| Northern Counties Eventide Home Limited | Other services | 1986 |
| Northern Heights Scaffolding and Hire Ltd | Construction | 2026 |
| Northern Hostelries Ltd | Hospitality | 2018 |
| Northern Rise Transformation & Delivery Limited | Information & communication | 2026 |
| Northern Spa's Outlet Limited | Wholesale & retail | 2016 |
| Northmere Talent Ltd | Administrative & support | 2026 |
| Northwest One Travel Ltd | Extraterritorial | 2023 |
| Northwood (Southport & Ormskirk) Limited | Real estate | 2013 |
| Norwood Developments (Southport) Ltd | Construction | 2024 |
| Norwood Estates Management Ltd | Households | 2020 |
| Norwood Residential Lettings Ltd | Real estate | 2024 |
| Notion Psychological Services Limited | Health & social care | 2024 |
| Novalink Group Ltd | Transport & logistics | 2025 |
| Novaspec Consultancy Limited | Health & social care | 2024 |
| Novus Construction Management Ltd | Construction | 2014 |
| NOW Installations Ltd | Construction | 2018 |
| NP Flooring Ltd | Construction | 2015 |
| NPA Investments Ltd | Extraterritorial | 2013 |
| NPB88 Ltd | Arts & recreation | 2017 |
| NPF Developments Ltd | Real estate | 2023 |
| Npjt Accounting & Business Solutions Ltd | Professional & scientific | 2014 |
| Npjt Investments Limited | Professional & scientific | 2015 |
| NSL Care Limited | Health & social care | 2018 |
| NSS (Southport) Limited | Wholesale & retail | 2007 |
| NSS Medical Services Limited | Health & social care | 2021 |
| NT & G Services Limited | Professional & scientific | 2023 |
| NTC Hair Ltd | Other services | 2016 |
| Ntwaconsultancy Limited | Professional & scientific | 2026 |
| NU AGE Aesthetics Limited | Health & social care | 2015 |
| Nu-Way Food Program Ltd | Information & communication | 2025 |
| Nubiru Limited | Wholesale & retail | 2016 |
| Nugent Professional Services Ltd | Professional & scientific | 2014 |
| Nulook Decks Limited | Construction | 2021 |
| Number Nineteen Property Management Limited | Real estate | 2009 |
| Nunky Property Ltd | Real estate | 2024 |
| Nursery Gardens Birkdale Limited | Households | 2023 |
| Nutri Jenny Ltd | Health & social care | 2026 |
| Nutrition First Limited | Hospitality | 2018 |
| Nutrition JT Ltd | Manufacturing | 2020 |
| NW Access Maintenance Limited | Construction | 2014 |
| NW Cleaning Ltd | Administrative & support | 2020 |
| NW Garden Services Ltd | Administrative & support | 2020 |
| NW Heritage CIC | Professional & scientific | 2020 |
| NW Produce Ltd | Agriculture & fishing | 2025 |
| NW Sewing Company Ltd | Manufacturing | 2025 |
| NW Systems Ltd | Wholesale & retail | 2025 |
| Nwam Property Ltd | Real estate | 2025 |
| NWE UK (North West Exports) Ltd | Wholesale & retail | 2024 |
| NXT GEN Movil SL Ltd | Wholesale & retail | 2025 |
| NXT4 Pro Ltd | Wholesale & retail | 2025 |
| Ny-Lon Relocations Ltd | Hospitality | 2014 |
| O & M Construction Southport Ltd | Construction | 2017 |
| O J UK Solutions Limited | Information & communication | 2012 |
| O.S.S. Fofanas Healthcare Company Limited | Health & social care | 2019 |
| Oak Consulting Ltd | Education | 2013 |
| Oakbourne Care Ltd | Health & social care | 2026 |
| Oakfield Solutions Limited | Financial services | 2026 |
| Oakhurst (Southport) Limited | Construction | 1989 |
| Oaklands Enterprises Limited | Administrative & support | 2018 |
| Oakmere Grosvenor Limited | Financial services | 2025 |
| Oakwell Global Limited | Professional & scientific | 2023 |
| Oakwood House Apartments Management Limited | Households | 2013 |
| Oakworth Bank (Property) Limited | Households | 2003 |
| Oasis Land Development Limited | Other services | 2008 |
| Oasis Land Development Marketing Limited | Professional & scientific | 2025 |
| Oasis UK Food Groups Ltd | Manufacturing | 2024 |
| OAU Property Management Limited | Households | 2024 |
| Obscura Solutions Ltd | Administrative & support | 2025 |
| Obsidian Nutrition Ltd | Hospitality | 2017 |
| Occleshaw House Ltd | Construction | 2020 |
| Occupant Limited | Real estate | 2025 |
| Ocean Diagnostics Ltd | Wholesale & retail | 2026 |
| Ocean PPE Services Limited | Administrative & support | 2014 |
| Oceans Head Spa Ltd | Other services | 2025 |
| Oceanview Assets Ltd | Real estate | 2019 |
| Octane Marketing Limited | Professional & scientific | 2026 |
| Odour Control Solutions Limited | Manufacturing | 2013 |
| Odyssey Leisure Ltd | Wholesale & retail | 2026 |
| Odyssey Living Limited | Wholesale & retail | 2024 |
| Oecgassociates Ltd | Transport & logistics | 2025 |
| Oecgproperty Ltd | Households | 2025 |
| OFF the Rails, Redcar Ltd | Hospitality | 2022 |
| Offbeattreats Ltd | Hospitality | 2024 |
| Offerte DAL Web Ltd | Hospitality | 2017 |
| OFFICES4U Ltd | Real estate | 2019 |
| Official Studio a Ltd | Professional & scientific | 2026 |
| Ofriscate Limited | Wholesale & retail | 1977 |
| OH Beauty Churchtown Limited | Other services | 2019 |
| OJG Limited | Professional & scientific | 2015 |
| Olaf 2019 Ltd | Transport & logistics | 2019 |
| Olcote Property Limited | Real estate | 1999 |
| Old-School-Tools Ltd | Wholesale & retail | 2019 |
| Oldholly Developments Ltd | Real estate | 2001 |
| Olive Dental Group Limited | Health & social care | 2025 |
| Oliver & Oliver Limited | Professional & scientific | 2017 |
| Oliver & Thomas Ltd | Professional & scientific | 2024 |
| Oliver KAY Limited | Extraterritorial | 1996 |
| Olivia Annice Nails Ltd | Other services | 2023 |
| Olivia Martyn Limited | Professional & scientific | 2022 |
| Olivia Online Limited | Wholesale & retail | 2023 |