| Msktech Limited | Information & communication | 2012 |
| MT Consulting & Brokerage, Ltd. | Wholesale & retail | 2018 |
| Mudher Construction Ltd | Other services | 2016 |
| Mufs Consultants Limited | Information & communication | 2005 |
| Mullan Consultants Ltd | Information & communication | 2009 |
| Mullberry Contractors Limited | Construction | 2012 |
| Mulroy Hotels (London) Limited | Hospitality | 1987 |
| Multicom Business Systems Limited | Information & communication | 1992 |
| Multilingual Wellbeing Services | Health & social care | 2010 |
| Munde Construction Limited | Construction | 2006 |
| Munden Limited | Professional & scientific | 1993 |
| Muneer Contracting Limited | Information & communication | 2006 |
| Muni-Serve (Bedford) Limited | Real estate | 1971 |
| Murad Capital Limited | Wholesale & retail | 2009 |
| Murborough Limited | | 1977 |
| Murdoch & Powell Limited | Arts & recreation | 2015 |
| Murray Makes Limited | Arts & recreation | 2006 |
| Musical Minis Limited | Administrative & support | 1993 |
| Musical Queertre Ltd | Arts & recreation | 2025 |
| Musikzone (Wembley) Limited | Information & communication | 2007 |
| Mustard Music Publishing Limited | Information & communication | 2003 |
| MVP Carpentry Ltd | Construction | 2018 |
| My Own Media Limited | Professional & scientific | 2007 |
| My Own Space Limited | Real estate | 2017 |
| My Prestige Accountant Ltd | Professional & scientific | 2012 |
| My Prestige Accounting Training Ltd | Education | 2025 |
| My Workspace Weyhill Ltd | Real estate | 2018 |
| Mybrandtruth Ltd | Professional & scientific | 2016 |
| Myrtleside Residents Association Limited | Households | 1981 |
| Mythical Worlds Limited | Administrative & support | 2018 |
| Myuniverstyabroad Limited | Information & communication | 2024 |
| Myzak Limited | Real estate | 2003 |
| N K Enterprises Ltd | Wholesale & retail | 1999 |
| N Kays Limited | Wholesale & retail | 2002 |
| N V Patel Construction Ltd | Real estate | 2003 |
| N&D Contractors Ltd | Construction | 2023 |
| N.A.S.Hart & Co Limited | Wholesale & retail | 1951 |
| N.G.N. Trading Co Limited | Transport & logistics | 1983 |
| N.W. Plant Hire Limited | Construction | 2003 |
| Nada Nurturing Support and Services Ltd | Health & social care | 2025 |
| Nadali Limited | Health & social care | 2004 |
| Nagamma Limited | Wholesale & retail | 2020 |
| Naiya Ltd | Professional & scientific | 2011 |
| Namaste Kitchen Restaurant Ltd | Hospitality | 2025 |
| Nandra Properties Limited | Real estate | 2004 |
| NAR Associates Ltd | Wholesale & retail | 2007 |
| Nari Business Psychologists Limited | Health & social care | 2005 |
| Narrow Boat Trust Limited(The) | Transport & logistics | 1983 |
| Nash Chauffeurs Limited | Transport & logistics | 2007 |
| Nash Solutions Limited | Professional & scientific | 2003 |
| National Solus Sites Limited | Professional & scientific | 1935 |
| Nationwide Maintenance Services Ltd | Construction | 2017 |
| Naturally Best Limited | Wholesale & retail | 2001 |
| Nautical Supply International Limited | Administrative & support | 2003 |
| Nauticalia Limited | Wholesale & retail | 1988 |
| Navehtek Limited | Information & communication | 2006 |
| Navtex Consulting Limited | Information & communication | 2013 |
| Nayish Limited | Construction | 2017 |
| NBS Sports Ltd | Arts & recreation | 2016 |
| NC Financial Solutions Limited | Professional & scientific | 2006 |
| ND Smart Build Ltd | Construction | 2021 |
| Negarestan Limited | Construction | 2004 |
| Nemedia Holdings Limited | Information & communication | 2026 |
| Neopet Properties Limited | Real estate | 2025 |
| Neseta Flat Management Limited | Real estate | 1995 |
| Netbase Limited | Information & communication | 2024 |
| Netetiquette Ltd | Information & communication | 2002 |
| Netheat Limited | Construction | 2015 |
| Neuro Physio Pro Limited | Health & social care | 2018 |
| Neuron Healthcare Limited | Health & social care | 2022 |
| Nevisoft Limited | Information & communication | 2003 |
| New Asian Tandoori Centre Limited | Hospitality | 1998 |
| New City Print Limited | Administrative & support | 2006 |
| New Fame Foods Limited | Hospitality | 2006 |
| New Housebox Ltd | Other services | 2008 |
| New Ritz Herbals Limited | Other services | 2018 |
| New Springwell VEG Ltd | Wholesale & retail | 2010 |
| New Unique Hair Ltd | Other services | 2023 |
| New White Horse Ltd | Hospitality | 2025 |
| New World Consultancy Limited | Administrative & support | 2001 |
| Newheight Accountancy Ltd | Professional & scientific | 2000 |
| Newlawns Limited | Professional & scientific | 2003 |
| Newport UK Limited | Manufacturing | 2001 |
| Newstar Trading Limited | Transport & logistics | 1981 |
| Newton Care Homes Limited | Health & social care | 2005 |
| Newvalley Homes Limited | Real estate | 2000 |
| Nexalpha Limited | Professional & scientific | 2005 |
| Nexan Estates Limited | Administrative & support | 1997 |
| Next Slim Thing Ltd | Wholesale & retail | 2014 |
| NHB Care Limited | Other services | 2005 |
| Nicholas Biddulph Business Services Limited | Financial services | 2002 |
| Nicholas. Mcnamara | | 1998 |
| Nick Archer & Jenny Pockley Limited | Arts & recreation | 2006 |
| Nick Jenkins Associates Limited | Education | 2005 |
| Nico (UK) Limited | Real estate | 1998 |
| Nico 2000 Limited | Manufacturing | 1999 |
| Nigon Trading Limited | Other services | 2016 |
| Nikhil Properties Ltd | Real estate | 2016 |
| Niko DS Ltd | Construction | 2004 |
| Nila Clinic Limited | Other services | 2026 |