| MSA Capital Ltd | Construction | 2024 |
| Msmulkys Service Ltd | Administrative & support | 2017 |
| MSO Logistics Ltd | Transport & logistics | 2018 |
| MU Zeta Alpha Ltd | Professional & scientific | 2019 |
| Mudric Ltd | Information & communication | 2022 |
| Mugen Holdings Ltd | Financial services | 2025 |
| Mugen Tech Consulting Ltd | Professional & scientific | 2022 |
| Muhandis Lahori Ltd | Real estate | 2021 |
| Mujassar Enterprise Ltd | Real estate | 2024 |
| Mukhawar London Ltd | Wholesale & retail | 2025 |
| Mukta Holdings Ltd | Real estate | 2021 |
| Mulligans Golf Limited | Arts & recreation | 2025 |
| Munch & Bunch Ltd | Hospitality | 2024 |
| My Workforce Buddy Ltd | Professional & scientific | 2020 |
| My'Ammour Limited | Other services | 2021 |
| Myers FIX Ltd | Construction | 2026 |
| Myma Services Ltd | Real estate | 2018 |
| Nadesan Investments Limited | Real estate | 2024 |
| Naim Holdings Limited | Financial services | 2021 |
| Najam Capital Ltd | Financial services | 2025 |
| Nakisa Projects Ltd | Professional & scientific | 2011 |
| Nala Restaurant Ltd | Hospitality | 2025 |
| Nala Restaurant Redhill Ltd | Hospitality | 2026 |
| Namaskaram Canary Wharf Limited | Hospitality | 2026 |
| Namaskaram Canning Town Limited | Hospitality | 2026 |
| Namaskaram London Limited | Hospitality | 2019 |
| Namaskaram United Kingdom Limited | Hospitality | 2026 |
| Nanta Ltd | Other services | 2018 |
| NAQVI572 Ltd | Health & social care | 2024 |
| Nasco Search Limited | Administrative & support | 2016 |
| Nashdotbarbers Ltd | Other services | 2026 |
| Nateppy Ltd | Administrative & support | 2016 |
| Nationwide Business Ltd | Extraterritorial | 2024 |
| Nationwide Businesses Limited | Real estate | 1959 |
| Nature Environmental Limited | Professional & scientific | 2019 |
| Navaltech Engineering Ltd | Professional & scientific | 2024 |
| Navitrade Ltd | Wholesale & retail | 2023 |
| NCW Insight Limited | Professional & scientific | 2010 |
| Negussa Limited | Transport & logistics | 2017 |
| NEK Holdings Ltd | Real estate | 2026 |
| Nelike Capital Partners Ltd | Financial services | 2022 |
| Nephrite Consultancy Ltd | Information & communication | 2011 |
| Nestquest Reit Ltd | Hospitality | 2025 |
| NET Beauty Limited | Water & waste | 2026 |
| Nettles Investments Limited | Real estate | 2022 |
| Neugen Consulting Limited | Information & communication | 2024 |
| Neuroimaging SAS Ltd. | Health & social care | 2015 |
| Neurologic Limited | Construction | 1991 |
| Neutech Consulting Ltd | Professional & scientific | 2026 |
| New Pond International Limited | Real estate | 2016 |
| New Purley Food Center Ltd | Wholesale & retail | 2026 |
| New Unicorn Enterprise Ltd | Real estate | 2022 |
| Newtone Production Services Limited | Arts & recreation | 2025 |
| Next Chapter Housing Ltd | Health & social care | 2025 |
| Next Generation Boxing Academy Ltd | Arts & recreation | 2026 |
| Next Stepz Ltd | Real estate | 2019 |
| Nextfix Building & Heating Ltd | Construction | 2017 |
| Nexusconsultinglimited Ltd | Professional & scientific | 2025 |
| Nickd Ltd | Information & communication | 2022 |
| Nicleo Limited | Health & social care | 2019 |
| Niels Services Limited | Construction | 2025 |
| Nigel Thomas Financial Planning Limited | Financial services | 2014 |
| NIK Digital Ltd | Professional & scientific | 2020 |
| Nilavan Development Ltd | Real estate | 2025 |
| Nirmana Ltd | Professional & scientific | 2022 |
| Nirvana Limited | Real estate | 2015 |
| Nivesh Properties Limited | Real estate | 2019 |
| NJB Software Ltd | Information & communication | 2026 |
| NK Resoures Ltd | Administrative & support | 2017 |
| NKD Logistics Ltd | Transport & logistics | 2022 |
| NKR Associates Limited | Professional & scientific | 2007 |
| NMC Capital Holdings Limited | Financial services | 2026 |
| Nmpg Limited | Professional & scientific | 2025 |
| Nnhanced Derma Ltd | Other services | 2023 |
| NO.5 (Surrey) Limited | Hospitality | 2019 |
| Noble Capital Ltd | Hospitality | 2025 |
| Nora Mullally Limited | Professional & scientific | 2011 |
| Noso Fabrics Limited | Wholesale & retail | 2024 |
| Nostalgia Photography Ltd | Professional & scientific | 2025 |
| Nova Saloons Ltd | Real estate | 2026 |
| Novelty Investments Ltd | Administrative & support | 2016 |
| Novo Management Consulting Limited | Information & communication | 2017 |
| Novo Villas Ltd | Real estate | 2019 |
| Nramz Limited | Health & social care | 2008 |
| NSA Property Ltd | Real estate | 2015 |
| Numunday Limited | Construction | 2025 |
| NUR Management Limited | Real estate | 2013 |
| NXT GEN Boxing Academy Community Interest Company | Arts & recreation | 2024 |
| O C Obadare Limited | Health & social care | 2016 |
| O Farol Ltd | Hospitality | 2026 |
| Oakwood Heights Property Services Ltd | Real estate | 2019 |
| Oakwood Lodge Care Home Limited | Health & social care | 2016 |
| Oakwoods Management Limited | Households | 2025 |
| Oasis Healthcare Providers Ltd | Health & social care | 2020 |
| Obmd Limited | Education | 2015 |
| Obolus Services Limited | Wholesale & retail | 2014 |
| Obradovic Consulting Limited | Professional & scientific | 2022 |
| Obsidian Strategies Ltd | Real estate | 2025 |
| Occhio Medico Ltd | Health & social care | 2013 |
| Octal Limited | Information & communication | 2008 |