| Mythri Handicrafts Limited | Wholesale & retail | 2015 |
| Mytime Active | Education | 2003 |
| Mytime Enterprises Limited | Professional & scientific | 2003 |
| N M W Building Services Ltd | Construction | 2013 |
| N & T Property Management Limited | Real estate | 2018 |
| N Efanov Ltd | Information & communication | 2026 |
| N J Contracting Services Limited | Construction | 2025 |
| N M Waterproofing and Property Services Ltd | Construction | 2011 |
| N P Sargant Limited | Real estate | 2025 |
| N&A Grand Assets Ltd | Real estate | 2024 |
| N&A Interiors Ltd | Construction | 2019 |
| N&D Autocentre Limited | Wholesale & retail | 2026 |
| N2NRETAIL Limited | Wholesale & retail | 2024 |
| N3K London Limited | Manufacturing | 2022 |
| Naama Fitness and Wellness Limited | Health & social care | 2021 |
| Naata Limited | Information & communication | 2023 |
| Nadj Limited | Hospitality | 2018 |
| Naila Media Limited | Information & communication | 2022 |
| Nails and Hammers Limited | Manufacturing | 2025 |
| Naipunnya International Ltd | Administrative & support | 2018 |
| Namaste Kitchen (Falmouth) Limited | Hospitality | 2019 |
| Namrod Ltd | Professional & scientific | 2025 |
| Nanda and Sons Ltd | Wholesale & retail | 2022 |
| Nani Nani Ltd | Real estate | 2023 |
| NAO Group Ltd | Professional & scientific | 2024 |
| NAP Electrical Services Limited | Construction | 2025 |
| Napier Construction (South East) Limited | Construction | 1991 |
| Naqshara Limited | Wholesale & retail | 2025 |
| Narmos Ltd | Professional & scientific | 2025 |
| Nas-P Recycling Ltd | Wholesale & retail | 2020 |
| Nasa Infotech Limited | Information & communication | 2015 |
| Nash & Chaos Limited | Administrative & support | 2020 |
| Nash M&E Consulting Ltd | Professional & scientific | 2026 |
| Nashgre Ltd | Health & social care | 2011 |
| Natalie Enikeev Limited | Other services | 2012 |
| Natarandall Ltd | Arts & recreation | 2022 |
| National Contractor Network Ltd | Professional & scientific | 2018 |
| National Pump Services Limited | Other services | 2016 |
| National Trucking Ltd | Transport & logistics | 2019 |
| National Vehicle Movements Ltd | Transport & logistics | 2026 |
| Nationwide Fire Door Surveys Ltd | Public administration | 2021 |
| Natpro Limited | Wholesale & retail | 2019 |
| Natvinc Ltd | Wholesale & retail | 2013 |
| NAV Investments Ltd | Real estate | 2016 |
| Navaris Solutions Limited | Wholesale & retail | 2025 |
| Nayankruti Ltd | Information & communication | 2024 |
| Nayu UK Ltd | Wholesale & retail | 2025 |
| Nazz Legal Services Limited | Professional & scientific | 2022 |
| NB Brickwork & Construction Ltd | Construction | 2019 |
| NB Phlebotomy Ltd | Health & social care | 2025 |
| Nbnm Investments Limited | Real estate | 2020 |
| NC Contracts Limited | Administrative & support | 2014 |
| NCB Rail Planning Consultants Limited | Professional & scientific | 2023 |
| Neevii Limited | Information & communication | 2025 |
| Neilcott Construction Limited | Construction | 1973 |
| Neilcott Construction Services Limited | Professional & scientific | 1986 |
| Neilcott Developments Limited | Construction | 1967 |
| Neilcott EOT Limited | Administrative & support | 2021 |
| Neilcott Group Holdings Limited | Professional & scientific | 2012 |
| Neilcott Holdings Limited | Professional & scientific | 1986 |
| Nella Commercial Properties Limited | Real estate | 2017 |
| Nella Cutlery South Limited | Manufacturing | 2014 |
| Nella Holdings Limited | Professional & scientific | 2017 |
| Nella Limited | Manufacturing | 2005 |
| Nella Marine Limited | Transport & logistics | 2025 |
| Nella Properties Ltd | Professional & scientific | 2015 |
| Nella Property & Maintenance Limited | Real estate | 2016 |
| NEO 90 Limited | Information & communication | 2015 |
| Neon Effect Ltd | Wholesale & retail | 2020 |
| Neon Orange Limited | Professional & scientific | 2019 |
| Neptyune Ltd | Information & communication | 2026 |
| Nerveng Consulting Limited | Professional & scientific | 2018 |
| Nesta Solutions Ltd | Construction | 2007 |
| Nestura Trusted Ltd | Real estate | 2025 |
| Netflow Consulting Ltd | Construction | 2024 |
| Netnavi AI Ltd | Information & communication | 2026 |
| Netra Hospitality Ltd | Hospitality | 2026 |
| Netramani Housing Ltd | Real estate | 2024 |
| Nets & Comms Limited | Information & communication | 1997 |
| Netscafe Ltd | Hospitality | 2025 |
| Network Utilities (Systems) Limited | Information & communication | 1993 |
| Neuro London Ltd | Health & social care | 2016 |
| Neurolane Ltd | Professional & scientific | 2023 |
| Nevin & Sons Limited | Construction | 2016 |
| New Auraa Ltd | Health & social care | 2020 |
| New Balham Sushi Ltd | Wholesale & retail | 2017 |
| New Dawn Property Buyers Ltd | Real estate | 2018 |
| New Dawn Property Group UK Ltd | Real estate | 2022 |
| New ERA Energy Ltd | Construction | 2022 |
| New ERA Renewable Systems Ltd | Construction | 2025 |
| New ERA Renewables Ltd | Construction | 2022 |
| New European Distressed Donkey Initiative Ltd | Other services | 1995 |
| New Generation Creation Limited | Wholesale & retail | 2022 |
| New Indian Valley Limited | Hospitality | 2024 |
| New Level Barberz Ltd | Other services | 2018 |
| New Look Traders Ltd | Construction | 2017 |
| New Tudor Group LLP | | 2021 |
| New Wave Acad Ltd | Education | 2024 |
| Newberry's Painting & Decorating Limited | Construction | 2011 |
| Newfield Handmade Sandwiches Limited | Manufacturing | 2015 |