| Myddleton Grange Management Company Limited | Households | 1996 |
| Myfamilyhart Healthcare Ltd | Health & social care | 2026 |
| Myholiday Ltd | Extraterritorial | 2022 |
| Mystic Beauty Ltd | Wholesale & retail | 2017 |
| N L Electrical Services Ltd | Construction | 2016 |
| N M Bannister Limited | Professional & scientific | 2025 |
| N.J Removal Limited | Transport & logistics | 2022 |
| N90 Strategic Ltd | Administrative & support | 2021 |
| NA Howes Interiors Ltd | Construction | 2007 |
| NAC Home Improvements Ltd | Construction | 2023 |
| Namubiru Holdings Ltd | Health & social care | 2022 |
| National Drinks Distribution Ltd | Wholesale & retail | 2022 |
| Nationwide Cleaners Central Ltd | Administrative & support | 2015 |
| Natural Affinity Pharma Limited | Wholesale & retail | 2014 |
| Nature Fit Ltd | Health & social care | 2022 |
| NB Plumbing and Heating Services Ltd | Construction | 2024 |
| Nedas Petrauskas Ltd | Construction | 2025 |
| NEE Formwork Limited | Construction | 2002 |
| Need a Little Hand Limited | Administrative & support | 2016 |
| Needingworth Campers Ltd | Wholesale & retail | 2014 |
| Needingworth Limited | Professional & scientific | 2013 |
| Needwood Group Ltd | Construction | 2016 |
| Nehro Ltd | Wholesale & retail | 2025 |
| Neighbour's Flavours Ltd | Hospitality | 2026 |
| Nelevation Limited | Administrative & support | 2016 |
| Nene Valley Limited | Professional & scientific | 2012 |
| Nene Valley Property Investments Limited | Real estate | 2020 |
| Neotists CIC | Education | 2018 |
| Nervous REX Ltd | Wholesale & retail | 2021 |
| Nestmakers Realty Ltd | Administrative & support | 2025 |
| Netceed UK Limited | Information & communication | 1978 |
| Nether Carswell Three Limited | Energy | 2013 |
| Nettos Consultancy Services Limited | Administrative & support | 2020 |
| Nettos Financial Services Ltd | Information & communication | 2019 |
| Nettos Tours and Travels Ltd | Hospitality | 2020 |
| Network Service Solutions Ltd | Information & communication | 2010 |
| Neuro Coral Psychology Ltd | Health & social care | 2023 |
| New Build & Renovations Limited | Construction | 2015 |
| New Chapter Healthcare Ltd | Administrative & support | 2026 |
| New ELM Holdings Limited | Financial services | 2023 |
| New Frequency Ltd | Public administration | 2026 |
| New Heights Wellness Limited | Health & social care | 2016 |
| New Leaf Cleaning Solutions Ltd | Administrative & support | 2025 |
| New Miahs Kitchen Ltd | Hospitality | 2025 |
| New Pond Farm (1997) Limited | Agriculture & fishing | 1997 |
| New Spine Wellness Ltd | Other services | 2023 |
| New ST Marys Care Home Limited | Construction | 2024 |
| New Wings Garden Ltd | Hospitality | 2025 |
| Neways Associates Limited | Construction | 2002 |
| Newcom Holdings Limited | Financial services | 2024 |
| Newham Hall Holdings Limited | Real estate | 2013 |
| Newham Hall Holdings Top Company Ltd | Manufacturing | 2025 |
| Newlove Fitness Ltd | Health & social care | 2024 |
| Newshound Media Ltd | Information & communication | 2019 |
| Next Greentech Limited | Wholesale & retail | 2025 |
| Nextbatch Ltd | Wholesale & retail | 2025 |
| Nextquest World Ltd | Administrative & support | 2026 |
| NIC FLO Services Limited | Transport & logistics | 2018 |
| Niche Venues Limited | Hospitality | 2006 |
| Nicholson Property Investors Ltd | Real estate | 2018 |
| Nick Knight Security Consultancy Ltd | Administrative & support | 2022 |
| Nickourier Ltd | Transport & logistics | 2023 |
| Nicoles Wellness Store Ltd | Manufacturing | 2024 |
| Nimble IT Ltd | Information & communication | 2022 |
| Nimbusone Ltd | Information & communication | 2025 |
| Ninespire Projects Ltd | Professional & scientific | 2011 |
| Nirbhau Consultancy Limited | Professional & scientific | 2025 |
| Nirmala Lettings Limited | Real estate | 2024 |
| Nirmala Medical Ltd | Health & social care | 2021 |
| Nirvan Cyber Security Solutions PVT. Ltd | Information & communication | 2025 |
| Nivo Management Limited | Professional & scientific | 2023 |
| NJ Rail Consulting Ltd | Professional & scientific | 2025 |
| NJM Optical Limited | Wholesale & retail | 2018 |
| NK Accountancy Services Ltd | Professional & scientific | 2017 |
| NK Golf Limited | Arts & recreation | 2013 |
| NK Scaffolding Limited | Construction | 2018 |
| NM Flooring Services Ltd | Construction | 2013 |
| NM2LOGIC Ltd | Information & communication | 2013 |
| NO Nonsense Property Solutions Ltd | Real estate | 2023 |
| NO Smoke PFP Limited | Construction | 2024 |
| Noah James Technology Insights Ltd | Information & communication | 2024 |
| Noble FOX Liverpool Limited | Wholesale & retail | 2017 |
| Noccex Ltd | Transport & logistics | 2026 |
| Nogard Creations Ltd | Wholesale & retail | 2024 |
| NOH Limited | Information & communication | 2004 |
| Nokes Solutions Ltd | Professional & scientific | 2024 |
| NON Metallic Ltd | Information & communication | 2025 |
| Norest Mararike Ltd | Other services | 2024 |
| Norfolk Coastal Escape Limited | Hospitality | 2016 |
| North and East Properties Limited | Financial services | 2025 |
| North Lodge Estates Limited | Households | 2005 |
| North Sea Seafood Limited | Wholesale & retail | 2015 |
| Northampton Crane Hire Ltd | Administrative & support | 2008 |
| Northamptonshire Home Help Ltd | Administrative & support | 2026 |
| Northcrest Healthcare Limited | Health & social care | 2019 |
| Northern Line Records Limited | Arts & recreation | 2016 |
| Northlight Partners Ltd | Administrative & support | 2024 |
| Northstowe Arts CIC | Arts & recreation | 2022 |
| Notad Healthcare Ltd | Other services | 2018 |
| Notfot Services Ltd | Other services | 2021 |