| Msdl Homes Ltd | Construction | 2025 |
| MSJ ( South Coast ) Limited | Administrative & support | 2022 |
| Muchgide Ltd | Health & social care | 2015 |
| Mullings Limited | Construction | 2025 |
| Murros-Pearce Limited | Health & social care | 2017 |
| Musaso Limited | Health & social care | 2025 |
| Musical Associates (UK) Limited | Arts & recreation | 1998 |
| MV Classics Limited | Wholesale & retail | 2006 |
| MVA Technologies Ltd | Transport & logistics | 2025 |
| MVP Properties Ltd | Real estate | 2019 |
| MW Tasty Gosport Limited | Hospitality | 2016 |
| My Lamp Limited | Wholesale & retail | 2024 |
| Mysitevisitors Ltd | Information & communication | 2019 |
| Mystic Earth Limited | Wholesale & retail | 2016 |
| N & P Properties (South Coast) Limited | Real estate | 2019 |
| N.A Group (Hampshire) Ltd | Professional & scientific | 2026 |
| Nallow Properties Ltd | Real estate | 2023 |
| Nannas Nest Limited | Health & social care | 2025 |
| Nathan Bates Building Services Limited | Construction | 2016 |
| Nathan Trevor Lazenbury Limited | Real estate | 2019 |
| Natural Beauty Clinic Ltd | Other services | 2023 |
| Nauti Engines Ltd | Manufacturing | 2025 |
| Nayem Brothers Ltd | Hospitality | 2026 |
| NBA Building Solutions Limited | Construction | 2025 |
| Neama International Trading Ltd | Wholesale & retail | 2023 |
| Neatfix Fencing Ltd | Construction | 2014 |
| Nelek Limited | Hospitality | 2021 |
| Neon Numbers Software Limited | Information & communication | 2015 |
| Neoswim Ltd | Education | 2022 |
| Nerak Properties Ltd | Real estate | 2005 |
| Nergize Limited | Extraterritorial | 2021 |
| Neriston Ltd | Wholesale & retail | 2025 |
| Nesbitt Clegg Limited | Professional & scientific | 2017 |
| Nest & Anchor Events Limited | Professional & scientific | 2022 |
| Netherton Road Limited | Real estate | 2018 |
| Network Glazing Limited | Construction | 2019 |
| New Flight Ltd | Manufacturing | 2023 |
| New Forest Investments Limited | Manufacturing | 2019 |
| New Safety Training Ltd | Professional & scientific | 2016 |
| Newdrives Limited | Extraterritorial | 2002 |
| Newtown Property Investments Ltd | Real estate | 2019 |
| Nextech Consultancy Ltd | Information & communication | 2025 |
| Nexus Evaluation Ltd | Professional & scientific | 2021 |
| Nguemma Limited | Health & social care | 2015 |
| Ngummy's Culinary Services Ltd | Hospitality | 2024 |
| Nikki Henderson Sailing Ltd | Education | 2023 |
| Ninos Cafes Ltd | Hospitality | 2026 |
| Niso Holdings Limited | Real estate | 2024 |
| Nivex Ltd | Manufacturing | 2022 |
| Niyaz Brothers Limited | Hospitality | 2018 |
| NJS Engineering Limited | Manufacturing | 2002 |
| NJS Pest Control Ltd | Administrative & support | 2024 |
| NMC Dental Ltd | Health & social care | 2012 |
| Nocanos Enterprise Limited | Transport & logistics | 2024 |
| Noon Jewellery Ltd | Wholesale & retail | 2021 |
| Noran Fire Services Ltd | Public administration | 2024 |
| Nordis & Co UK Ltd | Wholesale & retail | 2025 |
| Norjon Precision Engineering Limited | Manufacturing | 2025 |
| North Actionsports Group Limited | Professional & scientific | 2018 |
| North Sails Limited | Manufacturing | 2005 |
| Northcott House Limited | Health & social care | 2012 |
| NOT Open ALL Hours Limited | Extraterritorial | 2020 |
| Novastar Developments Limited | Construction | 2017 |
| Novastar Management Limited | Real estate | 2017 |
| Novo Alarm Systems Ltd | Administrative & support | 2025 |
| Novo Recruit Ltd | Administrative & support | 2024 |
| NPH Investors Limited | Real estate | 2019 |
| NS Stan Limited | Health & social care | 2022 |
| NSC Pro Consultancy Ltd | Professional & scientific | 2025 |
| NTG Europe (UK) Limited | Professional & scientific | 2014 |
| NTL Enterprises Limited | Wholesale & retail | 2012 |
| Nwsd Properties Ltd | Real estate | 2013 |
| Nyasabnb Ltd | Administrative & support | 2026 |
| OAB Entertainment Limited | Information & communication | 2024 |
| Oakbridge Consultancy Ltd | Professional & scientific | 2023 |
| Oakhouse Foods (Stubbington) Ltd | Wholesale & retail | 2003 |
| Oaklands Fitness Limited | Arts & recreation | 2026 |
| Oaktree Family Group Ltd | Education | 2004 |
| Oarsome Chance | Education | 2015 |
| Oasis Bathroom Solutions Ltd | Construction | 2024 |
| Ocean Fish FC Ltd | Hospitality | 2024 |
| Ocean Marine Electronics Ltd | Manufacturing | 2013 |
| OCL Project Services Ltd | Construction | 2025 |
| Octavius Industries Limited | Professional & scientific | 2018 |
| Ogie & Family Ltd | Health & social care | 2023 |
| OJ Cleaning Ltd | Administrative & support | 2026 |
| Okoe Limited | Real estate | 2020 |
| Oladayo Jeje Ltd | Health & social care | 2020 |
| Oldrose Estates Ltd | Real estate | 2003 |
| Oliver Heer Ocean Racing Ltd | Professional & scientific | 2025 |
| OMA Marinie's Limited | Manufacturing | 2015 |
| Omniflux Meter Company Ltd. | Professional & scientific | 2004 |
| ON Site Service Ltd | Construction | 2013 |
| ON the Solent Bakery Ltd | Manufacturing | 2023 |
| On-Cue Communications Limited | Information & communication | 2011 |
| One Box of Fudge Limited | Wholesale & retail | 2026 |
| One for Sorrow Ltd | Wholesale & retail | 2019 |
| One Network Logistics Ltd | Transport & logistics | 2025 |
| Oneeddy Ltd | Information & communication | 2025 |
| Onlow Ltd | Administrative & support | 2010 |