| MRB Transport Hampshire Ltd | Transport & logistics | 2002 |
| MRB Transport Holdings Ltd | Financial services | 2017 |
| Mrpk Commercial Ltd | Real estate | 2023 |
| MS Race Engineering Limited | Manufacturing | 2012 |
| MSQ Limited | Information & communication | 2026 |
| MTF Events Ltd | Hospitality | 2025 |
| MTN Projects Limited | Construction | 1978 |
| MTP Property Holdings Limited | Real estate | 2022 |
| Mudeford 1.0 Ltd | Real estate | 2020 |
| Mume Worldwide Ltd | Wholesale & retail | 2025 |
| Mumentum Consulting Ltd | Professional & scientific | 2024 |
| Muntjac Landscapes Ltd | Administrative & support | 2024 |
| Murray Technical Services Limited | Professional & scientific | 2013 |
| Mursell Limited | Financial services | 1993 |
| Musicplanetlive Limited | Administrative & support | 2017 |
| Musn'T Grumble Ltd | Information & communication | 2024 |
| Mutsuu Ltd | Health & social care | 2022 |
| My Debt Recovery Limited | Professional & scientific | 2022 |
| My Energy Claim Limited | Administrative & support | 2023 |
| My Little Explorers Ltd | Education | 2026 |
| My Local Surgery Ltd | Information & communication | 2024 |
| My-Logs Limited | Wholesale & retail | 2025 |
| Myriad Group Holdings Limited | Real estate | 2026 |
| N & C Lowe Limited | Professional & scientific | 2011 |
| N C 4 Romsey Limited | Households | 2023 |
| N&J Beauchamp Limited | Health & social care | 2020 |
| N.T. Building & Maintenance Limited | Construction | 2007 |
| Naeto Ltd | Information & communication | 2014 |
| Narain Estates Limited | Real estate | 2024 |
| Narwhals DEV Ltd | Information & communication | 2025 |
| Nathan Sessions Landscapes Ltd | Administrative & support | 2018 |
| Nationwide Paints Ltd | Wholesale & retail | 2025 |
| Natural Wisdom Organics Ltd | Manufacturing | 2012 |
| Naturzone Limited | Other services | 1999 |
| Navigatx Limited | Professional & scientific | 2022 |
| NBS4 Ltd | Extraterritorial | 2026 |
| NCS South Limited | Professional & scientific | 2019 |
| Neal Engineering Holdings Limited | Financial services | 2017 |
| Neat Sweeps Limited | Administrative & support | 2015 |
| Neeraj Ahuja Limited | Health & social care | 2022 |
| Neil Barnett Associates Limited | Administrative & support | 2012 |
| Neil Clarke Systems Engineering Limited | Other services | 2009 |
| Neilson Property Consultants Limited | Real estate | 2010 |
| Nella Pharmaceutical Products Limited | Professional & scientific | 1996 |
| NET Films Limited | Arts & recreation | 2016 |
| Neurostack AI Ltd | Information & communication | 2025 |
| New Build Carpentry Limited | Construction | 2018 |
| New Forest Building Services Ltd | Construction | 2021 |
| New Forest Business Consultants Ltd | Extraterritorial | 2019 |
| New Forest Folk Festival Limited | Arts & recreation | 2016 |
| New Forest Landscaping Services Limited | Administrative & support | 2013 |
| New Forest Stone Limited | Manufacturing | 2012 |
| New Forest Tea Company Ltd | Wholesale & retail | 2026 |
| New Forest Trust | Administrative & support | 2003 |
| New GEN Clothing Ltd | Wholesale & retail | 2026 |
| New Heritage Investments Ltd | Real estate | 2025 |
| New Leaf Environmental Ltd | Agriculture & fishing | 2019 |
| New Thread Ltd | Wholesale & retail | 2026 |
| Newbridge Plant Hire Limited | Administrative & support | 1991 |
| Newhouse Estates Limited | Professional & scientific | 2026 |
| Newlands Early Years Centre Limited | Education | 2021 |
| Newman Electrics Ltd | Construction | 2012 |
| Newmead Properties Limited | Construction | 2019 |
| Newton Lane Properties Limited | Real estate | 2025 |
| Newton Scott Commercial Property Agents Limited | Real estate | 2011 |
| Nexgen Carbon Zero Limited | Manufacturing | 2022 |
| Nexgen Heating Limited | Manufacturing | 2017 |
| Nichol Court Limited | Real estate | 2017 |
| Nichol Court Management Limited | Real estate | 2019 |
| Nicholas James Hospitality Ltd | Hospitality | 2024 |
| Nick Sharp Limited | Professional & scientific | 2025 |
| Nightingale (Nicholas) Limited | Construction | 2018 |
| Nightingale Distilleries Ltd | Wholesale & retail | 2021 |
| Nile Interiors Ltd | Manufacturing | 2017 |
| Nith Enterprises Limited | Wholesale & retail | 2021 |
| NITROGEN4U Limited | Administrative & support | 2025 |
| NIX Property Limited | Other services | 2012 |
| NK Sports Podiatry Limited | Health & social care | 2015 |
| NMH Medical Services LLP | | 2025 |
| NO 9 Performance Limited | Information & communication | 2019 |
| NO One Consultancy Limited | Professional & scientific | 2020 |
| Noble Roofing Services Limited | Construction | 2019 |
| North Stoneham Developments Limited | Real estate | 2011 |
| Northbrook Medical Limited | Health & social care | 2016 |
| Nova Foresta Fencing Limited | Administrative & support | 2023 |
| Nova Foresta Gate Installations Ltd | Administrative & support | 2024 |
| Novapure Naturals Ltd | Wholesale & retail | 2022 |
| NR (GB) Ltd | Hospitality | 2014 |
| NRJ Electrical Solutions Limited | Construction | 2017 |
| Ntpa Consultants Ltd | Professional & scientific | 2017 |
| NUE. Golf Ltd | Real estate | 2025 |
| Oak Cottage Management RTM Company Limited | Households | 2019 |
| Oaksway Anaesthetic Services Limited | Health & social care | 2019 |
| Oakwood Developments (Hampshire) Limited | Construction | 2021 |
| Oakwood Lodge Management Limited | Households | 2005 |
| Ocean Play Marine Limited | Manufacturing | 2022 |
| Ocean Snap Ltd | Wholesale & retail | 2025 |
| OCO Norway Limited | Financial services | 2008 |
| Odan Archives Ltd | Wholesale & retail | 2022 |
| Office Hub Hampshire Limited | Real estate | 2020 |