| Nestfield Properties Ltd | Real estate | 2026 |
| NET0 Carbon Consulting Ltd | Professional & scientific | 2026 |
| Network Technologies and Associates Limited | Wholesale & retail | 1993 |
| Neutral Limited | Information & communication | 1927 |
| Neville's Window Cleaning Services Limited | Professional & scientific | 2005 |
| New Chelsea TB Ltd | Arts & recreation | 2021 |
| New England Barns Management Company Limited | Households | 2019 |
| New Platelet Company Ltd | Manufacturing | 2023 |
| New Smart Digital Services Ltd | Professional & scientific | 2026 |
| Newcampe Medical Limited | Health & social care | 1991 |
| Newell House Ltd | Financial services | 2023 |
| Newmarket 875 Limited | Manufacturing | 2022 |
| Newmarket Advertising Limited | Hospitality | 2022 |
| Newmarket Best Taxi Limited | Transport & logistics | 2025 |
| Newmarket BID Limited | Other services | 2016 |
| Newmarket Boutique Apartments Limited | Arts & recreation | 2022 |
| Newmarket Cabs Ltd | Transport & logistics | 2023 |
| Newmarket Camper & Conversions Ltd | Extraterritorial | 2022 |
| Newmarket Captain Ltd | Transport & logistics | 2025 |
| Newmarket Catering Limited | Hospitality | 2019 |
| Newmarket Chalk Streams CIC | Information & communication | 2025 |
| Newmarket Community Services Ltd | Transport & logistics | 2015 |
| Newmarket Decorators Limited | Construction | 2008 |
| Newmarket Dessert Limited | Hospitality | 2023 |
| Newmarket Digital Limited | Information & communication | 2013 |
| Newmarket Entertainment Limited | Hospitality | 2014 |
| Newmarket Equine Clinic Holdings Limited | Financial services | 2023 |
| Newmarket Equine Clinic Limited | Professional & scientific | 2006 |
| Newmarket Event Hire Limited | Administrative & support | 2025 |
| Newmarket Executive Travel Limited | Transport & logistics | 2023 |
| Newmarket Garden Machinery Services Limited | Wholesale & retail | 1971 |
| Newmarket Gateway Trust | Arts & recreation | 2003 |
| Newmarket Heritage Taxis Ltd | Transport & logistics | 2025 |
| Newmarket Housing Trust | Real estate | 2024 |
| Newmarket International Ltd | Wholesale & retail | 2025 |
| Newmarket Islamic Cultural Centre | Health & social care | 2013 |
| Newmarket Land Management Company Limited | Real estate | 2022 |
| Newmarket Lawn Tennis Club Limited(The) | Arts & recreation | 1948 |
| Newmarket Management Company Limited(The) | Households | 1972 |
| Newmarket Motor Company Limited | Wholesale & retail | 2004 |
| Newmarket Motorcycle Company Limited | Manufacturing | 2019 |
| Newmarket Motorhomes Ltd | Wholesale & retail | 2025 |
| Newmarket Nexus, Connecting Young People C.I.C. | Wholesale & retail | 2024 |
| Newmarket Open Door | Hospitality | 1998 |
| Newmarket Pizza and Curry House Limited | Hospitality | 2024 |
| Newmarket Plumbing and Heating Limited | Construction | 2012 |
| Newmarket Private Dementia Assessment and Treatment Clinic Ltd | Health & social care | 2025 |
| Newmarket Racecourses Limited | Arts & recreation | 1965 |
| Newmarket Racing Club Limited | Professional & scientific | 2014 |
| Newmarket Secret Kitchen Ltd | Hospitality | 2019 |
| Newmarket Skin Deep Clinic Ltd. | Other services | 2017 |
| Newmarket Spice Limited | Hospitality | 2018 |
| Newmarket Sports & Media Ltd | Professional & scientific | 2002 |
| Newmarket Stablecare Limited | Other services | 2011 |
| Newmarket Stores Ltd | Wholesale & retail | 2025 |
| Newmarket Stud Farmers' Association Limited | Agriculture & fishing | 2012 |
| Newmarket Suffolk Cabs Ltd | Transport & logistics | 2025 |
| Newmarket Suffolk Taxi Ltd | Transport & logistics | 2016 |
| Newmarket Taxis Ltd | Transport & logistics | 2026 |
| Newmarket Thoroughbred Racing & Breeding Industry Community Interest Company | Other services | 2026 |
| Newmarket Thoroughbred Racing PLC | | 1986 |
| Newmarket Trailers Limited | Wholesale & retail | 2022 |
| Newmarket Tyres Ltd | Wholesale & retail | 2024 |
| Newmarket Venues Limited | Hospitality | 2024 |
| Newmarketing Campaign Limited | Professional & scientific | 2000 |
| Newprint Digital Limited | Manufacturing | 2018 |
| Newprint Limited | Manufacturing | 2013 |
| Newtax Limited | Transport & logistics | 2002 |
| Newton (Halesowen) Limited | Real estate | 2023 |
| Nexado Limited | Wholesale & retail | 2025 |
| Nexfaze Ltd | Professional & scientific | 2026 |
| Nextphase AI Limited | Information & communication | 2025 |
| Nexus Community Services Limited | Water & waste | 2026 |
| NGC Fencing Ltd | Construction | 2024 |
| NH Ltd | Extraterritorial | 2009 |
| NH3 Engineering Ltd | Construction | 2015 |
| Nicholls Motion Pictures Limited | Information & communication | 2025 |
| Nicholson Building Limited | Construction | 1997 |
| Nicky Swinburn Limited | Hospitality | 2010 |
| Nikita Patel Pharma Limited | Administrative & support | 2021 |
| Nine Miles Group Limited | Wholesale & retail | 2026 |
| NJC Carpentry Limited | Construction | 2014 |
| NL Limited | Extraterritorial | 2007 |
| NMB Design Ltd | Professional & scientific | 2025 |
| NMD Lettings Limited | Real estate | 2025 |
| Nobelus Europe Ltd | Wholesale & retail | 2023 |
| Nobelus Holdings Ltd | Financial services | 2024 |
| Noble Horizons Ltd | Health & social care | 2015 |
| Nonovium Ltd | Information & communication | 2020 |
| Normark Ventures Limited | Real estate | 2025 |
| Notsosolo Ltd | Administrative & support | 2025 |
| Nottingham Racecourse Company Limited | Arts & recreation | 1967 |
| Nova by Nexus Ltd | Education | 2026 |
| Novel Technologies Centre UK Limited | Professional & scientific | 2016 |
| Novex Ventures Limited | Professional & scientific | 2025 |
| Novo Retreat Limited | Real estate | 2021 |
| NP Ltd | Extraterritorial | 2008 |
| NP Nunn Ltd | Agriculture & fishing | 2007 |
| NPH Group Ltd | Professional & scientific | 1990 |
| Nrgise Electrical Services Ltd | Construction | 2016 |