| Nishma Ltd | Extraterritorial | 2024 |
| Nishvis Limited | Wholesale & retail | 2023 |
| Nismah CIC | Education | 2026 |
| Nissin Services Ltd | Transport & logistics | 2015 |
| Nita K Property Holdings Limited | Real estate | 2016 |
| Nita K Property Management Limited | Households | 2023 |
| Nitrate Film Limited | Information & communication | 1984 |
| Nitrate London Limited | Information & communication | 2011 |
| NJI Environmental Limited | Professional & scientific | 2017 |
| Njpn Foods Ltd | Hospitality | 2025 |
| NJY Consulting Ltd | Professional & scientific | 2020 |
| NJZ Investments Limited | Financial services | 2025 |
| NK Plastering Services Limited | Construction | 2017 |
| NK Star Group Limited | Real estate | 2025 |
| Nkalkan Ltd | Extraterritorial | 2024 |
| NKI Limited | Real estate | 2025 |
| Nkla Healthcare Limited | Administrative & support | 2017 |
| Nkmp Holdings Limited | Financial services | 2025 |
| NLP Professional Services Limited | Other services | 2021 |
| Nm:Am Talent Consultancy Ltd | Administrative & support | 2020 |
| NMF Medical Ltd | Health & social care | 2022 |
| NMS Solutions Limited | Professional & scientific | 2015 |
| NN Protect Ltd | Financial services | 2025 |
| Nnkm Properties Limited | Real estate | 2025 |
| NNP London Limited | Real estate | 2022 |
| NO 1 MOT Limited | Wholesale & retail | 2011 |
| NO.6 Cavendish House Limited | Wholesale & retail | 2019 |
| Noblemkt Ltd | Wholesale & retail | 2023 |
| Noblesap Ltd | Information & communication | 2017 |
| Noise and Pulsation Control Limited | Manufacturing | 1987 |
| NOM Kins Ltd | Manufacturing | 2025 |
| Nomadic Fabrics Ltd | Wholesale & retail | 2021 |
| Noman Property Investments Limited | Real estate | 2001 |
| Non-Stick Drink Things Limited | Hospitality | 2025 |
| Nonaaru Limited | Real estate | 2021 |
| Noname Ideas Ltd | Information & communication | 2020 |
| Noorova Ltd | Professional & scientific | 2025 |
| Nora Assets Ltd | Real estate | 2025 |
| Norcrest Services Ltd | Professional & scientific | 2023 |
| Norcrestproperty Limited | Real estate | 2022 |
| Norfolk Heron Limited | Professional & scientific | 2023 |
| Norma Investments Limited | Real estate | 2023 |
| Normans News Limited | Wholesale & retail | 2002 |
| North East Property Associates Ltd | Real estate | 2003 |
| North END Lodge (Pinner) Limited | Households | 1999 |
| North Herts Four Limited | Real estate | 2026 |
| North Hkfb Ltd | Other services | 2020 |
| North Hyde Developements Limited | Real estate | 2025 |
| North London Anaesthetic Service Limited | Administrative & support | 2010 |
| North London Critical Care Consulting Ltd | Health & social care | 2012 |
| North West Carpets Ltd | Wholesale & retail | 2024 |
| North West London Healthcare Ltd | Health & social care | 2013 |
| North West Property (London) LLP | | 2007 |
| Northolt Properties Ltd | Real estate | 2014 |
| Northspark Electrical Ltd | Construction | 2026 |
| Northwood Deer Properties Ltd | Real estate | 2022 |
| Northwood Homes Limited | Real estate | 2004 |
| Norton & Associates Limited | Professional & scientific | 2000 |
| Norvarage (UK) Limited | Real estate | 1995 |
| NOS Curare Ltd | Health & social care | 2016 |
| Nostro Technology Limited | Information & communication | 2006 |
| Notting Hill Build & Repair Ltd | Construction | 2025 |
| Nova Horizons Stays Ltd | Real estate | 2026 |
| Nova Recovery Limited | Health & social care | 2020 |
| Novapproach Limited | Professional & scientific | 2010 |
| Novapproach Solutions Ltd | Professional & scientific | 2021 |
| Novel Animation Limited | Administrative & support | 2004 |
| Novel Dental Group Limited | Health & social care | 2016 |
| Novel Entertainment Ltd | Information & communication | 2001 |
| Novel Film Holding Ltd | Information & communication | 2020 |
| Novel Production House Ltd | Information & communication | 2021 |
| Novel Rights Ltd | Information & communication | 2022 |
| Novus Vita Ltd | Professional & scientific | 2017 |
| Novuspharma (UK) Ltd | Wholesale & retail | 2020 |
| NOW Follow Your Bliss Ltd | Health & social care | 2015 |
| NOW ITS Time Ltd | Real estate | 2020 |
| NOW Known Limited | Wholesale & retail | 2020 |
| Nower Hill High School | Education | 2011 |
| NP & KP Investments Limited | Construction | 2016 |
| Npns Property Ltd | Real estate | 2025 |
| Nrsimha Holdings Ltd | Financial services | 2026 |
| NRV Consultancy Ltd | Professional & scientific | 2026 |
| NS Health Solutions Limited | Health & social care | 2020 |
| NTD Builds Limited | Construction | 2024 |
| NTR Management Limited | Real estate | 2019 |
| NTX Academy Ltd | Education | 2025 |
| Nuala Limited | Arts & recreation | 2012 |
| Nuba Investments Ltd | Real estate | 2023 |
| Nucleus Property Holdings Limited | Real estate | 2022 |
| Nuevo Line Solutions Limited | Professional & scientific | 2025 |
| Numbr ADS Ltd | Professional & scientific | 2022 |
| Numen Financial Limited | Financial services | 2015 |
| Numen Properties Limited | Real estate | 2023 |
| Numeris Digital Limited | Information & communication | 2026 |
| Numial Limited | Professional & scientific | 2015 |
| Nuris Coffee Limited | Hospitality | 2017 |
| Nurturing Change Limited | Health & social care | 2025 |
| Nutri Home Care Ltd | Professional & scientific | 2025 |
| Nutriberry Ltd | Wholesale & retail | 2024 |
| Nutrifit Clinic Ltd | Other services | 2013 |