| Prima 7 Limited | Transport & logistics | 2014 |
| Primal Building Services Ltd | Energy | 2024 |
| Primal Studios Ltd | Other services | 2023 |
| Primary Base 2000 Limited | Arts & recreation | 1998 |
| Primary Sports Developments Limited | Education | 2022 |
| Primate Planet Productions Ltd | Information & communication | 2006 |
| Prime Business Finance Ltd | Financial services | 2005 |
| Prime Delux Ltd | Wholesale & retail | 2022 |
| Prime Finish Solutions Ltd | Construction | 2024 |
| Prime Haven Estates Ltd | Real estate | 2025 |
| Prime Homes Southern Ltd | Real estate | 2022 |
| Prime Hospitality GP Ltd | Administrative & support | 2024 |
| Prime JET Ltd | Administrative & support | 2025 |
| Prime Leads (UK) Limited | Administrative & support | 2010 |
| Prime LET Homes Southampton Ltd | Real estate | 2026 |
| Prime Management (Hotels) Limited | Professional & scientific | 1990 |
| Prime Properties Southampton Limited | Real estate | 2020 |
| Prime Property Investors Limited | Real estate | 2018 |
| Prime Sports Hospitality Limited | Arts & recreation | 2023 |
| Prime Sweets Ltd | Other services | 2017 |
| Primea Studios Ltd | Manufacturing | 2026 |
| Primed Investments Ltd | Real estate | 2019 |
| Primeguard Workforce Management Ltd | Information & communication | 2025 |
| Primeharborix Construction Ltd Ltd | Professional & scientific | 2026 |
| Primenest Property Investment TR Ltd | Real estate | 2025 |
| Primevalue Cars Ltd | Wholesale & retail | 2026 |
| Primordial Clothing Ltd | Wholesale & retail | 2025 |
| Primrose Copse Dibden Limited | Real estate | 2004 |
| Prince Edgar ROW Management Company Limited | Households | 2000 |
| Princes Court Freeholders Limited | Households | 2000 |
| Princess Coaches Limited | Transport & logistics | 2000 |
| Princess Court Residents' Group Limited | Households | 1987 |
| Principal 3 Limited | Administrative & support | 2017 |
| Principal Business Services Ltd | Professional & scientific | 2022 |
| Principal Design Limited | Professional & scientific | 2014 |
| Principia Marine Engineering Supply Ltd | Wholesale & retail | 2026 |
| Print Snappy Limited | Manufacturing | 2025 |
| Printline Southampton (UK) Limited | Administrative & support | 1993 |
| Printworks Decorating Ltd | Construction | 2023 |
| Prior's Corner Residents Ltd | Households | 2021 |
| Priority Competitions Ltd | Arts & recreation | 2025 |
| Priority Cooling Ltd | Construction | 2012 |
| Priority One Engineering Services Ltd | Professional & scientific | 2015 |
| Priority Window Films and Coatings Limited | Construction | 2015 |
| Priory Court (Locksheath) NO. 1 Residents Company Limited | Professional & scientific | 1986 |
| Priory Court (Locksheath) NO. 3 Residents Company Limited | Households | 1989 |
| Priory School Management Company Limited | Households | 2000 |
| Prism Windows Limited | Manufacturing | 2012 |
| Prisma Studio Limited | Professional & scientific | 2022 |
| Prismia Limited | Administrative & support | 2018 |
| Prismio Ltd | Information & communication | 2022 |
| Pritchard Green Limited | Wholesale & retail | 2010 |
| Privagy Ltd | Professional & scientific | 2026 |
| Private Car Ltd | Transport & logistics | 2023 |
| Private Client Consultants Limited | Professional & scientific | 2019 |
| Private Parking Limited | Real estate | 2009 |
| Privately YOU Ltd | Wholesale & retail | 2025 |
| Privilege Drives & Landscaping Limited | Construction | 2022 |
| Priya TEW Limited | Health & social care | 2021 |
| PRL Smith Ltd | Financial services | 2015 |
| Pro Aesthetician Ltd | Other services | 2024 |
| Pro Autoworx Ltd | Wholesale & retail | 2024 |
| Pro Board Drylining Ltd | Construction | 2021 |
| Pro Corporation UK Ltd | Other services | 2024 |
| Pro Domo MEA Ukeig | | 2015 |
| Pro E Solutions Limited | Manufacturing | 2014 |
| Pro Futuro Sports LLP | | 2022 |
| Pro Glaze Windows Doors & Conservatories Limited | Construction | 2010 |
| Pro Heat 4 Ltd | Construction | 2023 |
| Pro Home Improvements Ltd | Construction | 2025 |
| Pro Life Cover Ltd | Financial services | 2016 |
| Pro Pitch Care Limited | Arts & recreation | 2024 |
| Pro Plus Solutions Ltd | Administrative & support | 2023 |
| Pro Spot Seller Ltd | Wholesale & retail | 2026 |
| Pro Staffing Solutions Ltd | Administrative & support | 2025 |
| Pro-Jet Solutions Ltd | Administrative & support | 2024 |
| Pro-R Ltd | Transport & logistics | 2016 |
| Pro-Reactive Engineering Ltd | Manufacturing | 2022 |
| Pro-Spec Coatings Ltd | Construction | 2022 |
| Proactium Consulting Ltd | Professional & scientific | 2014 |
| Proactive Communications Limited | Information & communication | 2000 |
| Probashi Ltd | Hospitality | 2015 |
| Procbox Limited | Administrative & support | 2014 |
| Process Products Direct Limited | Wholesale & retail | 2021 |
| Proclad and Roofing Ltd | Construction | 2026 |
| PROCOM365 Limited | Wholesale & retail | 2016 |
| Procurement Plus Ltd | Professional & scientific | 2022 |
| Procurement Support Services Transformation Limited | Professional & scientific | 2009 |
| Product Chain Limited | Administrative & support | 1991 |
| Product Data Group Ltd | Professional & scientific | 2011 |
| Product Sourcing Group Limited | Other services | 2022 |
| Production Hype Limited | Other services | 2017 |
| Production on Point Limited | Information & communication | 2020 |
| Proestetica Beauty Clinic Limited | Other services | 2018 |
| Prof Builders Limited | Construction | 2025 |
| Professional Detailing MVS Ltd | Wholesale & retail | 2021 |
| Professional Equipment Manufacturer Limited | Manufacturing | 2025 |
| Professional Garage Ltd | Wholesale & retail | 2020 |
| Professional PM Services Ltd | Financial services | 2012 |
| Professor’S Original Bubble Tea Ltd | Manufacturing | 2024 |