| MS IT Solutions Limited | Information & communication | 2006 |
| MSA IT Consultancy Limited | Information & communication | 2023 |
| MSB Biomotion Consulting Limited | Professional & scientific | 2024 |
| MSC LGR LLP | | 2021 |
| MSC MNT LLP | | 2021 |
| MSC SLT LLP | | 2021 |
| MSH9 Consulting Limited | Professional & scientific | 2025 |
| Msuk Franchising Ltd | Other services | 2022 |
| Mtek Electrical Services Limited | Construction | 2023 |
| MTG Building Services Limited | Construction | 2010 |
| Mtsp Limited | Health & social care | 2024 |
| MTX Nine Limited | Professional & scientific | 2019 |
| Muik Performance Ltd | Arts & recreation | 2024 |
| Mujika Limited | Administrative & support | 2016 |
| Mullany's Coaches (UK) Limited | Financial services | 2011 |
| Mullany's Coaches Limited | Transport & logistics | 2001 |
| Multi Plastic Fabrications Limited | Manufacturing | 2013 |
| Multiply Finance Limited | Financial services | 2020 |
| Munch'Inn Ltd | Hospitality | 2026 |
| Munday Properties Limited | Real estate | 2009 |
| Mundwic Limited | Professional & scientific | 2026 |
| Munro Studio Limited | Professional & scientific | 2010 |
| Muraligarments Ltd | Manufacturing | 2025 |
| Murbay Ltd | Hospitality | 2022 |
| Murganoz Ltd | Hospitality | 2025 |
| Murphy Boxing Ltd | Education | 2021 |
| Murray Heating & Plumbing Services Ltd | Construction | 2024 |
| Murray of Parton Limited | Hospitality | 2025 |
| Music Touring Ltd | Administrative & support | 2023 |
| Must ST a Limited | Hospitality | 2018 |
| Mutatio Ltd | Information & communication | 2015 |
| Mute Solutions Ltd | Hospitality | 2016 |
| Muttimoo Ltd | Transport & logistics | 2020 |
| MVJ61 Advisory Limited | Professional & scientific | 2023 |
| MWG Developments Limited | Construction | 2024 |
| MWJ Trading Ltd | Wholesale & retail | 2012 |
| My Autohouse Limited | Wholesale & retail | 2013 |
| My Bar Accountant Limited | Professional & scientific | 2015 |
| My Bloc Ltd | Manufacturing | 2026 |
| My Build Ally Ltd | Construction | 2026 |
| My Chemistry Tutor Ltd | Education | 2021 |
| My Connect Group Ltd | Professional & scientific | 2025 |
| My Home Designed Ltd | Professional & scientific | 2022 |
| My Magellan Limited | Other services | 2005 |
| My Medipedi Ltd | Wholesale & retail | 2021 |
| My Patience IS UN- Limited | Health & social care | 2025 |
| My Unique Place Ltd | Real estate | 2021 |
| My Word Communications Limited | Professional & scientific | 2010 |
| Mybooth Limited | Professional & scientific | 2011 |
| Mybusinessmentor Ltd | Professional & scientific | 2025 |
| Mykonos Bakery Ltd | Wholesale & retail | 2025 |
| Myland Construction Limited | Construction | 2019 |
| Myvetting.Com Ltd | Administrative & support | 2022 |
| MZ DOT Productions Limited | Arts & recreation | 2022 |
| Mzcr Ltd | Wholesale & retail | 2026 |
| MZM Fashion Services Ltd | Administrative & support | 2022 |
| MZP Events Limited | Professional & scientific | 2023 |
| MZZ International Ltd | Wholesale & retail | 2023 |
| N & S Property Investments Limited | Real estate | 2007 |
| N a J Property Solutions Ltd | Real estate | 2021 |
| N Paton Consultancy Limited | Professional & scientific | 2021 |
| N&D Foods Limited | Hospitality | 2024 |
| N10 Construction Limited | Construction | 2016 |
| Nabco Direct Limited | Wholesale & retail | 2003 |
| Nabco Group Limited | Wholesale & retail | 2008 |
| Nabco Sales Limited | Wholesale & retail | 2006 |
| NAC Industrial Ltd | Administrative & support | 2013 |
| Nadra Cardine Consulting Ltd | Professional & scientific | 2011 |
| Naidoo Holdings Limited | Wholesale & retail | 2025 |
| Nail Media Limited | Administrative & support | 2025 |
| Nails of Luxury Limited | Other services | 2024 |
| Naive Productions Limited | Wholesale & retail | 2019 |
| Naka Engineering Services Ltd. | Construction | 2014 |
| Naked Flame RUM Limited | Wholesale & retail | 2026 |
| Nali Homes Ltd | Households | 2025 |
| Nana Osei Ltd | Real estate | 2017 |
| Napcon Limited | Professional & scientific | 2023 |
| Napkin Group Limited | Financial services | 2016 |
| Napsbury Preservation Ltd | Households | 2021 |
| Narada Europe (UK) Ltd | Wholesale & retail | 2007 |
| Narasingha Ltd | Health & social care | 2021 |
| NAS Collective Ltd | Wholesale & retail | 2025 |
| Nat-Gen Solar 1 Limited | Energy | 2011 |
| Natallia Medical Limited | Health & social care | 2016 |
| Natchy Ltd | Wholesale & retail | 2018 |
| Natgas Ltd | Professional & scientific | 2023 |
| Nathan Riley Co. Limited | Other services | 2025 |
| Nathan Sage Limited | Professional & scientific | 2014 |
| Natrove Ltd | Wholesale & retail | 2025 |
| Natura Luxe Limited | Wholesale & retail | 2023 |
| Naturalize Ltd | Other services | 2012 |
| Naughty BOY Studio Limited | Manufacturing | 2006 |
| Nayagam Limited | Health & social care | 2019 |
| Nazoemi AM Ltd | Real estate | 2021 |
| Nazoemi Ltd | Professional & scientific | 2018 |
| NB Stores Ltd | Wholesale & retail | 2021 |
| Nbap Ltd | Wholesale & retail | 2024 |
| Nbcomms Limited | Professional & scientific | 2015 |
| NBF Focus Limited | Professional & scientific | 2012 |
| NE Consulting Services Limited | Professional & scientific | 2016 |