| Newlands Property Solutions Limited | Real estate | 2024 |
| Newlook Barber Lichfield Ltd | Other services | 2024 |
| Newman Catering Ltd | Hospitality | 2024 |
| Newmans Limited | Professional & scientific | 1987 |
| Newpool Construction Limited | Construction | 1973 |
| Newport 9 Consulting Ltd | Professional & scientific | 2024 |
| Newticket Limited | Professional & scientific | 1998 |
| Next Destination Consulting Limited | Administrative & support | 2013 |
| Next Level Investors Ltd | Real estate | 2021 |
| Next Steps Aftercare Limited | Health & social care | 2007 |
| Nextstone Capital UK Limited | Financial services | 2023 |
| Nexus Holding Corporation Ltd | Financial services | 2024 |
| NG Alexander Ltd | Administrative & support | 2021 |
| Nial Boylan Limited | Professional & scientific | 2012 |
| Nice Leisure Holdings Limited | Professional & scientific | 2011 |
| Nice Leisure Limited | Real estate | 2005 |
| Nicholls FD Properties Limited | Households | 2017 |
| Nicisent Ltd | Health & social care | 2020 |
| Nick Martin Services Limited | Transport & logistics | 2018 |
| Nick Rafferty Ltd | Financial services | 2014 |
| Nifty Media by Nick Mobley Ltd | Information & communication | 2023 |
| Nimble Numbers Limited | Professional & scientific | 2021 |
| Nine Sixty SIX Limited | Health & social care | 2023 |
| Ninetyfold Slang Field Ltd | Mining & quarrying | 2015 |
| Nippi Cars Limited | Administrative & support | 2002 |
| Nippi Vehicles Limited | Manufacturing | 1997 |
| Nippon Distribution Limited | Manufacturing | 1989 |
| Nippon E-Bikes Limited | Wholesale & retail | 2022 |
| NJM Property Renovations Ltd | Construction | 2024 |
| NKB Property Solutions Ltd | Real estate | 2021 |
| NKF Group Limited | Professional & scientific | 2017 |
| NKG Composite Limited | Construction | 2019 |
| NKG Group Limited | Financial services | 2019 |
| NMA Automotive Car Sales Ltd | Wholesale & retail | 2021 |
| Noddy Park Properties Ltd | Real estate | 2025 |
| Nomad Waffles Ltd | Hospitality | 2018 |
| Non-Physical Ltd | Other services | 2025 |
| Nonky Limited | Hospitality | 2023 |
| Norgren Limited | Wholesale & retail | 1956 |
| Normans Bookkeeping & Payroll Limited | Professional & scientific | 2015 |
| Normans Holdings Ltd | Financial services | 2025 |
| Normans Troncmaster Services Ltd | Administrative & support | 2021 |
| North Channel Advisory Limited | Other services | 2001 |
| North Channel Invest Limited | Other services | 2013 |
| Northbourne Investments Limited | Real estate | 2005 |
| Northern Graders Ltd | Arts & recreation | 2025 |
| Northern Monkey Wood Works Limited | Administrative & support | 2019 |
| Norton Aquaculture Limited | Agriculture & fishing | 2016 |
| Norton Fishery Management Limited | Agriculture & fishing | 2016 |
| NOT Big - BUT Clever Limited | Extraterritorial | 2015 |
| NOT Just Travel With AMI Ltd | Administrative & support | 2024 |
| Novametal Wire UK Limited | Wholesale & retail | 2018 |
| Novavet Services Limited | Professional & scientific | 2025 |
| Nowka 71 Limited | Hospitality | 2020 |
| NP Jenkinson Ltd | Manufacturing | 2021 |
| NPX Wholesale Limited | Wholesale & retail | 2022 |
| NRG Assessments Ltd | Administrative & support | 2015 |
| Nstruct Corporate Training Limited | Administrative & support | 2015 |
| NTG Ebrex UK Ltd | Transport & logistics | 2006 |
| NTG Road UK Limited | Transport & logistics | 2016 |
| NTN Bearings (UK) Limited | Wholesale & retail | 1964 |
| NTS Construction Limited | Construction | 2017 |
| Numan Park Ltd | Hospitality | 2025 |
| Numero UNO (UK) Ltd | Manufacturing | 2009 |
| Nursery END Limited | Wholesale & retail | 2024 |
| Nurture Community CIC | Administrative & support | 2019 |
| Nutrition UP Ltd | Wholesale & retail | 2025 |
| Nuwine Limited | Wholesale & retail | 2023 |
| NW Event Solutions Ltd | Administrative & support | 2024 |
| NW Intelisol Limited | Manufacturing | 2016 |
| Nybc Ltd | Construction | 2026 |
| Nykku Air Conditioning Limited | Construction | 2021 |
| O'Boyle Brothers Plant Hire Limited | Administrative & support | 2011 |
| O'Sullivan & SON Ltd | Professional & scientific | 1999 |
| Oak & IVY Homes Limited | Real estate | 2020 |
| Oak Residential Management Company Ltd | Real estate | 2015 |
| Oak Tree Trust | Health & social care | 1993 |
| Oakham Business Services Limited | Professional & scientific | 2017 |
| Oakhurst Interiors & Fittings Limited | Wholesale & retail | 2019 |
| Oakley Consultancy Services Limited | Financial services | 2017 |
| Oakshower Services Limited | Wholesale & retail | 1987 |
| Oakwood Home & Developments Limited | Construction | 2024 |
| OAS Freehold Limited | Construction | 2020 |
| OAS Freehold Title Limited | Real estate | 2024 |
| OAS Park 2024 Limited | Real estate | 2024 |
| Oasl 10 Limited | Real estate | 2023 |
| Oblivion Limited | Health & social care | 2025 |
| OBP Holdings Limited | Financial services | 2022 |
| Obsession Salon & Spas Limited | Other services | 2002 |
| Occumed Ltd | Health & social care | 2023 |
| OCH Blockley Management Company Limited | Households | 2018 |
| Octagon Medical & Security Solutions Ltd | Administrative & support | 2018 |
| Octopox Ltd | Arts & recreation | 2024 |
| Octopus Podiatry Ltd | Health & social care | 2024 |
| ODC Services Ltd | Real estate | 2018 |
| Ogden Media Group Ltd | Professional & scientific | 2022 |
| OGM Trade Ltd | Wholesale & retail | 2023 |
| Ohsl Ltd | Real estate | 2020 |
| Oikos Rentals Limited | Real estate | 2025 |
| Old Art School Management Ltd | Real estate | 2019 |