| MTK Locums Limited | Other services | 2018 |
| MTK Property Management Ltd | Real estate | 2023 |
| Muir Management Consultancy Ltd | Professional & scientific | 2014 |
| Muirkirk Caravan Park 2004 Limited | Hospitality | 2004 |
| Mulderrig Civil Consulting Ltd | Construction | 2026 |
| Mulloys Limited | Wholesale & retail | 2002 |
| Multi-Flow Dispense Ltd | Professional & scientific | 2023 |
| Multitool LAB Limited | Manufacturing | 2022 |
| Mumbai Cuisines Limited | Hospitality | 2010 |
| Munday Estates Limited | Real estate | 1999 |
| Munshi Asset Holdings Limited | Real estate | 2018 |
| Musaf Properties Ltd | Real estate | 2025 |
| Musafir Earby Ltd | Hospitality | 2017 |
| Musafir Holdings Ltd | Real estate | 2022 |
| Musicloud Limited | Other services | 2014 |
| MV Auto Solutions Limited | Wholesale & retail | 2018 |
| MVS Developments Limited | Construction | 2004 |
| MW Plant & Vehicle Repairs Ltd | Professional & scientific | 2025 |
| Mwst Holdings Limited | Wholesale & retail | 2026 |
| My Collection Limited | Professional & scientific | 2009 |
| My Perfect Stay Properties Ltd | Real estate | 2025 |
| My Properties Ltd | Real estate | 2007 |
| My Toy Shop Limited | Wholesale & retail | 2026 |
| Myhol Limited | Administrative & support | 2020 |
| Mylz Ltd | Manufacturing | 2026 |
| Mysmarttvs Limited | Wholesale & retail | 2017 |
| N & M Holdings Ltd | Real estate | 2024 |
| N & S Contractors Ltd | Construction | 2024 |
| N J Thornton DRY Stone Walling Ltd | Construction | 2026 |
| N R S Holdings Limited | Wholesale & retail | 1995 |
| N Squared Construction Limited | Extraterritorial | 2020 |
| N&L Sons Ltd | Construction | 2025 |
| N.A.C. Associates Limited | Construction | 1996 |
| NA Dent Ltd | Health & social care | 2023 |
| Nadia@Socialwork Limited | Health & social care | 2022 |
| NAH Consultancy Services Limited | Professional & scientific | 2013 |
| Namburi Ltd | Hospitality | 2025 |
| Nanjingshire Group Ltd | Real estate | 2026 |
| Nanocleanse UK Ltd | Wholesale & retail | 2025 |
| Nanomax Detailing Ltd | Wholesale & retail | 2018 |
| Nansel Import and Export Ltd | Manufacturing | 2023 |
| Napirei Holding Limited | Administrative & support | 1996 |
| National Business Solutions Ltd | Construction | 2014 |
| National Deliveries Ltd | Transport & logistics | 2023 |
| Nationwide Consultancy Services Limited | Professional & scientific | 2015 |
| Natural Edge Exotics Limited | Manufacturing | 2024 |
| Natural Edge Timber Limited | Manufacturing | 2024 |
| Natzolu Limited | Hospitality | 2012 |
| Nawazsons Ltd | Wholesale & retail | 2024 |
| Nawrolly Limited | Administrative & support | 2025 |
| Naylor-Smith Properties Limited | Real estate | 1931 |
| Nazam Builders Limited | Construction | 2022 |
| Nazm Estates Ltd | Real estate | 2026 |
| Nazm Holdings Ltd | Financial services | 2026 |
| NCS35 Limited | Wholesale & retail | 2024 |
| Ndidia Lounge & Cuisines Ltd | Hospitality | 2025 |
| NDM Car Care Ltd | Wholesale & retail | 2022 |
| Ndpl Management Limited | Wholesale & retail | 2015 |
| Neal Educational Associates Limited | Education | 2014 |
| Neat Products Limited | Manufacturing | 2002 |
| Nebula Girls Group CIC | Health & social care | 2024 |
| NED LET Limited | Wholesale & retail | 2005 |
| Neetpeople CIC | Health & social care | 2025 |
| Neil Shimmin Limited | Construction | 2014 |
| Neophix Clamp Company Limited | Manufacturing | 1999 |
| Neophix Engineering Co. Limited | Manufacturing | 1977 |
| Neowave UK Ltd | Wholesale & retail | 2024 |
| Nerdz Arcade Bar Ltd | Hospitality | 2023 |
| Nesfield Holdings Limited | Financial services | 2025 |
| Nesfield Properties Limited | Real estate | 2025 |
| Nessa Poultry Limited | Wholesale & retail | 2017 |
| Nessfield Property Holdings Limited | Real estate | 2025 |
| Nest EGG Capital & Property Lettings Ltd | Administrative & support | 2016 |
| Nesterra Design & Build Ltd | Construction | 2025 |
| Netherghyll Holdings Limited | Construction | 2016 |
| Network Infrastructure Build Limited | Construction | 2023 |
| Network Lifts Limited | Manufacturing | 2016 |
| Neurodiversify CIC | Administrative & support | 2025 |
| Neutrino Properties Ltd | Real estate | 2024 |
| New Chef's Keighley Ltd | Hospitality | 2025 |
| New Fabrications & Welding Limited | Manufacturing | 2023 |
| New Futures Counselling Ltd | Health & social care | 2021 |
| New Laithe Transport Ltd | Transport & logistics | 2018 |
| New Leaf Tree & Landscaping Care Ltd | Administrative & support | 2026 |
| New Life Financial Limited | Professional & scientific | 2017 |
| New ROW Cottage Estate Ltd | Households | 2025 |
| New Stone AGE Limited | Manufacturing | 1987 |
| Newall Aerospace Limited | Manufacturing | 2020 |
| Newbridge Keighley Limited | Real estate | 1996 |
| Newmark Developments (Yorkshire) Limited | Construction | 2022 |
| Newmark Electrical Limited | Construction | 2004 |
| News Cabin Limited | Wholesale & retail | 2020 |
| Nexaco Ltd | Wholesale & retail | 2025 |
| Nexgen Pest Control Ltd | Administrative & support | 2026 |
| Nexgen Property Ltd | Real estate | 2024 |
| Next GEN Psych Ltd | Health & social care | 2025 |
| Next Level Engineering Services Ltd | Professional & scientific | 2023 |
| Nextage Solutions Limited | Information & communication | 2018 |
| Nextgen Energy Homes Ltd | Professional & scientific | 2020 |
| Nexus Initiatives Ltd | Construction | 2025 |