| Neuroformed Ltd | Information & communication | 2012 |
| New Heat Renewable Services Limited | Other services | 2025 |
| New Heat Renewable Solutions Limited | Other services | 2025 |
| New Josh Spice Ltd | Hospitality | 2018 |
| New Road Harlington Management Ltd | Households | 2007 |
| New Village Logistics Limited | Transport & logistics | 2021 |
| New Wharf Brewing Company Limited | Manufacturing | 2016 |
| New York's Nails Ltd | Other services | 2017 |
| Newave Properties Limited | Real estate | 2023 |
| Newberry Consultancy Ltd | Professional & scientific | 2025 |
| Newhealth Group Ltd | Health & social care | 2026 |
| Newlife Care Services (Holding Co) Limited | Financial services | 2003 |
| Newlife Care Services Limited | Health & social care | 1993 |
| Newlook Holdings Ltd | Real estate | 2015 |
| Newton Audit Consultancy Services Ltd | Administrative & support | 2019 |
| Next Level Camps Ltd | Education | 2023 |
| Next Level Sports Performance Limited | Education | 2019 |
| Next Phase Advisory Limited | Professional & scientific | 2025 |
| Next Wave Sports & Media Limited | Professional & scientific | 2024 |
| Nextfrontierai Ltd | Information & communication | 2026 |
| Nextherm Solutions Limited | Construction | 2026 |
| Nextnest Builders Ltd | Construction | 2025 |
| Nexus Executive Cars Ltd | Transport & logistics | 2024 |
| Nexus Securely Ltd | Information & communication | 2024 |
| NFM CTD Ltd | Arts & recreation | 2014 |
| Nightingale House (Windsor) Management Company Limited | Households | 2013 |
| Nightingale Luxury Travel Limited | Administrative & support | 2025 |
| Nightingale Property Services Ltd | Real estate | 2018 |
| NIL & DAL Ltd | Hospitality | 2018 |
| Nimblesix Limited | Other services | 2026 |
| Niobium Metallurgical Resources Limited | Manufacturing | 2025 |
| Niraaj Properties Limited | Real estate | 2004 |
| Nish Health Limited | Health & social care | 2017 |
| Nish Investments Ltd | Real estate | 2013 |
| Nish Property Ltd | Real estate | 2019 |
| Nissicross Limited | Real estate | 2018 |
| Nite N Day (Dedworth) Limited | Wholesale & retail | 2019 |
| NJM (UK) Limited | Construction | 1998 |
| NJP Accounts Ltd | Professional & scientific | 2016 |
| NJS Media Ltd | Arts & recreation | 2011 |
| NK Investment Property Limited | Real estate | 2019 |
| NK Labs Technologies Ltd | Information & communication | 2026 |
| NL Performance Consulting Ltd | Arts & recreation | 2011 |
| NM Building Services Ltd | Construction | 2023 |
| NM Mitchell Consultancy Ltd | Information & communication | 2022 |
| Nm&L Ltd | Households | 2023 |
| NMA Intertrading Ltd | Wholesale & retail | 2026 |
| NN Asset Holding Ltd | Real estate | 2020 |
| Nnah Services Limited | Professional & scientific | 2013 |
| NO. 1 Monkey Island Lane Management Company Limited | Households | 2002 |
| NO. 25 Beauty Lounge Ltd | Other services | 2023 |
| Nokesbridge Ltd | Wholesale & retail | 2025 |
| NOM Coaching Ltd | Professional & scientific | 2026 |
| Nomad Gifts Limited | Wholesale & retail | 2022 |
| Nonsuch (Management Company) Limited | Households | 2004 |
| Noorco Ltd | Real estate | 2007 |
| Norstar Advisory Services Limited | Professional & scientific | 2024 |
| North Heath Holdings Limited | Financial services | 2019 |
| North Star People Development Limited | Other services | 2016 |
| Northern ARC Housing Ltd | Real estate | 2024 |
| Northlands Meadows Limited | Other services | 2021 |
| Nosto Solutions UK Ltd | Information & communication | 2017 |
| Note Stonehouse Limited | Manufacturing | 2024 |
| Note UK Holding Limited | Manufacturing | 2004 |
| Notetech Solutions Ltd | Manufacturing | 2015 |
| Noura Housing Ltd | Real estate | 2024 |
| Nova Electrical Group Ltd | Construction | 2020 |
| Novita Associates Limited | Administrative & support | 2006 |
| Nowt Ventures Ltd | Manufacturing | 2021 |
| NR Technical Support Ltd | Manufacturing | 2014 |
| NRS Eco Ltd | Construction | 2020 |
| NRS Logistics UK Ltd | Wholesale & retail | 2026 |
| NTB Plumbing & Heating Ltd Ltd | Construction | 2024 |
| Nublo Ltd | Extraterritorial | 2020 |
| Nuffield Centre Dyspraxia Programme Limited | Professional & scientific | 2004 |
| Nuit Analytics Ltd | Information & communication | 2021 |
| Nullius Partners Ltd | Professional & scientific | 2026 |
| Number 19 Wine Bar Limited | Hospitality | 2020 |
| Number 8 Group Limited | Other services | 2008 |
| Number 8 Recruitment Limited | Other services | 2008 |
| Number 8 Resourcing Limited | Administrative & support | 2009 |
| Numeratics Limited | Professional & scientific | 2013 |
| Numi Consulting Ltd | Information & communication | 2020 |
| Numi Holdings Limited | Financial services | 2024 |
| Nursery Gardens (Hurst) Management Company Limited | Households | 2021 |
| Nuth Brothers Limited | Hospitality | 2013 |
| Nutrinder Limited | Health & social care | 2015 |
| Nutrition for Performance Ltd | Health & social care | 2020 |
| Nutts About Property Ltd | Real estate | 2021 |
| NVC Sport Ltd | Education | 2026 |
| NVN Beaconsfield Limited | Hospitality | 2025 |
| NVN Holding Limited | Financial services | 2025 |
| NVN Leeds Limited | Hospitality | 2025 |
| NW6 Management Limited | Real estate | 2019 |
| NXT LEV Ltd | Arts & recreation | 2019 |
| NXT LEV Properties Ltd | Real estate | 2021 |
| O'Brien Bars Limited | Hospitality | 2024 |
| O.L.S Aviation Ltd | Transport & logistics | 2021 |
| Oakes Design Limited | Public administration | 2011 |
| Oakfield Park Gardens (Flats) Management Limited | Households | 1996 |