| N & KAY Investments Limited | Real estate | 2024 |
| N Chill Limited | Manufacturing | 2017 |
| N Crisp Property Ltd | Real estate | 2025 |
| N G Sign Installations Ltd | Professional & scientific | 2019 |
| N Greenaway Construction Services Limited | Professional & scientific | 2011 |
| N J Dean & Co Limited | Wholesale & retail | 2013 |
| N J T Creative Limited | Arts & recreation | 2014 |
| N Johnson Limited | Real estate | 2020 |
| N Jones Construction Recruitment Ltd | Other services | 2024 |
| N&E Buildings Limited | Households | 2023 |
| N. J. M. (Swindon) Ltd | Information & communication | 1995 |
| N.L.I. Limited | Administrative & support | 2007 |
| N.Perrett Farriery Ltd | Agriculture & fishing | 2018 |
| N1 Digital Media Consulting Ltd | Information & communication | 2015 |
| N2 IT Solutions Limited | Information & communication | 2017 |
| Naass Real Estate & Co Limited | Real estate | 2021 |
| Nacsafe Ltd | Construction | 2013 |
| Nadala Transport Limited | Transport & logistics | 2025 |
| Nadia Grigore Ltd | Health & social care | 2019 |
| Nafruit Nafuti Ltd | Transport & logistics | 2024 |
| Nagera Ltd | Construction | 2015 |
| Nagle Enterprises Limited | Manufacturing | 2015 |
| Najah Tech Ltd | Professional & scientific | 2026 |
| Nalgo Sports and Leisure Limited | Education | 2019 |
| Nalgo Sports Club Ltd | Arts & recreation | 2022 |
| NAM & Partners Ltd | Financial services | 2014 |
| Namair Light Aircraft Maintenance Limited | Manufacturing | 2015 |
| Nancy's Hope Ltd | Health & social care | 2017 |
| Nandes Hair and Beauty Ltd | Other services | 2017 |
| Nank Property Investment Limited | Real estate | 2024 |
| Nano FIT2 Drive Ltd | Health & social care | 2025 |
| Nanogreen Cleaning Limited | Households | 2014 |
| Nanolux Coatings Limited | Administrative & support | 2025 |
| Napoleonic Ventures Ltd | Wholesale & retail | 2020 |
| NAR Carpentry Limited | Manufacturing | 2017 |
| Narrow Boat Heater Services Ltd | Manufacturing | 2026 |
| Nassif Ltd | Health & social care | 2023 |
| NAT BZ Management Ltd | Professional & scientific | 2022 |
| Natalie Wells Recruitment Ltd | Administrative & support | 2017 |
| Natasha Hunt Aesthetics Ltd | Other services | 2022 |
| Nate Holdings Limited | Real estate | 2025 |
| Nathan Glynn Jones Electrical Limited | Construction | 2018 |
| Nathan Hunt Cars Ltd | Wholesale & retail | 2016 |
| Nathan Hunt Mechanical Limited | Wholesale & retail | 2022 |
| Nathan Sparrow Limited | Professional & scientific | 2012 |
| Nathe Plumbing & Property Services Ltd | Construction | 2025 |
| Natiecare Limited | Health & social care | 2022 |
| National Bullying Helpline CIC | Administrative & support | 2024 |
| National Trust (Enterprises) Limited (the) | Wholesale & retail | 1972 |
| National Trust (Renewable Energy) Limited | Energy | 2013 |
| National Van Sales Ltd | Wholesale & retail | 2025 |
| National Vehicle Suppliers Ltd | Wholesale & retail | 2017 |
| Nationwide Covered Bonds LLP | | 2005 |
| Nationwide Healthcare Trustee Limited | Administrative & support | 2006 |
| Nationwide Home Loans Limited | Financial services | 1986 |
| Nationwide Housing Trust Limited | Financial services | 1987 |
| Nationwide Pension Fund Nominee Limited | Financial services | 2007 |
| Nationwide Pension Fund Trustee Limited | Financial services | 2007 |
| Nationwide Property Lettings Limited | Real estate | 2007 |
| Nationwide Syndications Limited | Financial services | 1990 |
| Nationwide Trust Limited | Financial services | 1972 |
| Nationwide Vehicle Sales Ltd | Wholesale & retail | 2026 |
| Naturacasa Ltd | Wholesale & retail | 2025 |
| Natural Capital (Land & Water) Limited | Professional & scientific | 2025 |
| Natural Healthcare (UK) Limited | Other services | 2014 |
| Natural Selection Salon Ltd | Other services | 2023 |
| Natural Senses Limited | Wholesale & retail | 2014 |
| Naturalpathtohealing Limited | Health & social care | 2025 |
| Nature's Warehouse Ltd | Wholesale & retail | 2016 |
| Naturopathic Nutrition Association Ltd | Other services | 2015 |
| Naunton Downs Debentures Limited | Real estate | 1993 |
| Navabrind IT Solutions PVT Limited | Information & communication | 2021 |
| Naval & Military Bible Society Ltd | Information & communication | 2004 |
| Naventus Limited | Construction | 2015 |
| Navotech Solutions Limited | Professional & scientific | 2023 |
| Navriolan Limited | Professional & scientific | 2016 |
| NAZ IT Solutions Ltd | Professional & scientific | 2018 |
| NB Holdco Limited | Financial services | 2020 |
| NBC Properties Limited | Real estate | 2013 |
| Nbdy Ltd | Information & communication | 2024 |
| Nbino & Co Limited | Real estate | 2024 |
| Nbjork Ltd | Health & social care | 2018 |
| NBK Box Limited | Wholesale & retail | 2025 |
| NBK Convenience Store Ltd | Wholesale & retail | 2022 |
| NBK Oral Solutions Limited | Health & social care | 2017 |
| NBK Properties Ltd | Real estate | 2020 |
| NBP Estates Limited | Real estate | 2008 |
| NBS Cosec Limited | Professional & scientific | 2019 |
| NBS Ventures Limited | Financial services | 2018 |
| NBS Ventures Management Limited | Financial services | 2018 |
| NBT Trading Limited | Hospitality | 2005 |
| NC Farming Limited | Agriculture & fishing | 2009 |
| NCL Logistic Ltd | Transport & logistics | 2023 |
| Nclwf Limited | Professional & scientific | 2013 |
| NCS Education Services Ltd | Education | 2023 |
| NDA Developments Limited | Real estate | 2008 |
| NDH Investments Limited | Real estate | 2025 |
| NDH Landscaping Ltd | Construction | 2009 |
| Ndluv Ltd | Health & social care | 2024 |
| NDM Properties Limited | Real estate | 2003 |