| Motor City Sales Ltd | Wholesale & retail | 2019 |
| Motorworks Truck and Machinery Services Ltd | Wholesale & retail | 2019 |
| Mototune Limited | Wholesale & retail | 2009 |
| Mount Nebo Limited | Information & communication | 2015 |
| Moving Designs Limited | Construction | 2007 |
| Mrms Properties Ltd | Real estate | 2023 |
| MRN Cardiology Ltd | Health & social care | 2021 |
| MRN UK Properties Ltd | Real estate | 2026 |
| Mrscarters Ltd | Hospitality | 2022 |
| MS Innovation Ventures Ltd | Professional & scientific | 2022 |
| MS Motorcars Limited | Wholesale & retail | 2025 |
| MSC Property Services Ltd | Professional & scientific | 2015 |
| Mscadd Ltd | Professional & scientific | 2022 |
| MSL Legacy Limited | Real estate | 2018 |
| Msvv Ltd | Information & communication | 2017 |
| Mtech Consulting Ltd | Information & communication | 2025 |
| Mtech Thin Sections Limited | Professional & scientific | 2013 |
| MTF (International) Ltd | Wholesale & retail | 2016 |
| Mttc Ltd | Information & communication | 2012 |
| Munopoly Property Ltd | Real estate | 2019 |
| MUR Consultancy Ltd | Health & social care | 2017 |
| Murray Accountancy Services Limited | Professional & scientific | 2012 |
| Murray Creative Studio Ltd | Information & communication | 2026 |
| Musaics Ltd | Wholesale & retail | 2024 |
| MVH Building Services Limited | Construction | 2018 |
| Mvjc Business Consultancy Ltd | Professional & scientific | 2012 |
| MW Joinery & Services Ltd | Manufacturing | 2020 |
| MW Scenes Ltd | Manufacturing | 2023 |
| MWN Properties Ltd | Real estate | 2023 |
| My Chauffeur Limited | Professional & scientific | 2001 |
| My Jukes Ltd | Wholesale & retail | 2018 |
| My Local Garage Limited | Professional & scientific | 2007 |
| N & Sons Estates Limited | Real estate | 2025 |
| N G Craftsman Ltd | Manufacturing | 2012 |
| N. Fleming Plastering and Tiling Ltd | Construction | 2024 |
| Nafe Nails 2021 Ltd | Other services | 2024 |
| Najberg Milne Limited | Professional & scientific | 2012 |
| Nakad Ltd | Hospitality | 2025 |
| Nala’S Training Services Ltd | Other services | 2024 |
| Nama Partners Limited | Financial services | 2026 |
| Namo Global Enterprises Ltd | Real estate | 2019 |
| Napier Occupational Health Limited | Health & social care | 2023 |
| Nasa Comercial DE Nascimento Alberto UK Limited | Mining & quarrying | 2016 |
| Nashleigh House Limited | Households | 1985 |
| Natabi (HW) Properties Limited | Construction | 2021 |
| Natabi Blue Limited | Construction | 2016 |
| Natabi Fareham Care Limited | Construction | 2019 |
| Natabi Green Limited | Financial services | 2016 |
| Natabi Hildenborough Limited | Construction | 2019 |
| Natabi Properties Limited | Construction | 2013 |
| Natabi Properties Orpington Limited | Construction | 2018 |
| Natabi Properties Redhill Limited | Construction | 2018 |
| Natabi Rickmansworth Limited | Other services | 2014 |
| Natabi Weybridge Care Limited | Construction | 2024 |
| Natabi Wheatley Care Limited | Construction | 2021 |
| Natalia Zielinska Consulting Ltd | Professional & scientific | 2021 |
| Natalino Limited | Professional & scientific | 2025 |
| National Lock & Safe Limited | Extraterritorial | 2022 |
| Natkaj Limited | Professional & scientific | 2010 |
| Natternoise Ltd | Information & communication | 2014 |
| Natural Glow Limited | Wholesale & retail | 2021 |
| Natural Music Services Limited | Education | 2017 |
| Naylormade Holdings Limited | Real estate | 2021 |
| NBL Solutions Limited | Information & communication | 2021 |
| Negative Frame Productions Ltd | Information & communication | 2020 |
| Neil Poole Limited | Professional & scientific | 2024 |
| Nena Wholesale Bakery Ltd | Manufacturing | 2025 |
| Neochron Ltd | Information & communication | 2025 |
| NET Property Consultants Limited | Professional & scientific | 2006 |
| Network for Skills Investments Ltd | Real estate | 2019 |
| Network for Skills Limited | Professional & scientific | 2011 |
| Neuratek Ltd | Information & communication | 2006 |
| New King Street Management Limited | Households | 1994 |
| New Line Agencies Limited | Transport & logistics | 2001 |
| New Loss Prevention Limited | Professional & scientific | 2014 |
| New Town Cars Limited | Wholesale & retail | 2009 |
| New Wave of Classic Rock Ltd | Arts & recreation | 2022 |
| Newborough Health Ltd | Wholesale & retail | 2021 |
| Newman Ward Limited | Real estate | 1987 |
| Neworld Consultancy Limited | Professional & scientific | 2010 |
| Neworld Holdings Ltd | Real estate | 2019 |
| Newton Maxwell Recruitment Limited | Administrative & support | 2020 |
| Newtown Motor Company Ltd | Wholesale & retail | 2014 |
| Nexa Investments Ltd | Real estate | 2025 |
| Nexgen Insights Ltd | Information & communication | 2024 |
| Nextgen Fleet Limited | Transport & logistics | 2019 |
| Nextgen UK Holdings Limited | Financial services | 2018 |
| NFB Properties Ltd | Real estate | 2024 |
| Nicholas Cowan Ltd | Health & social care | 2011 |
| Nicmar Limited | Construction | 2023 |
| Nida Medical Services Limited | Health & social care | 2025 |
| Nigel Lawrence Limited | Real estate | 1990 |
| Night Owls (UK) Ltd | Administrative & support | 2013 |
| Nilesh DE Silva Limited | Professional & scientific | 2020 |
| Nimmo Project Consulting Limited | Professional & scientific | 2013 |
| Niranshi Ltd | Real estate | 2026 |
| NJ Management Consultancy Limited | Information & communication | 2015 |
| NJB Sparks Ltd | Construction | 2021 |
| NL Care & Senior Living Property Limited | Extraterritorial | 2018 |
| NL Care Developments Limited | Construction | 2021 |