NWP Consulting Limited | Real estate | 2017 |
| NXI Group Limited | Information & communication | 2025 |
| NZ Build Ltd | Construction | 2010 |
| Nzero Ltd. | Information & communication | 2021 |
| O Roberts Garden & Tree Services Limited | Administrative & support | 2017 |
| O'Sullivan Investment Holdings Ltd | Financial services | 2025 |
| O.K.B. Consulting Limited | Other services | 2014 |
| Oak Croft Homes (Surrey) LLP | | 2024 |
| Oak Croft Land & Developments Limited | Real estate | 2023 |
| Oakcroft Property Group Ltd | Construction | 2020 |
| Oakdene Court Residents Company Limited | Real estate | 2003 |
| Oakhill Construction S.E Limited | Construction | 2011 |
| Oakhill Europe Limited | Other services | 2011 |
| Oakley Residential Management Ltd | Real estate | 2026 |
| Oakwey Construction Ltd | Construction | 2010 |
| Oakwood Avenue Residents Company Limited | Households | 1992 |
| Oatlands (MSH) Ltd | Financial services | 2024 |
| Oatlands Close Limited | Real estate | 2009 |
| Oatlands Drive (Village Close) Residents Association Limited | Households | 1985 |
| Oatlands Green Residents Society Limited(The) | Households | 1967 |
| Oatlands Investments Limited | Hospitality | 1986 |