| Nezbuild Estate Ltd | Real estate | 2020 |
| NF Group Holdings Limited | Financial services | 2025 |
| NFS Screeding Ltd | Construction | 2014 |
| Ngala Limited | Other services | 2007 |
| Ngnv Ltd | Public administration | 2023 |
| Ngorringe Limited | Information & communication | 2010 |
| NGP Next Generation Programs Ltd | Professional & scientific | 2023 |
| NH the Window Cleaners Ltd | Administrative & support | 2024 |
| NHU Developments Limited | Construction | 2019 |
| NHU Group Investments Limited | Real estate | 2020 |
| NHU Investment Limited | Construction | 2020 |
| Niall Mclaughlin Architects Ltd | Professional & scientific | 2016 |
| Nice-Av Ltd | Information & communication | 2025 |
| Nick Johnson TV Limited | Information & communication | 2016 |
| Nick Umney Architectural Limited | Administrative & support | 2013 |
| Nigeria Disability Assoc UK Ltd | Education | 2025 |
| Nigerians in Diaspora Organisation UK Chapter Limited | Construction | 2024 |
| Nightclub Stream Limited | Professional & scientific | 2019 |
| Nigsun Limited | Information & communication | 2016 |
| Nikita Party & Entertainment Ltd | Arts & recreation | 2023 |
| Nikki Holden Counselling Limited | Health & social care | 2023 |
| Nikkijay Games Ltd | Professional & scientific | 2024 |
| Nikott Limited | Construction | 2019 |
| Nindora Ltd | Wholesale & retail | 2025 |
| Ninelx Ltd | Wholesale & retail | 2025 |
| Niqaa Limited | Information & communication | 2026 |
| Nishan Logistics Limited | Transport & logistics | 2025 |
| Nissi Healthcare Services Limited | Public administration | 2021 |
| NJA Maintenance Ltd | Administrative & support | 2024 |
| NK Okwuosa Ltd | Wholesale & retail | 2026 |
| Nlfa Ltd | Extraterritorial | 2008 |
| Nlma Ltd | Extraterritorial | 2010 |
| NLX Health Limited | Health & social care | 2024 |
| Nmatic Group Ltd | Financial services | 2025 |
| Nmdigit Limited | Real estate | 2024 |
| NMF Marine Engineering Limited | Professional & scientific | 2008 |
| NNR Holdings Limited | Financial services | 2023 |
| NNR Investments Limited | Financial services | 2023 |
| Noble Taverns Limited | Administrative & support | 2009 |
| Nobull Fitness Limited | Arts & recreation | 2017 |
| Node Park Management Company Limited | Households | 2019 |
| NOK Group Ltd | Wholesale & retail | 2019 |
| Nokamed Ltd | Health & social care | 2023 |
| Nomi Homes LLP | | 2019 |
| Non-Aligned CIC | Education | 2024 |
| NOR One Ltd | Construction | 2024 |
| Nord Procurement Ltd | Wholesale & retail | 2022 |
| Nordic Catering Limited | Hospitality | 2016 |
| Norfolk Dream Limited | Real estate | 2025 |
| North Central Herts School of Dance Limited | Arts & recreation | 2025 |
| North Eastern Leisure Ltd | Hospitality | 2018 |
| North Herts Utilities Limited | Construction | 2013 |
| North London Electrical Contractors Ltd | Construction | 2018 |
| North of Mars Limited | Information & communication | 2021 |
| Northcaster Group Limited | Financial services | 2025 |
| Norton Green Car Centre Limited | Other services | 2017 |
| Norton Green Developments Limited | Construction | 2018 |
| Norwood Group Limited | Construction | 2016 |
| NOT Just Props Ltd | Arts & recreation | 2018 |
| NOT Just Transport Ltd | Transport & logistics | 2025 |
| Nova Computer Systems Ltd | Manufacturing | 2024 |
| Nova Glass Ltd | Construction | 2020 |
| Nova Wellness Studios Limited | Other services | 2025 |
| Novarise Property Ltd | Real estate | 2023 |
| Novas Digital Limited | Professional & scientific | 2024 |
| Novo Modo Limited | Professional & scientific | 2021 |
| Novon Healthcare Limited | Health & social care | 2025 |
| Novus Technologie Limited | Information & communication | 2019 |
| NOW That's What I Call Music Supervision 7 Ltd | Information & communication | 2023 |
| NP Modelling Limited | Professional & scientific | 2020 |
| Npaw Management Limited | Real estate | 2025 |
| NR Investment Management Ltd | Administrative & support | 2011 |
| NR Removals Ltd | Transport & logistics | 2024 |
| NRC Homes Ltd | Construction | 2025 |
| NRG Therapeutics Ltd | Professional & scientific | 2018 |
| NSC Films Ltd | Information & communication | 2022 |
| NSK Medical Services Limited | Health & social care | 2017 |
| NSK United Kingdom Limited | Manufacturing | 2007 |
| NTC Designs Ltd | Professional & scientific | 2014 |
| Ntfulini Healthcare Services Ltd | Health & social care | 2014 |
| NTI Audio UK Limited | Wholesale & retail | 2018 |
| NU ERA Estates Ltd | Real estate | 2020 |
| Nu-Line Decorating Services Ltd | Construction | 2022 |
| Nu-Line Domestic Decorating Services Ltd | Construction | 2025 |
| Nuable Group Limited | Administrative & support | 2024 |
| Nubian Essence Ltd | Wholesale & retail | 2025 |
| Nupafeed Limited | Wholesale & retail | 2006 |
| Nupafeed UK Limited | Wholesale & retail | 2006 |
| Nurband Ltd | Wholesale & retail | 2026 |
| Nursery Gardens (Welwyn) Freehold Company Limited | Real estate | 2006 |
| Nursery Gardens (Welwyn) Management Company Limited(The) | Real estate | 1979 |
| Nutrisoll Ltd | Administrative & support | 2025 |
| Nuts About Ltd | Wholesale & retail | 2022 |
| Nutwood Estates Limited | Professional & scientific | 2023 |
| Nutzu Limited | Transport & logistics | 2018 |
| Nyce Things Ltd | Wholesale & retail | 2022 |
| Nycolles Wood 2016 Management Company Limited | Households | 2016 |
| Nyneyaad Enterprise Ltd | Wholesale & retail | 2023 |
| NYY Nationwide Limited | Other services | 2018 |
| NYY Nationwide Management Ltd | Professional & scientific | 2023 |