| Naskam Property Limited | Construction | 2025 |
| Nasko 1981 Ltd | Transport & logistics | 2022 |
| Naspropertyrentals Ltd | Real estate | 2021 |
| Nasquire Limited | Administrative & support | 2022 |
| Nasri Cleaning Ltd | Administrative & support | 2024 |
| Nasty FOX Tattoo Ltd | Arts & recreation | 2022 |
| Natalie Brereton Consultancy Ltd | Professional & scientific | 2024 |
| Natalie Burns Digital Ltd | Professional & scientific | 2023 |
| Natalie Player Ltd | Professional & scientific | 2026 |
| Nataly Express Delivery Limited | Transport & logistics | 2015 |
| Natasha Health Care Ltd | Health & social care | 2022 |
| Natasha Osgood Chiropractic Ltd | Health & social care | 2021 |
| Natasha Quick Limited | Professional & scientific | 2020 |
| Natasha Rawlins Mortgages Ltd | Professional & scientific | 2019 |
| Nateflow Logistics Ltd | Wholesale & retail | 2024 |
| Nathan Catt Limited | Real estate | 2013 |
| Nathan Filer Ltd | Arts & recreation | 2012 |
| Nathan Harper Limited | Other services | 2016 |
| Nathan Harrison Media Ltd | Information & communication | 2013 |
| Nathan Horn Media Limited | Information & communication | 2025 |
| Nathan James Estate Agents Limited | Real estate | 2011 |
| Nathan Littleboy Property Ltd | Real estate | 2021 |
| Nathan Patel Creative Limited | Information & communication | 2017 |
| Nathan Property & Estate Developments Ltd | Real estate | 2025 |
| Nathan Wong Development Limited | Information & communication | 2013 |
| Natine Fragrances Ltd | Manufacturing | 2025 |
| Nation Autos Mechanics Ltd | Wholesale & retail | 2016 |
| Nation Housing Limited | Real estate | 2017 |
| Nation Market Limited | Wholesale & retail | 2023 |
| Nation Real Estate Limited | Real estate | 2006 |
| National Air Conditioning Ltd | Energy | 2025 |
| National Association of Teleworkers | Other services | 1992 |
| National Badge Ltd | Manufacturing | 2023 |
| National Burial Council CIC | Other services | 2023 |
| National Centre for Integrative Medicine Community Interest Company | Health & social care | 2013 |
| National Children's Orchestras of Great Britain | Health & social care | 1990 |
| National College for Logistics Ltd | Education | 2025 |
| National Freight Corporation Limited | Transport & logistics | 2023 |
| National Friendly Financial Solutions Limited | Financial services | 2005 |
| National Friendly Software Solutions Limited | Administrative & support | 2005 |
| National Grid Electricity Distribution (East Midlands) PLC | Energy | 1989 |
| National Grid Electricity Distribution (South Wales) PLC | Energy | 1989 |
| National Grid Electricity Distribution (South West) PLC | Energy | 1989 |
| National Grid Electricity Distribution (West Midlands) PLC | Energy | 1998 |
| National Grid Electricity Distribution Generation Limited | Energy | 1987 |
| National Grid Electricity Distribution Holdings Limited | Financial services | 2017 |
| National Grid Electricity Distribution Investments Limited | Professional & scientific | 1987 |
| National Grid Electricity Distribution Midlands Limited | Financial services | 1989 |
| National Grid Electricity Distribution Network Holdings Limited | Professional & scientific | 2014 |
| National Grid Electricity Distribution PLC | Energy | 2014 |
| National Grid Electricity Distribution Property Investments Limited | Real estate | 1989 |
| National Grid Helicopters Limited | Administrative & support | 1989 |
| National Grid Telecoms Limited | Information & communication | 1989 |
| National Law Associates LLP | | 2017 |
| National Next of KIN Register Limited | Administrative & support | 2024 |
| National Pest Solutions Ltd | Administrative & support | 2024 |
| National Project Services Ltd | Construction | 2025 |
| National Skills Academy for Logistics Limited | Education | 2019 |
| National Universities Padel League Limited | Arts & recreation | 2024 |
| National Vehicle Trading Ltd | Wholesale & retail | 2023 |
| Nationplus Healthcare Ltd | Health & social care | 2026 |
| Nationwide Breakdown Assistance Limited | Wholesale & retail | 2025 |
| Nationwide Car Assistance Limited | Extraterritorial | 2013 |
| Nationwide Chemical Assistance Limited | Administrative & support | 2014 |
| Nationwide Commercial Assistance Ltd | Extraterritorial | 2011 |
| Nationwide Fleet Assistance Limited | Administrative & support | 2014 |
| Nationwide Flood Assistance Limited | Extraterritorial | 2014 |
| Nationwide Logistics Assistance Limited | Transport & logistics | 2016 |
| Nationwide Motorbike Assistance Limited | Extraterritorial | 2012 |
| Nationwide Recruitment Assistance Limited | Administrative & support | 2016 |
| Nationwide Vehicle Assistance Limited | Extraterritorial | 2013 |
| Native Pilates Ltd | Arts & recreation | 2026 |
| Native Vine Bristol Limited | Hospitality | 2025 |
| Natra Studios Ltd | Manufacturing | 2024 |
| Natracare EOT Limited | Administrative & support | 2026 |
| Natsura Ltd | Information & communication | 2025 |
| Nattc Ltd | Education | 2022 |
| Natter Communications Limited | Professional & scientific | 2013 |
| Natty LAB Active Ltd | Wholesale & retail | 2020 |
| Natural Academy C.I.C. | Health & social care | 2008 |
| Natural Born Flooring Limited | Construction | 2010 |
| Natural Choice Nurseries Ltd. | Education | 2005 |
| Natural Christmas Tree Company Limited | Wholesale & retail | 2018 |
| Natural Coast Seafoods Limited | Manufacturing | 2018 |
| Natural Developments Limited | | 1990 |
| Natural Genius Limited | Health & social care | 2018 |
| Natural Health Developments Ltd | Health & social care | 2024 |
| Natural Media Limited | Information & communication | 2012 |
| Natural Nation Ltd | Wholesale & retail | 2020 |
| Natural Networks Community Interest Company | Education | 2024 |
| Natural Patina Limited | Information & communication | 2016 |
| Natural Perception Limited | Health & social care | 2014 |
| Natural Roof Ltd | Administrative & support | 2025 |
| Natural Screen Company Ltd | Extraterritorial | 2024 |
| Natural Stone and Lime Supplies Ltd | Manufacturing | 2024 |
| Natural Talent Services Limited | Professional & scientific | 2003 |
| Natural Treats Ltd | Wholesale & retail | 2020 |
| Natural VET Nutrition Limited | Extraterritorial | 2021 |
| Naturally HR Ltd | Professional & scientific | 2007 |
| Naturally in Tune Ltd | Construction | 2018 |