| NK Euroways Ltd | Transport & logistics | 2019 |
| NK Management (Chatham) Limited | Real estate | 2011 |
| NMC Accountants Ltd | Professional & scientific | 2014 |
| NMC Estimating Ltd | Professional & scientific | 2026 |
| NMC Retail Ltd | Wholesale & retail | 2022 |
| NMC Tax Advisors Ltd | Professional & scientific | 2020 |
| NNK Property Ltd | Real estate | 2012 |
| NO Stress Limited | Information & communication | 2020 |
| NO.64 Coffee & Brunch Ltd | Hospitality | 2020 |
| NO.8 Luxury Stays Ltd | Financial services | 2025 |
| Noble Clothiers Limited | Other services | 2008 |
| Noble One Accountants Limited | Professional & scientific | 2021 |
| Noble One Art Limited | Real estate | 2025 |
| Noble One Capital Group Ltd | Financial services | 2023 |
| Noble One Consulting Limited | Administrative & support | 2024 |
| Noble One Investments Limited | Real estate | 2021 |
| Nobleserve Properties Ltd | Real estate | 2020 |
| Nobleserve UK Limited | Administrative & support | 2017 |
| Nolly Home Ltd | Wholesale & retail | 2025 |
| Non-Toxic Living Co. Ltd | Wholesale & retail | 2025 |
| Nonnigates Limited | Professional & scientific | 2013 |
| Nonyido Ltd | Professional & scientific | 2017 |
| Nordic Entertainment Ltd | Other services | 2007 |
| Nordic Property Partner Solution Ltd | Real estate | 2018 |
| Norion Foods Ltd | Hospitality | 2026 |
| Norion Luxury Ltd | Wholesale & retail | 2023 |
| Norman Road Developments Ltd | Real estate | 2019 |
| Normso Estate Ltd | Real estate | 2024 |
| Norse Health and Safety Group Ltd | Public administration | 2022 |
| North Electrical Services Ltd | Construction | 2017 |
| North Kent Joinery Limited | Manufacturing | 1982 |
| North Kent Property Management Ltd | Households | 2023 |
| North Property Solutions Ltd | Construction | 2015 |
| North Road Holdings Ltd | Real estate | 2020 |
| North Star Residential/Commercial Cleaning Services Ltd | Administrative & support | 2008 |
| Northern Four Limited | Real estate | 2025 |
| Northfield Services Ltd | Construction | 2026 |
| Northstar Nexus Ltd | Professional & scientific | 2025 |
| Northstarsolutionz Ltd | Information & communication | 2026 |
| Northumberland Mews (Margate) Management Company Limited | Households | 2020 |
| Norzac Limited | Administrative & support | 2021 |
| NOT Just a Destination Travel Ltd | Administrative & support | 2025 |
| Nouveaux Ltd | Information & communication | 2019 |
| Novadrops Ltd | Wholesale & retail | 2025 |
| Novatec Engineering Limited | Manufacturing | 2013 |
| Novel Line Limited | Wholesale & retail | 2025 |
| Novoberry Solutions Ltd | Wholesale & retail | 2025 |
| NPD Orthotics Limited | Health & social care | 2009 |
| NPL Technical Ltd | Manufacturing | 2014 |
| NPS Investment Holdings Ltd | Financial services | 2021 |
| Npsk Holdings Ltd | Real estate | 2017 |
| NRD Property Limited | Construction | 2018 |
| NRG Property Management Limited | Real estate | 2016 |
| NRH 1 Ltd | Construction | 2022 |
| NRS Northern Limited | Wholesale & retail | 2017 |
| NRS Projects Limited | Real estate | 2019 |
| Nsai Limited | Wholesale & retail | 2019 |
| Nsnow Construct Ltd Ltd | Construction | 2025 |
| Nstall Network UK Ltd | Construction | 2022 |
| NTV Holding Limited | Financial services | 2026 |
| Nu-Del Ltd | Wholesale & retail | 2021 |
| Numuun NRG Ltd. | Wholesale & retail | 2021 |
| Nuqlea Limited | Financial services | 2021 |
| Nurture 4 Life Limited | Manufacturing | 2015 |
| Nurture Space Childcare Limited | Hospitality | 2026 |
| Nurturepoint Services Ltd | Health & social care | 2026 |
| Nuwill Limited | Professional & scientific | 2020 |
| Nuzzyysam Limited | Administrative & support | 2018 |
| NV Sedations Limited | Health & social care | 2020 |
| Nwanne & Associates Ltd | Health & social care | 2019 |
| Nyschey Ltd | Information & communication | 2022 |
| O Louis-Jean Limited | Health & social care | 2014 |
| O'Neill Surgery Limited | Health & social care | 2018 |
| O.J. Co-Operation Limited | Professional & scientific | 2023 |
| OA Rental Properties Ltd | Real estate | 2025 |
| OAD Consults Limited | Administrative & support | 2019 |
| Oakdean Construction Limited | Real estate | 2015 |
| Oakes Insulation Services Limited | Construction | 2018 |
| Oakes Power Services Limited | Manufacturing | 2015 |
| Oakes Properties Limited | Real estate | 1987 |
| Oakes Property Ltd | Real estate | 2024 |
| Oakfield South East Limited | Construction | 2025 |
| Oakley Roofing & Building Ltd | Construction | 2019 |
| Oaks Carpentry & Construction Limited | Manufacturing | 2024 |
| Oakshade Properties Limited | Real estate | 2010 |
| Oaktree Electrical Limited | Construction | 1996 |
| Oaktree Group Services Limited | Administrative & support | 2008 |
| Oaktree Power Group Limited | Financial services | 2023 |
| Oaktrees BG Limited | Administrative & support | 2024 |
| OAL Solutions Ltd | Professional & scientific | 2022 |
| Oami Ltd | Real estate | 2023 |
| OAO Medical Ltd | Health & social care | 2024 |
| Oasim Ltd | Health & social care | 2015 |
| Oastview Electrical Limited | Construction | 2020 |
| OBD Property Group Ltd | Real estate | 2026 |
| OBD2AI Ltd | Information & communication | 2025 |
| Obervia Ltd | Wholesale & retail | 2025 |
| Obsidian Software Services Limited | Information & communication | 2021 |
| Ocean Breaks Ltd | Real estate | 2026 |
| Ocean Cleaning London Ltd | Administrative & support | 2013 |