| MSPEEDKENT69 Ltd | Transport & logistics | 2023 |
| MSR Food Services Ltd | Hospitality | 2024 |
| Mstc Limited | Real estate | 2025 |
| MT Bello Ltd | Health & social care | 2023 |
| Mtoto Ltd | Information & communication | 2020 |
| Mtsj Properties Limited | Real estate | 2024 |
| MTY Digital Ltd | Professional & scientific | 2025 |
| MTY Group Ltd | Construction | 2023 |
| Mughal Associates Ltd | Construction | 2024 |
| Mulberry Enterprises Kent Limited | Construction | 2013 |
| Multi Group 93 Ltd | Administrative & support | 2025 |
| Multi Hoses Limited | Wholesale & retail | 2024 |
| Multi Mechanics South East Limited | Wholesale & retail | 2023 |
| Multi Tyres Limited | Wholesale & retail | 2024 |
| Multilay Utilities S E Limited | Construction | 2024 |
| Multiple Choice Accountancy Ltd | Professional & scientific | 2012 |
| Multiplepairs Ltd | Wholesale & retail | 2021 |
| Mum's Thai Ltd | Wholesale & retail | 2024 |
| Muneethai Ltd | Other services | 2020 |
| Munn Engineering Ltd | Manufacturing | 2015 |
| Muolashi Ltd | Other services | 2017 |
| Mupani Properties Ltd | Real estate | 2025 |
| Murdoch Offshore PTE Limited | Professional & scientific | 2022 |
| Murfet Ltd | Real estate | 1997 |
| Musgrave Property Services Limited | Households | 2024 |
| Mustard Resource Services Ltd | Health & social care | 2011 |
| Muttley Creative Solutions Limited | Other services | 2016 |
| Muzech Technologies Ltd | Information & communication | 2025 |
| MV Heating and Plumbing Ltd | Construction | 2020 |
| MVM Ahead Ltd | Transport & logistics | 2022 |
| MVM Homes Limited | Real estate | 2025 |
| MVS Change Management Ltd | Professional & scientific | 2020 |
| MW Building Specialists Ltd | Construction | 2012 |
| MW Professional Services Limited | Information & communication | 2024 |
| MW Roofing Contractors Limited | Construction | 2025 |
| MWC Electrical Ltd | Professional & scientific | 2021 |
| MWC Mechanical Services Ltd | Construction | 2022 |
| MWC Metalcraft Ltd | Manufacturing | 2020 |
| MXX Limited | Construction | 2025 |
| My Floorspace Ltd | Construction | 2025 |
| My Interiorspace Ltd | Construction | 2025 |
| My Location Homes Ltd | Financial services | 2022 |
| My Pet Care Limited | Professional & scientific | 2017 |
| My Sleepover Party Ltd | Other services | 2019 |
| My Support Myway Limited | Health & social care | 2023 |
| My Tots Ltd | Health & social care | 2026 |
| My VA Everyday Ltd | Administrative & support | 2023 |
| Mycare Group Limited | Health & social care | 2023 |
| Mycare Myway Limited | Health & social care | 2023 |
| Myhand Cleaning Services Ltd | Administrative & support | 2026 |
| Mykhas (R&D) Consulting Limited | Administrative & support | 2013 |
| Mylandscapes Limited | Professional & scientific | 2003 |
| Mymedicalbank Ltd | Information & communication | 2014 |
| Myra Cole Legacy Ltd | Other services | 2025 |
| MZB Consulting Ltd | Extraterritorial | 2018 |
| N & a Property Management Limited | Real estate | 2021 |
| N & D Harris Limited | Construction | 2014 |
| N Farr Services Limited | Construction | 2022 |
| N Krishna Ltd | Health & social care | 2024 |
| N S Commercial South Limited | Real estate | 2021 |
| N&A Building Envelope Solutions Ltd | Construction | 2026 |
| N&E Ltd | Transport & logistics | 2025 |
| N.A.P Stays Ltd | Real estate | 2026 |
| N.O. Electrical 24/7 Ltd | Construction | 2021 |
| N.Tandy Roofing Limited | Construction | 2014 |
| N2 Research and Analytics Limited | Professional & scientific | 2024 |
| NAB Group Ltd | Construction | 2022 |
| Nabu Media Limited | Information & communication | 2010 |
| Nadem Ltd | Hospitality | 2025 |
| Naff Properties Ltd | Real estate | 2025 |
| Nagehan Ltd | Wholesale & retail | 2026 |
| Nahro Express Ltd | Wholesale & retail | 2025 |
| Naija Eats Limited | Information & communication | 2026 |
| Nail IT FIX IT Ltd | Information & communication | 2022 |
| Nail Naturally Ltd | Other services | 2023 |
| Nail Sense Ltd | Other services | 2018 |
| Nam's Care Ltd | Health & social care | 2019 |
| Namastay Holdings Ltd | Real estate | 2023 |
| Nanna Kay's Limited | Hospitality | 2018 |
| Nanosoft Technologies Ltd | Information & communication | 2023 |
| Naomi Calming Hands | Other services | 2025 |
| Napoleon Cruz Limited | Public administration | 2022 |
| Narmico Consulting Services Ltd | Information & communication | 2020 |
| Nashru Limited | Health & social care | 2022 |
| Natasha Global Ltd | Extraterritorial | 2018 |
| Natel Ltd | Construction | 2013 |
| Nationwide Group of Companies Limited | Professional & scientific | 2015 |
| Nationwide Servicing Ltd | Manufacturing | 2018 |
| Natmatcyn Limited | Real estate | 2016 |
| Natnat Limited | Professional & scientific | 2009 |
| Naturaestica Ltd | Wholesale & retail | 2012 |
| Naturalbeautymedway Ltd | Other services | 2026 |
| Naturally Cakes Ltd | Manufacturing | 2021 |
| Naumeniuk Skincare Team Ltd | Health & social care | 2023 |
| Navami Limited | Health & social care | 2024 |
| Naveen Resort Wear Ltd | Wholesale & retail | 2024 |
| Navergus Limited | Professional & scientific | 2018 |
| Navigator Productions Limited | Professional & scientific | 1994 |
| Naybec Construction Limited | Construction | 1997 |
| Nazar Kent Limited | Hospitality | 2019 |