| Nash Property Solutions Ltd | Real estate | 2024 |
| Natem Properties Ltd | Real estate | 2023 |
| Nationwide Spray Foam Removal Ltd | Professional & scientific | 2025 |
| NB Thinks Limited | Professional & scientific | 2019 |
| NCB Avia Limited | Professional & scientific | 2019 |
| Nced Wargames Limited | Information & communication | 2025 |
| NCM Builders Ltd | Construction | 2025 |
| NDC Group Holdings Ltd | Financial services | 2024 |
| NDP Fencing Centre Limited | Wholesale & retail | 2017 |
| Nederland IP Ltd | Professional & scientific | 2010 |
| Neil Ayre Consulting Ltd | Professional & scientific | 2007 |
| Neil Goff Associates Ltd | Professional & scientific | 2026 |
| Neilmac. Pc.B Ltd. | Other services | 2002 |
| Neos Partners Ltd | Professional & scientific | 2024 |
| Neosdesign Ltd | Administrative & support | 2009 |
| Netivo Limited | Information & communication | 2022 |
| Nettoyage Lavie Ltd | Wholesale & retail | 2024 |
| Network Products Limited | Administrative & support | 2004 |
| Neutrik (UK) Limited | Wholesale & retail | 1992 |
| New Forest Clinics Limited | Health & social care | 2004 |
| New Minds Resourcing Ltd | Administrative & support | 2018 |
| New Technology Sales Ltd | Administrative & support | 2016 |
| Newberry Online Ltd | Wholesale & retail | 2012 |
| Nexovate Consulting Ltd | Professional & scientific | 2025 |
| Nexsite Ltd | Information & communication | 2024 |
| Nextdoor Odiham Limited | Hospitality | 2004 |
| Nextstep Web Ltd | Wholesale & retail | 2025 |
| Nexus Digital Consulting Ltd | Information & communication | 2022 |
| Nicety Studio Limited | Professional & scientific | 2023 |
| Nicholsons Lettings Limited | Extraterritorial | 2006 |
| Nicholsons Property Services Limited | Real estate | 2004 |
| Nimble Insight Limited | Information & communication | 2011 |
| NJB Architecture Ltd | Professional & scientific | 2020 |
| NL International Limited | Financial services | 2019 |
| NO.4 Aesthetics Ltd | Health & social care | 2019 |
| Noahs ARK Productions Limited | Administrative & support | 2014 |
| Noctis Hampshire Limited | Professional & scientific | 2024 |
| Non-Lethal Solutions Limited | Professional & scientific | 2012 |
| Nordic Bess Limited | Professional & scientific | 2023 |
| Norgrave Property Limited | Real estate | 2011 |
| North Drive Maintenance Limited | Administrative & support | 2016 |
| North Hampshire Services Ltd | Manufacturing | 2014 |
| North Star Financial Services Limited | Financial services | 2004 |
| Northcroft Court Residents Association Limited | Households | 1982 |
| Northern Chill Air Conditioning Ltd | Energy | 2025 |
| Northwick Croft Residents Association Limited | Households | 1997 |
| Norton Crane Limited | Professional & scientific | 2000 |
| Novaro Consulting Group Limited | Information & communication | 2020 |
| Novayou Ltd | Professional & scientific | 2022 |
| Novus Integration Limited | Professional & scientific | 2021 |
| NP Tree Management Ltd | Agriculture & fishing | 2011 |
| NS Innerskin Limited | Other services | 2025 |
| NU Battery Ltd | Wholesale & retail | 2022 |
| Number Solutions UK Limited | Administrative & support | 2005 |
| Nursery END (Eversley) Limited | Households | 2002 |
| O S C Residents Association (HW) Limited | Households | 1996 |
| O-Social Ltd | Professional & scientific | 2018 |
| O.A. Barraclough Limited | Construction | 1996 |
| Oak Broadcast Ltd | Information & communication | 2017 |
| Oak Grange Business Services Limited | Financial services | 2003 |
| Oakhelm Limited | Wholesale & retail | 1991 |
| Oakridge & Loxton Limited | Real estate | 2017 |
| Oakston Solutions Limited | Construction | 2018 |
| Oakstone House Property Services Ltd | Construction | 2026 |
| Oakwood Builders & Developments Limited | Construction | 2014 |
| Oakwood Homes Hampshire Limited | Construction | 2024 |
| Oast House Residents Association Limited | Households | 1998 |
| Oatesco Ltd | Other services | 2025 |
| OBE1 Consulting Limited | Real estate | 2019 |
| OBL Group Limited | Manufacturing | 2017 |
| Observe Ltd | Health & social care | 2023 |
| Octave Group Limited | Wholesale & retail | 2026 |
| Oculo Ltd | Information & communication | 2002 |
| ODI Green Limited | Hospitality | 2026 |
| Odiham & Villages Ltd | Construction | 2017 |
| Odiham Community Interest Company | Hospitality | 2022 |
| Odiham Contractors Ltd | Construction | 2025 |
| Odiham Cottage Hospital Combined Trusts (Incorporating the League of Friends of OCH) Limited | Health & social care | 1998 |
| Odiham Cottage Hospital Shops Limited | Wholesale & retail | 2014 |
| Odiham Hardware Limited | Wholesale & retail | 2004 |
| Odiham Investments Limited | Financial services | 2026 |
| Odiham Joinery Limited | Manufacturing | 2018 |
| Odiham Tennis Club Limited | Arts & recreation | 2019 |
| OH Skin Medical Asethetics Limited | Other services | 2021 |
| Ohana Skin Limited | Wholesale & retail | 2023 |
| OHW Limited | Construction | 2001 |
| Ojas Software Consultancy Services Limited | Construction | 2015 |
| Okerage Ltd | Construction | 2022 |
| ON Q Communications Limited | Information & communication | 2011 |
| Onder Forklift Ltd | Manufacturing | 2020 |
| One Blue Sphere Ltd | Information & communication | 2011 |
| One Engine Limited | Information & communication | 2020 |
| One One Three Management Limited | Extraterritorial | 2015 |
| One Stop Accounting Limited | Professional & scientific | 1994 |
| One Stop Accounting UK Ltd | Professional & scientific | 2002 |
| Open Applications Ltd | Information & communication | 2021 |
| Opencloudbss Limited | Information & communication | 2017 |
| Optimum Conversions Limited | Real estate | 2016 |
| Optimus School of Motoring Limited | Education | 2009 |
| Orange Cat Solutions Ltd | Information & communication | 2019 |