| PM ERP Consulting Limited | Information & communication | 2026 |
| PMH Management Ltd | Construction | 2018 |
| PMQ Consultancy Ltd | Professional & scientific | 2025 |
| PNF Developments Limited | Real estate | 2025 |
| PNM Traders Ltd | Wholesale & retail | 2024 |
| Pnpw Enterprises Limited | Administrative & support | 2019 |
| Pocock Roses Ltd | Wholesale & retail | 2014 |
| Pococks Absolute Rose Ltd | Wholesale & retail | 2015 |
| Point Blank Simulator UK Limited | Information & communication | 2019 |
| Point Polzeath Management Co Ltd | Households | 2012 |
| Poisongreen Investments Ltd | Information & communication | 2019 |
| Polar Recruitment Services Limited | Administrative & support | 2008 |
| Polar Toes Limited | Administrative & support | 2017 |
| Polar Umbrella Limited | Administrative & support | 2012 |
| Polaris Consulting Limited | Professional & scientific | 2023 |
| Polestar Technologies Limited | Manufacturing | 2013 |
| Pollard (Hampshire) Limited | Professional & scientific | 2011 |
| Polygon Property Maintenance Limited | Construction | 2020 |
| Polygon Property Management Limited | Real estate | 2003 |
| Polytile Limited | Real estate | 2006 |
| Polzeath ASH Limited | Administrative & support | 2017 |
| Ponder Yonder Limited | Real estate | 2021 |
| Pondero Limited | Extraterritorial | 2016 |
| Poolemead Accountants (Winchester) Ltd | Professional & scientific | 2012 |
| Poolharry Farms Limited | Agriculture & fishing | 2025 |
| POP Mutant Films Limited | Information & communication | 2015 |
| Portals for People Ltd | Information & communication | 2025 |
| Portchester Equity Limited | Professional & scientific | 2022 |
| Portcullis Hotel Asset Management Limited | Other services | 2020 |
| Portcullis Hotel Investment Ltd | Other services | 2010 |
| Portdex Money Limited | Manufacturing | 2020 |
| Porteous Engineering Limited | Professional & scientific | 2025 |
| Portfolio Design Ltd | Professional & scientific | 2000 |
| Portionpass Ltd | Administrative & support | 2026 |
| Portlet Consulting Limited | Professional & scientific | 2025 |
| Portobello Limited | Agriculture & fishing | 2016 |
| Poseidon 404 Limited | Construction | 2013 |
| Posh Wash Winchester Ltd | Other services | 2019 |
| Positive Difference Life Limited | Other services | 2020 |
| Positive Space Limited | Construction | 1998 |
| Pots Holdings Limited | Manufacturing | 2008 |
| Potters Accounting Services Limited | Professional & scientific | 2019 |
| PPJ Holdings Ltd | Real estate | 2024 |
| PQR100 Limited | Real estate | 2019 |
| PR0J3C7T0DD Ltd | Information & communication | 2022 |
| Precisive Solutions Ltd | Professional & scientific | 2019 |
| Premier Home Improvements (Berkshire) Limited | Construction | 2023 |
| Premium IV Limited | Administrative & support | 2011 |
| Presentia Young & Co Limited | Professional & scientific | 1969 |
| Preshaw Down Ltd | Administrative & support | 2011 |
| Press Freedom Project Limited | Professional & scientific | 2025 |
| Press Pause Yoga Retreats Limited | Other services | 2022 |
| Prestige Properties (Southern) Limited | Real estate | 2015 |
| Preston Air Services Limited | Professional & scientific | 2024 |
| Preston Candover Developments Ltd | Construction | 2024 |
| Pretorian Welfare Security Group Ltd | Administrative & support | 2026 |
| Prevision Consultants Limited | Professional & scientific | 2003 |
| Priapus Gardens & Landscapes Ltd | Administrative & support | 2023 |
| Primary Care Matters Limited | Professional & scientific | 1999 |
| Primaxial Database Dynamics Ltd | Information & communication | 2001 |
| Prime Cars Winchester Limited | Transport & logistics | 2025 |
| Primeworks Limited | Construction | 2025 |
| Primex Nutrition Limited | Wholesale & retail | 2026 |
| Primrose (2013) Limited | Health & social care | 1999 |
| Primrose NO.1 Limited | Administrative & support | 2009 |
| Princess Court (Winchester) Management Company Limited | Households | 2011 |
| Princess Louise Management Company Limited | Households | 2009 |
| Princess Louise Square Management Company Limited | Households | 2004 |
| Pringle Reclaim Ltd | Water & waste | 2020 |
| Printed Originals Ltd | Arts & recreation | 2019 |
| Priom Ltd | Wholesale & retail | 2019 |
| Prior's Orchard Management Company Limited | Households | 2018 |
| Prism Consulting Group Ltd | Professional & scientific | 2025 |
| Prismic Creative Supplies Ltd | Wholesale & retail | 2026 |
| Pristine JET Clean Ltd | Administrative & support | 2025 |
| Private Medical Consultants Ltd | Health & social care | 2025 |
| Pro Flight Aviation Ltd | Professional & scientific | 2013 |
| Proaction HR Ltd | Administrative & support | 2011 |
| Proaction Training Ltd | Administrative & support | 2020 |
| Process Driven Design Limited | Professional & scientific | 1999 |
| Professional Circuit Designs Limited | Professional & scientific | 1997 |
| Professional Tree Services Limited | Agriculture & fishing | 1994 |
| Profitprophet Limited | Administrative & support | 1998 |
| Profolio Ltd | Professional & scientific | 2023 |
| Progress Property Portfolio Ltd | Real estate | 2024 |
| Project & Contract Management Limited | Professional & scientific | 2020 |
| Project & Service Delivery Consulting Ltd | Professional & scientific | 2014 |
| Project B Management Limited | Professional & scientific | 2013 |
| Project Casa Limited | Construction | 2015 |
| Project Joy Ltd | Real estate | 2021 |
| Project Palms Limited | Wholesale & retail | 2017 |
| Project Secret Santa CIC | Health & social care | 2026 |
| Project Underscore Limited | Information & communication | 2023 |
| Project X by Sweat Limited | Education | 2019 |
| Projects for Profit Limited | Professional & scientific | 2003 |
| Projectsthat.Work Ltd | Information & communication | 2021 |
| Prop Management Limited | Real estate | 2010 |
| Propardis Limited | Professional & scientific | 2013 |
| Propelle Tech Ltd | Wholesale & retail | 2025 |
| Properties of Eden Limited | Real estate | 2026 |