| MIA Bailey Consultancy Ltd | Professional & scientific | 2021 |
| MIA Elite Chauffeurs Limited | Transport & logistics | 2023 |
| Miami Vibe 305 Limited | Wholesale & retail | 2026 |
| MIB Serrvices Ltd | Real estate | 2026 |
| Micebook Limited | Information & communication | 2014 |
| Midas, Morgan and Maecenas Ltd | Financial services | 2020 |
| Mike Slater Consulting Limited | Professional & scientific | 2025 |
| Mikproud (Holloway) Limited | Real estate | 2016 |
| Mikproud (Old Park Farm) Limited | Construction | 2016 |
| Mikproud Assets Limited | Financial services | 2000 |
| Mikproud Management Limited | Real estate | 2024 |
| Mirakel Limited | Information & communication | 2008 |
| Mirand Couriers Limited | Transport & logistics | 2025 |
| Mirand Logistics Ltd | Transport & logistics | 2022 |
| MJ Chauffeurs Ltd | Transport & logistics | 2025 |
| MJG Ornate Plasterworks Limited | Construction | 2025 |
| MJQ Limited | Administrative & support | 1997 |
| MK Journey’S Limited | Administrative & support | 2026 |
| MK Tiles Warehouse Ltd | Wholesale & retail | 2023 |
| MML Chauffeur Services Ltd | Transport & logistics | 2025 |
| MNS Fabrics Limited | Wholesale & retail | 2025 |
| Mobion Limited | Information & communication | 2025 |
| Moda Design Studio Ltd | Professional & scientific | 2023 |
| Moni Property Investments Ltd | Extraterritorial | 2004 |
| Monico Investments Limited | Professional & scientific | 1993 |
| Montotte Property Services Ltd | Construction | 2013 |
| Morley’S & More Ltd | Construction | 2025 |
| Mosgef Limited | Extraterritorial | 2015 |
| MP Tree Limited | Real estate | 2023 |
| MTC Admin Limited | Administrative & support | 2023 |
| MTK MED Ltd | Health & social care | 2019 |
| MTP Digital Limited | Information & communication | 2025 |
| Mulberry Office Solutions Ltd | Administrative & support | 2024 |
| Mutable Films Ltd | Information & communication | 2021 |
| My Eco Energy Ltd | Information & communication | 2023 |
| My Envoy Limited | Professional & scientific | 2013 |
| My Golf Guest Limited | Wholesale & retail | 2021 |
| My Investment Capital Limited | Real estate | 2017 |
| My Investments (London) Limited | Real estate | 2016 |
| My Outhouse Limited | Manufacturing | 2021 |
| N & a Hospitality Limited | Hospitality | 2025 |
| N 1 Chauffeurs Ltd | Transport & logistics | 2025 |
| Nadiri Ltd | Other services | 2017 |
| Namhong Limited | Wholesale & retail | 2022 |
| Navigate the Maze Limited | Professional & scientific | 2024 |
| Ncpp (Two) Limited | Real estate | 2024 |
| Ndft Consultancy Limited | Information & communication | 1995 |
| Nechasim Limited | Real estate | 2024 |
| Neesan Limited | Real estate | 2023 |
| Nelbar &Co Limited | Transport & logistics | 2025 |
| Ness M Care Services Ltd | Health & social care | 2009 |
| Neto Limited | Real estate | 2000 |
| Netware BVI Limited | Wholesale & retail | 2024 |
| Neuroinformed Services Ltd | Education | 2026 |
| New Life New Licence Ltd | Administrative & support | 2025 |
| New Media INK Limited | Information & communication | 2025 |
| Newcity Property Partners Limited | Real estate | 2016 |
| Newton Military Recruitment Limited | Administrative & support | 2026 |
| Next Step Corporate Ltd | Construction | 2025 |
| Nick Greenston Consulting Ltd | Professional & scientific | 2024 |
| Nick K Fibre Design Ltd | Professional & scientific | 2021 |
| Nightingale Close Management Company Limited | Households | 1990 |
| Nightwing Consulting Ltd | Professional & scientific | 2014 |
| Nikadoshar Ltd | Real estate | 2025 |
| Nitro Theory Limited | Information & communication | 2025 |
| Nivas Estates Ltd | Real estate | 2025 |
| NMM Capital Ltd | Financial services | 2024 |
| NO. 38 Watling Street Ltd. | Health & social care | 2022 |
| Noblehill Limited | Construction | 1997 |
| Nolan Brothers (I) Limited | Financial services | 2025 |
| Nolan Brothers (II) Limited | Construction | 2026 |
| Nolan Brothers Properties Limited | Construction | 2014 |
| North England Football Club Limited | Arts & recreation | 2024 |
| Noshers of Stanmore Limited | Hospitality | 2020 |
| Noshers of Totteridge Limited | Wholesale & retail | 2016 |
| Novowash Limited | Administrative & support | 2022 |
| Numabs Ltd | Professional & scientific | 2019 |
| Nuuvo Ltd | Health & social care | 2024 |
| O'Shea Surveying Services Limited | Professional & scientific | 2017 |
| O.H. Baldock Property Limited | Real estate | 2025 |
| O.W.H.L Ltd | Information & communication | 2023 |
| Oak Tree Mews Management Limited | Households | 2011 |
| Oakridge Avenue Limited | Other services | 2007 |
| Oakridge Management Services Limited | Professional & scientific | 1997 |
| Oaks Close (Management) Limited | Households | 1989 |
| Oasis Childrens Home Limited | Health & social care | 2025 |
| Oban CNC Ltd | Manufacturing | 2020 |
| Ocean Cloud Limited | Information & communication | 2013 |
| OCO Builders UK Limited | Construction | 2013 |
| Odeliaz Productions Ltd | Information & communication | 2026 |
| OJD Enterprises and Consultants Limited | Professional & scientific | 2016 |
| Old Town Property Limited | Real estate | 2013 |
| Olive Natural Health Limited | Wholesale & retail | 2010 |
| Olympyx Limited | Wholesale & retail | 1992 |
| One Stop Property Hub Limited | Construction | 2019 |
| One Vision Eyecare Ltd | Health & social care | 2006 |
| Onescan Limited | Administrative & support | 2023 |
| Optimal Wealth Management Limited | Professional & scientific | 2020 |
| Optimyse Nutrition Ltd | Professional & scientific | 2022 |
| Opulence Executive Cars Ltd | Transport & logistics | 2024 |