| Nisaranwar Ltd | Wholesale & retail | 2025 |
| Niskus Performance Ltd | Professional & scientific | 2025 |
| Nistin Ltd | Administrative & support | 2011 |
| Nixon Industrial Diamonds Limited | Manufacturing | 1968 |
| Nixxi Rose Limited | Other services | 2023 |
| NJ (Grays Dairy) Limited | Real estate | 2025 |
| NJ (Poole Road) Limited | Real estate | 2025 |
| NJ (Putney) Limited | Real estate | 2025 |
| NJ Investco 2 Limited | Financial services | 2020 |
| NJ Investco Limited | Financial services | 2020 |
| NJ Motors Group Ltd | Manufacturing | 2018 |
| NJ Propco Limited | Real estate | 2021 |
| NJ Window Cleaning Ltd | Administrative & support | 2022 |
| NJC Studio Ltd | Professional & scientific | 2026 |
| Njemrad Limited | Health & social care | 2024 |
| NJG Alexandra Wharf Limited | Real estate | 2013 |
| NJG Froyle Park Limited | Real estate | 2012 |
| NJG Froyle Park Properties (NO. 2) Limited | Real estate | 2017 |
| NJG International Developments Limited | Financial services | 2018 |
| NJG Investments Limited | Financial services | 2017 |
| NJK Limited | Professional & scientific | 1995 |
| NJM Material Handling & Logistics Limited | Manufacturing | 2024 |
| NJM Metal Recycling Limited | Water & waste | 2014 |
| NJM Systems Ltd | Construction | 2014 |
| NJM Vehicle Sales Limited | Wholesale & retail | 2022 |
| NJP Enterprise Limited | Wholesale & retail | 2006 |
| NK1 Property Ltd | Real estate | 2026 |
| Nkediscare Ltd | Health & social care | 2019 |
| NKL Stars Ltd | Real estate | 2020 |
| NKM Enterprise Limited | Wholesale & retail | 2020 |
| Nlbr Ltd | Other services | 2017 |
| NLP Admin Limited | Administrative & support | 2011 |
| NM Mortgages Ltd. | Financial services | 2005 |
| NMD Brickwork Ltd | Construction | 2014 |
| NMG Consulting Ltd | Professional & scientific | 2020 |
| NMP Projects Ltd | Construction | 2023 |
| NMT Holdings Limited | Transport & logistics | 2018 |
| NMT International Limited | Transport & logistics | 2018 |
| NMT International Shipping UK Limited | Administrative & support | 2006 |
| NN Estimating Ltd | Construction | 2025 |
| NN Happy Cleaning Services Ltd | Administrative & support | 2023 |
| NNC Transport Ltd | Transport & logistics | 2025 |
| NO 7 Retail Limited | Wholesale & retail | 2016 |
| NO Added Sugar Marketing Limited | Professional & scientific | 2018 |
| NO Clothes Limited | Wholesale & retail | 2019 |
| NO Comment Records Ltd | Manufacturing | 2025 |
| NO Drama Llamas LLP | | 2021 |
| NO Limits (South) | Health & social care | 2001 |
| NO Limits Performance and Education Ltd | Education | 2025 |
| NO Limits Trading Limited | Education | 2018 |
| NO1 Carpet Cleaners Limited | Professional & scientific | 2019 |
| NO16 Church Street Limited | Hospitality | 2023 |
| Noadswood School | Education | 2011 |
| Noah Corp Ltd | Professional & scientific | 2025 |
| Noah's ARK Pre-School (Southampton) Limited | Health & social care | 2015 |
| Nobilis Care South Limited | Health & social care | 2008 |
| Noble & SON Building Contractors Ltd | Construction | 2025 |
| Noble Admin Solutions Ltd | Professional & scientific | 2020 |
| Noble Ground Investments Limited | Real estate | 2026 |
| Noble M&E Services Limited | Construction | 1998 |
| Noble Plastering & Drylining Ltd | Construction | 2023 |
| Noble Polythene Limited | Manufacturing | 1987 |
| Noblemore Ltd | Professional & scientific | 2010 |
| Nobores Limited | Other services | 2012 |
| Nobores Properties Limited | Real estate | 2020 |
| Nodescope Limited | Information & communication | 2005 |
| NOE Bebe Ltd | Transport & logistics | 2024 |
| NOH Services Ltd | Transport & logistics | 2017 |
| Noise & Vibration Calibration Services Ltd | Professional & scientific | 2020 |
| Noise Reduction UK Limited | Manufacturing | 2021 |
| Nola Property Services Ltd | Hospitality | 2023 |
| Nolans Emergency Accomodation Limited | Hospitality | 2014 |
| Nomad Temporary Housing Limited | Real estate | 2014 |
| Nomi Global Star Ltd | Manufacturing | 2023 |
| Nomit Ltd | Professional & scientific | 2022 |
| Noodle 8 the Broadway Ltd | Hospitality | 2018 |
| Nook & Cranny Bistro & Bar Ltd | Hospitality | 2025 |
| Noorza Solutions Ltd | Administrative & support | 2026 |
| Noproblem Software Limited | Information & communication | 1996 |
| Nord Studios Visuals Ltd | Information & communication | 2024 |
| Nordic Express Ltd | Transport & logistics | 2019 |
| Nordic Shine Ltd | Administrative & support | 2023 |
| Nori Active Ltd | Wholesale & retail | 2026 |
| Nori Construction Limited | Construction | 2014 |
| Norica Trans Ltd | Transport & logistics | 2015 |
| Norma Jeane Clothing Limited | Wholesale & retail | 2019 |
| Norman Road (Winchester) Residents Association Limited | Households | 1963 |
| Normans Freehold Limited | Real estate | 2004 |
| Normich Security Ltd | Information & communication | 2023 |
| Norris & Fisher (Insurance Brokers) Ltd | Financial services | 2002 |
| Norris & Fisher Holdings Limited | Financial services | 2022 |
| Norris Designs Limited | Administrative & support | 2011 |
| Nortek Instruments Limited | Wholesale & retail | 2002 |
| North Baddesley Service Centre Limited | Wholesale & retail | 2010 |
| North East Corner Media Ltd | Professional & scientific | 2025 |
| North Stour Limited | Hospitality | 2024 |
| North Street Havant Limited | Construction | 2018 |
| Northam Beer Co Ltd | Manufacturing | 2024 |
| Northam Business Centre Management Company Limited | Real estate | 1988 |
| Northbright Care PVT Ltd | Health & social care | 2013 |