| Mproperties Limited | Real estate | 2018 |
| MPZ Executive Partners Ltd | Professional & scientific | 2026 |
| MR B Creative Ltd | Professional & scientific | 2017 |
| MR Charger Maintenance Services Limited | Construction | 2021 |
| MR EV Charger Ltd | Construction | 2020 |
| MR Turtle Ltd | Hospitality | 2021 |
| MT Graphic Design Limited | Wholesale & retail | 2020 |
| Mugshot Monday Ltd | Wholesale & retail | 2021 |
| Mumford Plumbing Ltd | Construction | 2022 |
| Muse Maker Developments Limited | Real estate | 2025 |
| Mushu Properties Limited | Real estate | 2024 |
| Music Education Services Ltd | Education | 2022 |
| Must Global Ltd | Wholesale & retail | 2018 |
| MV Property Services Ltd | Real estate | 2019 |
| MVD Heating and Plumbing Ltd | Construction | 2014 |
| MW Project Management Limited | Construction | 2023 |
| Mybigoneiro Limited | Wholesale & retail | 2023 |
| Myra Staffing Solutions Ltd | Administrative & support | 2024 |
| MZL FX Ltd | Wholesale & retail | 2022 |
| N J Toms Consultants Limited | Information & communication | 2020 |
| N&K Management Limited | Professional & scientific | 2019 |
| Nagy Solutions Ltd | Information & communication | 2017 |
| Nails Masters Trading AS UK Nails Ltd | Other services | 2017 |
| Nakai Ventures Ltd | Information & communication | 2025 |
| Nala the Needy Rottie Ltd | Arts & recreation | 2022 |
| Natal Holdings Limited | Financial services | 2023 |
| Natural Healthy Centre Limited | Health & social care | 2011 |
| Naturalife Limited | Wholesale & retail | 1989 |
| Naufel Ltd | Transport & logistics | 2022 |
| NBM Ltd | Construction | 2023 |
| NCK Consulting Limited | Information & communication | 2016 |
| Ncrw Consultancy Ltd | Administrative & support | 2024 |
| NDC Services Limited | Transport & logistics | 2007 |
| Nedu T/A Tops Pizza Ltd | Hospitality | 2025 |
| Neecaz Ltd | Financial services | 2024 |
| Need an Electrician Ltd | Construction | 2023 |
| Neil Hawkes Ltd | Arts & recreation | 2020 |
| Nekimaya Properties Ltd | Real estate | 2024 |
| Neldintay Racing Limited | Arts & recreation | 2024 |
| Neomarketplace Ltd | Wholesale & retail | 2021 |
| Nessy Nails Ltd | Other services | 2026 |
| Network Talent Commercial Limited | Administrative & support | 2025 |
| Network Talent Technology Ltd | Administrative & support | 2025 |
| New Basilo Pizza Limited | Hospitality | 2020 |
| Newglass Ashford Limited | Construction | 2023 |
| Newglass Limited | Construction | 2004 |
| Newquay Beach Holiday Homes Ltd | Real estate | 2021 |
| Newton LEX Limited | Professional & scientific | 2006 |
| Nexgen Technology Services Ltd | Information & communication | 2024 |
| Nexis Ventures Ltd | Real estate | 2024 |
| Nexus Corporate Solution PVT Limited | Information & communication | 2023 |
| Niche Contracts Limited | Professional & scientific | 2015 |
| Nichols Marcy Dawson LLP | | 2018 |
| Nick & Belle Company Ltd | Manufacturing | 2022 |
| Nicocha Ltd | Administrative & support | 2017 |
| Nicola Humphreys Ltd | Professional & scientific | 2019 |
| Nisou Limited | Hospitality | 2024 |
| NJ Eyecare Ltd | Financial services | 2025 |
| Njord Consultancy Ltd | Information & communication | 2025 |
| NK Carpentry Ltd | Manufacturing | 2023 |
| NNL Ltd | Health & social care | 2025 |
| Noah Abey Ltd | Wholesale & retail | 2026 |
| Northcell Services Ltd | Real estate | 2015 |
| Nova Builds Group Ltd | Professional & scientific | 2025 |
| Nova Change Consulting Ltd | Professional & scientific | 2025 |
| Nova Global Foods Ltd | Hospitality | 2026 |
| Novy Build Limited | Construction | 2016 |
| NOW Active Ltd | Information & communication | 2024 |
| NP Investment Properties Ltd | Real estate | 2025 |
| Np-Pharma Ltd | Professional & scientific | 2024 |
| Npbg Limited | Information & communication | 2010 |
| NPH Maintenance Ltd | Construction | 2021 |
| NS Endeavours Ltd | Information & communication | 2024 |
| Ntth Consulting Limited | Professional & scientific | 2020 |
| Nulifit Limited | Arts & recreation | 2016 |
| Numi Hamodh Ltd | Hospitality | 2025 |
| Nutrikane (UK) Ltd | Wholesale & retail | 2023 |
| Nvdn Consulting Limited | Information & communication | 2017 |
| Nxis.Io Limited | Information & communication | 2017 |
| NY Design . Ltd | Professional & scientific | 2012 |
| Nyshi Ltd | Information & communication | 2026 |
| O & O Holdings Limited | Professional & scientific | 2017 |
| O W G Management Ltd | Administrative & support | 1985 |
| Oak & ASH Investments Ltd | Professional & scientific | 2006 |
| Oak Lodge Close (Hersham) Limited | Households | 2000 |
| Oakleaf Capital Ltd | Other services | 2023 |
| OBI Realty Group Ltd | Administrative & support | 2024 |
| Octiva Ltd | Information & communication | 2017 |
| Octopus Security Limited | Information & communication | 2025 |
| Office Relocation Services Ltd | Transport & logistics | 2019 |
| Ogled Limited | Wholesale & retail | 2012 |
| Oldsel Financial Ltd | Financial services | 2009 |
| Oliver Consulting Ltd | Professional & scientific | 2026 |
| Ollies Homes CIC | Real estate | 2023 |
| Olly Starkey Ltd | Information & communication | 2018 |
| Olnesta Ltd | Information & communication | 2026 |
| Omni Academy of Beauty Limited | Education | 2008 |
| Omraj Childcare Ltd | Health & social care | 2019 |
| ON the Ball Events Ltd | Administrative & support | 2024 |
| ON Top Solutions Limited | Administrative & support | 2024 |