| Naxos Audio Books (UK) Limited | Information & communication | 2005 |
| Naxos Music UK Limited | Wholesale & retail | 1991 |
| Naxos Rights (Europe) Ltd | Information & communication | 2016 |
| Nazcorp Ltd | Administrative & support | 2020 |
| NBJ Group Limited | Extraterritorial | 2007 |
| Neil Walston Consulting Ltd | Information & communication | 2023 |
| Neml Ltd | Hospitality | 2021 |
| NEO Opsis Ltd | Information & communication | 2025 |
| Neolabai Ltd | Information & communication | 2025 |
| Neon Nihon Ltd | Wholesale & retail | 2026 |
| Neovenator Ltd | Professional & scientific | 1997 |
| Nera Satellite Services Limited | Extraterritorial | 2010 |
| Netherleigh Park Management Limited | Households | 1964 |
| Nets International Limited | Information & communication | 2020 |
| Neuro-Xi Ltd | Information & communication | 2025 |
| Neva Assets LLP | | 2006 |
| Neva House (Piltdown) Limited | Households | 2022 |
| New Future People Limited | Information & communication | 2010 |
| New GS Properties Limited | Real estate | 2019 |
| New Leaf Zero Waste Ltd | Wholesale & retail | 2020 |
| New Tangent Limited | Professional & scientific | 2013 |
| Newrose Property Limited | Construction | 2016 |
| Newvoiceuk Ltd | Professional & scientific | 2019 |
| NEX GEN Business Ltd | Information & communication | 2005 |
| Nexai Advisory Limited | Information & communication | 2025 |
| Nexeus Enterprise Ltd | Information & communication | 2012 |
| Nexolla Ltd | Wholesale & retail | 2025 |
| Next CUE Ltd | Arts & recreation | 2022 |
| Next Generation Innovation Recruitment Services Ltd | Administrative & support | 2022 |
| Next Level Services Group Ltd | Administrative & support | 2022 |
| Next Phase Coffee Ltd | Manufacturing | 2023 |
| Ngage Media Ltd | Information & communication | 2019 |
| NHI Trading Limited | Wholesale & retail | 2015 |
| NIA Lifts Ltd | Construction | 2016 |
| Nicci Long OT Services Ltd | Health & social care | 2006 |
| Nick Cronin Creative Limited | Professional & scientific | 2016 |
| Nicola Brownjohn Safeguarding Consultancy Limited | Professional & scientific | 2019 |
| Niconico Ltd | Professional & scientific | 2021 |
| Nigel Cook Consulting Ltd | Administrative & support | 2020 |
| Nikki Franklin Music Ltd | Arts & recreation | 2021 |
| Nile Investment London Ltd | Financial services | 2025 |
| Nimaa Ltd | Health & social care | 2022 |
| Nimadol Spice Limited | Hospitality | 2025 |
| Nimbus Homes Limited | Construction | 2014 |
| Nisha & Bhavan Ltd | Real estate | 2022 |
| NJ Solar Limited | Construction | 2023 |
| NJR Holdings Limited | Other services | 2017 |
| NO Boundaries Garden Design Ltd | Professional & scientific | 2016 |
| NOA Toys and Games Ltd | Wholesale & retail | 2023 |
| Noam Beer Limited | Wholesale & retail | 2024 |
| Nobogram Restaurant Ltd | Hospitality | 2018 |
| Nodal Properties Limited | Hospitality | 2026 |
| NOG Holdings Limited | Professional & scientific | 2007 |
| Nolari Ltd | Wholesale & retail | 2019 |
| Nonpareil Consulting Limited | Professional & scientific | 2025 |
| Noorel Limited | Health & social care | 2025 |
| Nopheros Investments Ltd | Real estate | 2019 |
| Norkway 2024 Ltd | Construction | 2024 |
| Norman Brickwork Limited | Construction | 1989 |
| Norman Family Holdings Limited | Extraterritorial | 2010 |
| Norman Scaffolding Limited | Extraterritorial | 2013 |
| North END PFC Ltd | Hospitality | 2026 |
| North Star FX Ltd | Education | 2021 |
| Nova World Ltd | Administrative & support | 2017 |
| Novadex Limited | Information & communication | 2026 |
| Novo Praxis Limited | Real estate | 2014 |
| Novus (Kent) Ltd | Transport & logistics | 2021 |
| NSJ Trading Limited | Wholesale & retail | 2009 |
| Nssl Limited | Extraterritorial | 1996 |
| Nsslglobal Limited | Information & communication | 1999 |
| Nssman Limited | Information & communication | 2010 |
| NT Membership Solutions Limited | Other services | 2024 |
| Ntip Limited | Professional & scientific | 2009 |
| Ntlfuturegroup Ltd | Wholesale & retail | 2020 |
| Ntrust Systems Limited | Information & communication | 2002 |
| NU Essence Limited | Wholesale & retail | 2013 |
| Nuex Holdings Limited | Professional & scientific | 2009 |
| Numberland Limited | Information & communication | 2017 |
| Nurture Durham Limited | Education | 2020 |
| Nurture&Nest Surrey Ltd | Real estate | 2025 |
| NUS Consulting Group Limited | Information & communication | 1965 |
| Nutel Energy Limited | Information & communication | 2001 |
| Nutfield Centre Ltd | Construction | 1967 |
| Nutfield Cross Consultancy Limited | Professional & scientific | 2018 |
| Nutfield Vineyard Limited | Agriculture & fishing | 2023 |
| Nutfield Wellbeing Limited | Other services | 2022 |
| Nutraceuticals Group Europe Ltd | Administrative & support | 2013 |
| Nutrigrain Delights Ltd | Hospitality | 2026 |
| NV Driveways & Landscaping Ltd | Construction | 2020 |
| NV Elite Performance Ltd | Arts & recreation | 2022 |
| NVH Global Limited | Manufacturing | 2013 |
| Nvsge Studios Limited | Manufacturing | 2019 |
| NW Management Consultancy Limited | Professional & scientific | 2006 |
| NWI Services Ltd | Professional & scientific | 2024 |
| Nzyuko Limited | Health & social care | 2022 |
| O'Doyle's Speed Shop Ltd | Wholesale & retail | 2023 |
| Oa-Uk Ltd | Professional & scientific | 2023 |
| Oak Fire & Security Ltd | Construction | 2022 |
| Oak Lodge (Norwood) Residents Association Limited | Households | 1971 |
| Oakborough Limited | Real estate | 1998 |