| Medway Homes (Southern) Ltd | Construction | 2025 |
| Medway Homes Ltd | Construction | 2025 |
| Meliora Accounting Solutions Limited | Professional & scientific | 2012 |
| Memorial ARM Bands Limited | Wholesale & retail | 2016 |
| Mengeham Rythe Sailing Club Limited | Arts & recreation | 2024 |
| Mercer South Ltd | Construction | 2025 |
| Mercer Southern Ltd | Construction | 2026 |
| Merton House Limited | Households | 1982 |
| Metis Hangars Ltd | Manufacturing | 2017 |
| Michael J. Camp Limited | Extraterritorial | 1934 |
| Mick's Fishing Tackle Ltd | Wholesale & retail | 2018 |
| Midhurst Taverns Limited | Hospitality | 2017 |
| Millers of Hayling Limited | Real estate | 2002 |
| Mimistom Ltd | Health & social care | 2022 |
| Mini Hooves and Tails Limited | Arts & recreation | 2026 |
| Miniport Electric Ships Limited | Arts & recreation | 2016 |
| Mirada Films Ltd | Information & communication | 2022 |
| Mistline Capital Ltd | Construction | 2014 |
| MJW Building and Maintenance Limited | Construction | 2014 |
| MMO Corporate Investments Limited | Financial services | 2019 |
| MMO Limited | Professional & scientific | 2001 |
| Morbuild Ltd | Construction | 2018 |
| Morgans Partnership Ltd | Professional & scientific | 2014 |
| Moss and Co (Direct Accounts) Limited | Professional & scientific | 2010 |
| Mozzy Sails Ltd | Information & communication | 2025 |
| MRL Project Developments Limited | Information & communication | 2008 |
| MTS Enterprise Ltd | Wholesale & retail | 2026 |
| Muirheadspv Limited | Manufacturing | 2024 |
| N J Webb Properties Limited | Real estate | 2025 |
| N K Growns Electrical Limited | Construction | 2019 |
| Nakedfish Ventures Limited | Professional & scientific | 2018 |
| Nash Property Specialists Ltd | Real estate | 2020 |
| Nathan Page Travel Ltd | Administrative & support | 2026 |
| Nature Data Solutions Ltd | Professional & scientific | 2025 |
| Neal Smith Ltd | Real estate | 2007 |
| Neat Nails Ltd | Professional & scientific | 2010 |
| Network Red Limited | Information & communication | 2000 |
| Neurora Escapes Ltd | Administrative & support | 2025 |
| New Marine Flats Management Limited | Households | 2002 |
| New Road SPV 1 Limited | Real estate | 2024 |
| Newcombe Homes Limited | Real estate | 2010 |
| Nexorin Software Limited | Information & communication | 2026 |
| Next Sector Ltd | Arts & recreation | 2026 |
| Nexwave Technologies Limited | Information & communication | 2024 |
| Noahs RC ARK Limited | Wholesale & retail | 2020 |
| Norrads Consulting Ltd | Professional & scientific | 2021 |
| North Shore Technology Ltd | Information & communication | 2025 |
| North Street Dental Practice Limited | Health & social care | 2010 |
| Northney Dairy Limited | Manufacturing | 2009 |
| Northney Farm Tea Room Limited | Hospitality | 2016 |
| Northshore Metal Profiles Ltd | Manufacturing | 2021 |
| Novium Construction Limited | Construction | 2015 |
| Nrlawrence Limited | Information & communication | 2025 |
| Nutbourne Park Services Limited | Administrative & support | 1998 |
| Oakia Limited | Real estate | 2020 |
| Oakwood Hampshire Limited | Professional & scientific | 2009 |
| Oakwood Hideaways Limited | Hospitality | 2023 |
| Oakwood Ventures Limited | Construction | 2024 |
| Oakwood West Enterprises Limited | Construction | 2020 |
| Oakwood West Leisure Limited | Hospitality | 2021 |
| Oakwood West Tourism Limited | Hospitality | 2021 |
| October Consultancy Limited | Professional & scientific | 2021 |
| Odyssey Systems Group Ltd | Professional & scientific | 2025 |
| Oilfield Consultants International Ltd | Mining & quarrying | 1990 |
| Oilfield Valuation Consultants LLP | | 2012 |
| OKO Digital Limited | Information & communication | 1999 |
| Olicia Holdings Limited | Real estate | 2019 |
| OMG Properties Limited | Real estate | 2017 |
| Onsite Insights Limited | Professional & scientific | 2004 |
| Oplk Ltd | Real estate | 2026 |
| Orielle Homes Ltd | Real estate | 2025 |
| Osiers Farm Limited | Hospitality | 2021 |
| Osmech Pipework Ltd | Construction | 2011 |
| Oven Campsite Limited | Real estate | 2003 |
| Overstrand Views Management Co Ltd | Real estate | 2015 |
| Oxymoron by Design Ltd | Wholesale & retail | 2023 |
| P. M. Leisure Homes Limited | Hospitality | 1987 |
| Page Safety Ltd | Professional & scientific | 2013 |
| Palmerston HI Ltd | Households | 2023 |
| Pampered Paws by Carol Limited | Other services | 2018 |
| Panic Media Ltd | Information & communication | 2017 |
| Panimax Corporation Limited | Manufacturing | 2008 |
| Panimax Electric Ltd. | Wholesale & retail | 2008 |
| Panimax Marine Limited | Manufacturing | 2008 |
| Papyrus Medical Consultancy Ltd | Professional & scientific | 2013 |
| Papyrus Therapeutics UK Ltd | Professional & scientific | 2026 |
| Parkland Housing Limited | Real estate | 2022 |
| Parney Property Holdings I Limited | Households | 2022 |
| Partner-It Business Solutions Ltd | Information & communication | 2016 |
| Partner-It Consultancy Limited | Real estate | 2001 |
| Pathway Europe Limited | Administrative & support | 2009 |
| Paul Lewis Mobile Repairs LLP | | 2017 |
| Pcfe Ltd | Construction | 2020 |
| Pearsonics Limited | Professional & scientific | 2003 |
| Pebble Court Residents Company Limited | Administrative & support | 2000 |
| Peerage Limited | Real estate | 1996 |
| Pegas IOW Ltd | Hospitality | 2025 |
| Penguin Engineering Limited | Wholesale & retail | 1982 |
| Penrose Properties Ltd | Real estate | 2019 |
| Pete Bliss Industries Ltd | Arts & recreation | 2023 |