| NGP Management Company (Commercial) Limited | Real estate | 2007 |
| NGP Management Company (Town Centre) Limited | Real estate | 2007 |
| NGP Management Company Residential (Cell G) Limited | Real estate | 2007 |
| NGP Residential Limited | Real estate | 2023 |
| Ngslogistics Ltd | Transport & logistics | 2025 |
| Ngualla Group UK Limited | Mining & quarrying | 2021 |
| Nguvu Limited | Households | 2019 |
| Nguyen's Property Limited | Real estate | 2025 |
| NGX Exploration UK Limited | Mining & quarrying | 2021 |
| NGX Holdings UK Limited | Financial services | 2021 |
| NGX Kenya Exploration UK Limited | Mining & quarrying | 2024 |
| NGX Kenya Holdings UK Limited | Financial services | 2024 |
| NGX Mining UK Limited | Mining & quarrying | 2021 |
| NGX Uranium Exploration UK Limited | Mining & quarrying | 2024 |
| NGX Uranium Holdings UK Limited | Financial services | 2024 |
| NH Bidco Limited | Professional & scientific | 2021 |
| NH Holdco Limited | Professional & scientific | 2021 |
| NH International Limited | Construction | 1973 |
| NH Parentco Limited | Professional & scientific | 2021 |
| NH Properties Limited | Real estate | 2019 |
| NHC Retail Limited | Wholesale & retail | 2024 |
| NHH Land Partners Ltd | Construction | 2026 |
| NHI Property Services Limited | Real estate | 2024 |
| NI Creative Limited | Professional & scientific | 2026 |
| Nial Finance Limited | Transport & logistics | 2006 |
| Nial Group Limited | Transport & logistics | 2006 |
| Nial Services Limited | Transport & logistics | 1991 |
| Nibblio Treats Ltd | Manufacturing | 2026 |
| Nic's Dog Care Ltd | Other services | 2022 |
| Nice Noodle Chinese Limited | Hospitality | 2026 |
| Nice Swan Academy Ltd | Arts & recreation | 2016 |
| Nice Swan Ltd | Arts & recreation | 2021 |
| Niche Go Ltd | Wholesale & retail | 2020 |
| Niche Legal Consultancy Ltd | Professional & scientific | 2020 |
| Nicholas & Co (North East) Limited | Real estate | 2015 |
| Nicholas (Newcastle) Ltd | Administrative & support | 2016 |
| Nicholas Pugh Design Consultant Ltd | Professional & scientific | 2021 |
| Nicholas Williams Surgery Ltd | Health & social care | 2014 |
| Nicholson Media Ltd | Information & communication | 2022 |
| Nick Addis Hairdressing Ltd | Other services | 2020 |
| Nick Kalson Surgery Limited | Health & social care | 2024 |
| Nick Todd Ltd | Health & social care | 2022 |
| Nickazon Ltd | Wholesale & retail | 2018 |
| Nickel Properties & Letting Ltd | Real estate | 2014 |
| Nicklin Furniture Limited | Manufacturing | 2008 |
| Nicola Bottazzi Limited | Health & social care | 2024 |
| Nicola Hall Hairdressing Ltd | Other services | 2026 |
| Nicolae Cleaning Limited | Administrative & support | 2025 |
| Nicor Geotechnical Ltd | Professional & scientific | 2019 |
| Nicovate Limited | Information & communication | 2018 |
| Nida Travel Ltd | Administrative & support | 2025 |
| Nidan Properties Limited | Construction | 2025 |
| Nidsdale 1968 Limited | Extraterritorial | 2014 |
| Nidus Riley Limited | Professional & scientific | 2006 |
| Nifty Fixes NE Ltd | Construction | 2025 |
| Nigel Cabourn Limited | Professional & scientific | 2000 |
| Nigel Frank International Limited | Administrative & support | 2006 |
| Nigel Lightfoot Associates Limited | Health & social care | 2010 |
| Nigel Temporary Works Engineers Ltd | Professional & scientific | 2025 |
| Nigel Wright Consultancy Limited | Administrative & support | 1999 |
| Nigel Wright Employment Services Limited | Administrative & support | 2007 |
| Nigel Wright Group Holdings Limited | Professional & scientific | 2009 |
| Nigel Wright Group Limited | Professional & scientific | 2009 |
| Nigel Wright International Limited | Administrative & support | 2009 |
| Nigerian Association Tyne and Wear CIC | Education | 2024 |
| Night and Day Newcastle Limited | Health & social care | 2023 |
| Nightingale Aura Limited | Professional & scientific | 2025 |
| Nightingale Chase (Guisborough) Management Company Limited | Real estate | 2025 |
| Nihao Ltd | Wholesale & retail | 2022 |
| Nihude Services Limited | Wholesale & retail | 2022 |
| Nikeash Ltd | Health & social care | 2026 |
| Nile Medical Solution Limited | Health & social care | 2026 |
| Nile Vanguard Ltd | Financial services | 2025 |
| Nileexpressmovers Limited | Transport & logistics | 2015 |
| Nilemont Industries Ltd | Wholesale & retail | 2025 |
| Nilus Developments Limited | Construction | 2016 |
| Nimo Safeguarding Ltd | Professional & scientific | 2025 |
| Nimtek Investment Limited | Real estate | 2022 |
| Nimtek Limited | Wholesale & retail | 2010 |
| Nina S Property Management Limited | Real estate | 2020 |
| Nine Fold Clothing Ltd | Wholesale & retail | 2025 |
| Nineteen Bespoke Care Limited | Other services | 2024 |
| Ninetyseven Travel Limited | Administrative & support | 2013 |
| Ninja Boiler Replacement & Repair Ltd | Construction | 2023 |
| Ninja OPS Ltd | Transport & logistics | 2026 |
| Ninjatcg Ltd | Wholesale & retail | 2025 |
| Ninkasi Pubco Limited | Hospitality | 2013 |
| Ninth Planet Engineering Limited | Professional & scientific | 2016 |
| Nipa Steakhouse Ltd | Hospitality | 2026 |
| Nipa Trading Company Ltd | Wholesale & retail | 2025 |
| Nishman Barbers Limited | Other services | 2020 |
| Nishwanth UK Ltd | Wholesale & retail | 2025 |
| Nisne IT Solutions Ltd | Information & communication | 2014 |
| Nitelites Group Limited | Arts & recreation | 2020 |
| Nitelites Limited | Professional & scientific | 2004 |
| Nithy Ltd | Wholesale & retail | 2015 |
| Nivaatu Corporation Limited | Extraterritorial | 1998 |
| Nivaaytu Holdings Limited | Financial services | 2026 |
| Niveau Property Limited | Real estate | 2023 |
| Niwe Eating Distress Service Trading AS Eating Distress North East Limited | Health & social care | 2012 |