| Nova Insight Online Ltd | Other services | 2021 |
| Nova Nutrition Ltd | Health & social care | 2018 |
| Nova Opulentia Ltd | Wholesale & retail | 2025 |
| Nova Story Events Ltd | Administrative & support | 2024 |
| NOVA4MOTION Ltd | Education | 2026 |
| Novabud Limited | Manufacturing | 2024 |
| Novabuild Property Ltd | Construction | 2026 |
| Novacolab Limited | Wholesale & retail | 2026 |
| Novara Lounge Ltd | Other services | 2025 |
| Novem Holdings Ltd | Health & social care | 2018 |
| Noventrix Global Ltd | Information & communication | 2026 |
| Novo Delis (Southampton) Limited | Hospitality | 2019 |
| Novopro Facilities Management Ltd | Construction | 2026 |
| Novopro Services (South) Ltd | Construction | 2023 |
| Novopro Services Ltd | Construction | 2026 |
| NOW Drainage & Plumbing Services Ltd | Water & waste | 2024 |
| Nowpod Property Limited | Real estate | 2017 |
| NP Lounge Ltd | Hospitality | 2024 |
| NPS Contracts Limited | Construction | 2017 |
| NPX Global Ltd | Information & communication | 2025 |
| NR Performance Coaching Ltd | Education | 2025 |
| NRG Operations Ltd | Real estate | 2017 |
| NRG Power Systems Limited | Wholesale & retail | 2003 |
| Nrunaina Limited | Real estate | 2020 |
| NSL Developments Ltd | Real estate | 2019 |
| NSL Homes Limited | Real estate | 2019 |
| NSN Travel Limited | Professional & scientific | 2019 |
| NSP Electrical Limited | Construction | 2023 |
| NSP Services Limited | Real estate | 2023 |
| NSZ Management Limited | Real estate | 2016 |
| NT Distributions Limited | Transport & logistics | 2018 |
| NT Global Ltd | Extraterritorial | 2026 |
| NT Plumbing & Electrical Ltd | Construction | 2026 |
| NTM Future Holdings Ltd | Real estate | 2026 |
| NTS UK Global Engineering Services Ltd | Professional & scientific | 2018 |
| Nuage Agency Limited | Professional & scientific | 2014 |
| Nuba Technologies Ltd | Information & communication | 2025 |
| Nude Global Limited | Manufacturing | 2018 |
| Nudecnc Ltd | Other services | 2017 |
| Nudnut Services Limited | Professional & scientific | 2013 |
| Nullware Digital Ltd | Information & communication | 2025 |
| Number Seven Service Design Ltd | Information & communication | 2017 |
| Numerint Limited | Information & communication | 2022 |
| Nunicornucopia Limited | Real estate | 2023 |
| Nuotro Limited | Wholesale & retail | 2025 |
| Nupeak Roofing Limited | Construction | 2025 |
| Nurse Aesthetics and Skincare Bournemouth Ltd | Health & social care | 2025 |
| Nurse Cosmetics Ltd | Health & social care | 2016 |
| Nursery Food by Alex Limited | Hospitality | 2014 |
| Nursery Road RTM Company Limited | Households | 2010 |
| Nurtured Shift Studio Ltd | Education | 2026 |
| Nurtured Tech Ltd. | Professional & scientific | 2018 |
| Nurturing Birth Limited | Education | 2005 |
| Nutratouch Ltd | Wholesale & retail | 2024 |
| Nutrisfa Food Ltd | Manufacturing | 2024 |
| Nuttall Painters Limited | Construction | 2018 |
| Nutz Crazy Ltd | Wholesale & retail | 2020 |
| Nuudle Bar Holdings Limited | Wholesale & retail | 2019 |
| Nuvore Kreation Ltd | Manufacturing | 2025 |
| Nuvu Training Limited | Professional & scientific | 2014 |
| NWM Commercial Ltd | Administrative & support | 2016 |
| NWM Contracting (Ireland) Limited | Administrative & support | 2024 |
| NWM Contracting Ltd | Administrative & support | 2016 |
| NWM Solutions Ltd | Administrative & support | 2007 |
| Nyanga Sculptural Art Limited | Arts & recreation | 2022 |
| Nylo Projects Limited | Construction | 2025 |
| NZR Food Ltd | Wholesale & retail | 2023 |
| O & J Limited | Professional & scientific | 2013 |
| O a Thomas & Co. Consulting Limited | Professional & scientific | 2022 |
| O G Invest Limited | Manufacturing | 2015 |
| O G Manufacturing Limited | Manufacturing | 2015 |
| O&M Strategic Consultancy Ltd | Transport & logistics | 2022 |
| O'Connell Health Limited | Health & social care | 2018 |
| O'Neil Digging Services Ltd. | Other services | 2012 |
| O.B.E. 2 Limited | Wholesale & retail | 2005 |
| O:Pen Electrical Ltd | Construction | 2024 |
| Oak Accounting Ltd | Professional & scientific | 2011 |
| Oak Gardens (Wallisdown) Management Ltd | Households | 2008 |
| Oak-Lee Homes Ltd | Real estate | 2019 |
| Oakbridge Commercial Cleaning Ltd | Administrative & support | 2022 |
| Oakes Group Ltd | Professional & scientific | 2024 |
| Oakford Fine Carpentry Ltd | Construction | 2016 |
| Oakguys Limited | Manufacturing | 2022 |
| Oakham Grange (Block a) Limited | Households | 2008 |
| Oakham Grange (Block B) Limited | Households | 2008 |
| Oakleigh Flats Management Company Limited | Households | 1968 |
| Oakley Bell Limited | Construction | 2022 |
| Oakley CAD Services Limited | Professional & scientific | 2004 |
| Oakmeadian Risk Management Ltd | Administrative & support | 2011 |
| Oakshade Developments (Carter's) Ltd | Construction | 2022 |
| Oakshade Developments Limited | Financial services | 2018 |
| Oakvien Ltd | Other services | 2025 |
| Oakwood House Management Limited | Households | 1987 |
| Oasis FUN Ltd | Arts & recreation | 2022 |
| Oasis Healthcare Solutions Ltd | Health & social care | 2014 |
| Oasis Water Energy Group Limited | Professional & scientific | 2015 |
| Oban Consultants Ltd | Professional & scientific | 2019 |
| Obasan Services Limited | Administrative & support | 2017 |
| Obayi Limited | Health & social care | 2024 |
| Obelisk Corporate Services Ltd | Professional & scientific | 2023 |