| My Recruitment Career Limited | Administrative & support | 2023 |
| My Staff Direct Limited | Hospitality | 2020 |
| MYA Aesthetics for YOU Ltd | Health & social care | 2026 |
| MYA Group Ltd | Professional & scientific | 2017 |
| Mycophile Limited | Agriculture & fishing | 2026 |
| Mylifepool Ltd | Other services | 2020 |
| Mypetsitter Ltd | Information & communication | 2026 |
| Mypill Limited | Health & social care | 1960 |
| Myrings Estate Agents Ltd | Real estate | 2008 |
| Myroo Ltd | Manufacturing | 2016 |
| N & E Clarke & Sons Ltd | Transport & logistics | 2026 |
| N C Construction & Development Ltd | Construction | 2002 |
| N Dobson Limited | Professional & scientific | 2013 |
| N J Cape Ltd | Real estate | 2011 |
| N0RT Limited | Construction | 2022 |
| N1CKY Limited | Extraterritorial | 2020 |
| N1COLA Limited | Extraterritorial | 2020 |
| N1GEL Limited | Extraterritorial | 2020 |
| N1NA Ltd | Extraterritorial | 2022 |
| NAD1A Limited | Extraterritorial | 2020 |
| Nagaraj & Hayward Consultancy Ltd | Administrative & support | 2024 |
| Nahthen Estates Limited | Administrative & support | 2025 |
| Nail Craft Ltd | Extraterritorial | 2012 |
| Namaste Enterprises Limited | Extraterritorial | 2019 |
| Name Limited | Administrative & support | 2005 |
| Nandhra Property Group Ltd | Construction | 2025 |
| Naomi C Limited | Wholesale & retail | 2023 |
| Narey Financial Planning Ltd | Financial services | 2020 |
| Nasa Inc Ltd | Construction | 2019 |
| Nasmat Almmlakah Ltd | Wholesale & retail | 2024 |
| Nassar Trading Ltd | Wholesale & retail | 2022 |
| NATAL1E Limited | Extraterritorial | 2020 |
| Natalia Limited | Extraterritorial | 2020 |
| Natalie Eagling Consulting Ltd | Professional & scientific | 2022 |
| National Champion Limited | Extraterritorial | 2026 |
| National GAS & Aircon Limited | Construction | 2026 |
| National Housing Procurement Association Ltd | Professional & scientific | 2025 |
| Nations and Regions Limited | Extraterritorial | 2012 |
| Nationwide Property Management Limited | Households | 2008 |
| Natural Flair Limited | Professional & scientific | 1986 |
| Natural Healing Group Ltd | Wholesale & retail | 2022 |
| Natural Selection Talent Acquisition Ltd | Administrative & support | 2023 |
| Natural Stone Cleaning Ltd | Manufacturing | 2023 |
| Natural WAX Ltd | Extraterritorial | 2012 |
| Natures Little Learners Ltd | Health & social care | 2020 |
| Naught One Ltd | Manufacturing | 2004 |
| Naughtone (Holdings) Limited | Financial services | 2012 |
| Naughtone Manufacturing Ltd | Manufacturing | 2011 |
| Nautilus Transport Limited | Extraterritorial | 2021 |
| NAVIG8 Luxury Travel Ltd | Administrative & support | 2023 |
| Navigator FM Limited | Wholesale & retail | 2024 |
| Naviti Medical Ltd | Health & social care | 2002 |
| Naylor Asset Group Ltd | Real estate | 2025 |
| Nbrhd Studio Ltd | Professional & scientific | 2026 |
| NC Commercial Ltd | Administrative & support | 2013 |
| NC Property Rental Limited | Households | 2023 |
| NC Property Rental Solutions LLP | | 2026 |
| NDV Solutions Ltd | Information & communication | 2018 |
| NE (Portable) GAS Limited | Wholesale & retail | 2025 |
| NE GAS SW Limited | Wholesale & retail | 2025 |
| Neald Limited | Extraterritorial | 2025 |
| Neargoal Limited | Real estate | 1994 |
| Nebras Sudan General Contracting Ltd | Construction | 2024 |
| NEC Legal Consulting Limited | Professional & scientific | 2025 |
| Necta Limited | Extraterritorial | 2011 |
| Neil and Sonya Milsted Independent Funeral Directors Ltd | Other services | 2019 |
| Neil Donnelly Project Services Limited | Professional & scientific | 2017 |
| Neil Firth Services Ltd | Manufacturing | 2015 |
| Neil Hall & Sons Limited | Administrative & support | 2011 |
| Neil Mercer Property Limited | Real estate | 2021 |
| Neil Raistrick Ltd | Wholesale & retail | 2025 |
| Nellie's Trove Antique & Vintage Jewellery Limited | Wholesale & retail | 2021 |
| Nelson Medical Ltd | Manufacturing | 2019 |
| Neode Digital Limited | Information & communication | 2022 |
| Neomission Consult Ltd | Professional & scientific | 2023 |
| Neoss Limited | Manufacturing | 2000 |
| Neoss UK & Ireland Limited | Health & social care | 2022 |
| NEP (Yorkshire) Limited | Construction | 2024 |
| Nero Facilities Management Limited | Extraterritorial | 2020 |
| Nest EGG Property Group Ltd | Construction | 2021 |
| Nest Hub Holding Ltd | Extraterritorial | 2022 |
| Nest Hub Ltd | Real estate | 2019 |
| NET Create Limited | Information & communication | 2026 |
| NET Shopper Ltd | Extraterritorial | 2012 |
| NET Zero Inc Limited | Professional & scientific | 2025 |
| Network 2020 Limited | Professional & scientific | 2013 |
| Network Corner Ltd | Wholesale & retail | 2024 |
| Neugenera Ltd | Information & communication | 2026 |
| Neurodivergent Films Limited | Information & communication | 2022 |
| Neurology 4 U Limited | Health & social care | 2018 |
| Neurosmart Learning Limited | Professional & scientific | 2023 |
| New AGE Retro Ltd | Extraterritorial | 2012 |
| New Brompton Court Limited | Real estate | 1973 |
| New Business Limited | Extraterritorial | 2013 |
| New Chapter Talent Solutions Limited | Administrative & support | 2019 |
| New Cold Bath Deli Ltd | Hospitality | 2025 |
| New Collection by Leah Limited | Wholesale & retail | 2025 |
| New Horizon Global Ltd | Information & communication | 2022 |
| New Image TV (International) Limited | Wholesale & retail | 2008 |
| New Image TV (US) Limited | Wholesale & retail | 2008 |