| Nightingale Place (Haddenham) Management Company Limited | Households | 2016 |
| Nightingale Place Properties Limited | Construction | 2012 |
| Nightsafe Security Solutions Ltd | Administrative & support | 2025 |
| Nightsky Research Ltd | Professional & scientific | 2026 |
| NIK Cooper Photography Ltd | Professional & scientific | 2025 |
| Nikki Perry Limited | Hospitality | 2019 |
| Nile Trading UK Limited | Wholesale & retail | 2007 |
| Nina Jenkins Creative Limited | Professional & scientific | 2018 |
| Nina Sweet Ltd | Hospitality | 2024 |
| Niron UK Limited | Transport & logistics | 2013 |
| Niruja Limited | Real estate | 2026 |
| Nisa Collection Ltd | Wholesale & retail | 2026 |
| Nishaas Ltd | Health & social care | 2024 |
| Nitnot Ltd | Other services | 2018 |
| Nityananda Limited | Health & social care | 2024 |
| Nivalis Ltd | Wholesale & retail | 2023 |
| NJ Construct Ltd | Real estate | 2025 |
| Njhellolondon Ltd | Wholesale & retail | 2019 |
| NJW Building & Lettings Ltd | Construction | 2025 |
| NJY Properties Ltd | Real estate | 2018 |
| NK Residential Limited | Real estate | 2024 |
| Nkrcs Solutions Limited | Information & communication | 2025 |
| NLM Construction Ltd | Construction | 2025 |
| NLP Capital Limited | Financial services | 2026 |
| NLP Consultancy Limited | Professional & scientific | 2024 |
| NLP4KIDS Ltd | Education | 2011 |
| NM88 Finance Ltd | Professional & scientific | 2023 |
| NMA Counselling Limited | Health & social care | 2024 |
| NMJ Consultancy (UK) Ltd. | Professional & scientific | 2012 |
| Nmpcfs Ltd | Administrative & support | 2015 |
| Nmwoods Ltd | Wholesale & retail | 2023 |
| NN Travel Ltd | Transport & logistics | 2014 |
| Nnmistry Ltd | Professional & scientific | 2019 |
| NO Butts Services Limited | Professional & scientific | 2010 |
| NO Gears Driving School Ltd | Other services | 2006 |
| Noble Building Projects Limited | Construction | 2005 |
| Noble Plumbing Ltd | Construction | 2011 |
| Noble Windows & Conservatories Limited | Extraterritorial | 2011 |
| Noel J Turner Limited | Manufacturing | 2012 |
| Noemi.Sulejmani Ltd | Construction | 2025 |
| Noggo Properties Limited | Real estate | 2017 |
| Nolimit Training Limited | Education | 2025 |
| Nollywood UK Productions Limited | Information & communication | 2006 |
| Nolton Innovations Ltd | Transport & logistics | 2015 |
| Noma Creations Ltd | Manufacturing | 2024 |
| Nomonde Legal Services Ltd | Professional & scientific | 2026 |
| Nonnalina Deliveries Ltd | Hospitality | 2020 |
| Noor Commercial Limited | Real estate | 2023 |
| Noor Logistics Ltd | Transport & logistics | 2023 |
| Noraxpebble Event Ltd | Hospitality | 2025 |
| Norcliff Court RTM Company Limited | Households | 2020 |
| Norsta Group Ltd | Professional & scientific | 2024 |
| North 3 Ltd | Hospitality | 2026 |
| North Construction & Development Limited | Construction | 2002 |
| North London Electrical Limited | Construction | 2017 |
| North Star Locations Ltd | Other services | 2020 |
| North Thames Heating Ltd | Construction | 2018 |
| Northbridge Property Management Ltd | Real estate | 2026 |
| Northfields (Colchester) Management Company Limited | Households | 2009 |
| Northgate Public Services Limited | Information & communication | 2014 |
| Northpoint Brands Ltd | Wholesale & retail | 2025 |
| Northridge Electrical Services Limited | Construction | 2013 |
| Northridge Property Solutions Limited | Extraterritorial | 2011 |
| Northridge Recruitment Limited | Administrative & support | 2020 |
| Northstowe H5 Residents Management Company Limited | Households | 2023 |
| Norton Rise (Management Company) Limited | Households | 2019 |
| Norwood Consultants Limited | Professional & scientific | 1993 |
| Nosebek Transport Ltd | Transport & logistics | 2025 |
| Nostop Music Group Ltd | Information & communication | 2024 |
| Notreve Limited | Information & communication | 2008 |
| Noun Properties Limited | Real estate | 2024 |
| Nourish Animal Health Ltd | Manufacturing | 2019 |
| Nourish Recruitment Ltd | Administrative & support | 2023 |
| Nourish to Nurture Nutrition Ltd | Health & social care | 2025 |
| Nova Transport Services Ltd | Transport & logistics | 2022 |
| Nova YOU Aesthetics Ltd | Other services | 2023 |
| Novahex Supplements Ltd | Wholesale & retail | 2026 |
| Novaroute Couriers Ltd | Transport & logistics | 2026 |
| Novate ACS Ltd | Construction | 2020 |
| Novatec Recruitment Ltd | Administrative & support | 2024 |
| Novated Procurements Ltd | Construction | 2025 |
| Novum Power Systems Ltd | Construction | 2026 |
| Novus Partnership Limited | Administrative & support | 2020 |
| Nowak Store Limited | Wholesale & retail | 2024 |
| Nowvertical UK Holdings Ltd | Information & communication | 2022 |
| Nowvertical UK Ltd | Information & communication | 2021 |
| NPE Electrics Ltd | Construction | 2020 |
| NPS (Holdings) Limited | Information & communication | 2014 |
| NPS Pension Trustees Limited | Financial services | 2015 |
| NRG Powerjet Ltd | Water & waste | 2018 |
| NRI International Limited | Financial services | 2016 |
| NRK Communications Limited | Professional & scientific | 2021 |
| NRK Media Services Limited | Information & communication | 2017 |
| NS Essence Ltd | Real estate | 2026 |
| Nu-World CIC | Education | 2020 |
| Nu-Worx Construction Ltd | Construction | 2025 |
| Nugget Golf Ltd | Information & communication | 2022 |
| NUMBER1UK Ltd | Administrative & support | 2017 |
| Numbermill Accounting Ltd | Professional & scientific | 2014 |
| Numbermill Limited | Administrative & support | 2014 |