| Post a Ghost Ltd | Wholesale & retail | 2025 |
| Post Barn Stores Ltd | Wholesale & retail | 2024 |
| Postbox Ltd | Information & communication | 2014 |
| Postpulse Analytics Limited | Information & communication | 2025 |
| Potential Works Limited | Administrative & support | 2026 |
| Potts Financial Training LLP | | 2014 |
| Poulette Ltd | Wholesale & retail | 2026 |
| Pourfection Ltd | Hospitality | 2022 |
| POW POW Events Limited | Professional & scientific | 2014 |
| Powder Arts Thermography Warehouse Limited | Wholesale & retail | 2005 |
| Power Infrastructure Ltd | Professional & scientific | 2024 |
| Powerhouse Media Ltd | Information & communication | 2018 |
| Powerhouse Systems Limited | Other services | 2019 |
| Poynter Construction Limited | Construction | 2020 |
| Ppdsv Ltd | Financial services | 2025 |
| Ppgh Opco Ltd | Professional & scientific | 2023 |
| Practical Change Partners Limited | Administrative & support | 2019 |
| Practical Property DEV Ltd | Construction | 2025 |
| Practice Tech Ltd | Information & communication | 2015 |
| Pragma Exfi LLP | | 2021 |
| Praktical Solutions Ltd | Professional & scientific | 2019 |
| Praktika Limited | Information & communication | 2025 |
| Pramah Ltd | Wholesale & retail | 2021 |
| Pramstrad Ltd | Wholesale & retail | 2020 |
| Pranaksh Properties Ltd | Real estate | 2025 |
| PRATTS3DPRINTING Ltd | Manufacturing | 2026 |
| Praxis Technology Ltd | Information & communication | 2026 |
| Prayosha Holdings Limited | Real estate | 2020 |
| Prayosha Properties Limited | Construction | 2004 |
| Precision Post Production Limited | Information & communication | 2017 |
| Precision Talent Ltd | Administrative & support | 2015 |
| Predator Motorsport Ltd | Wholesale & retail | 2001 |
| Preetcox Ltd | Arts & recreation | 2022 |
| Preframe Ltd | Professional & scientific | 2026 |
| Premier Controls Limited | Manufacturing | 2010 |
| Premier HOP Limited | Wholesale & retail | 2020 |
| Premier Oak Property Management Ltd | Real estate | 2024 |
| Premier Plastics Windows Limited | Construction | 2013 |
| Premium Pubb Co Ltd | Hospitality | 2012 |
| Prenohq Ltd | Information & communication | 2022 |
| Prepper Spray Ltd | Construction | 2025 |
| Preservicesuk Ltd | Construction | 2025 |
| Prestige Carpet Care Ltd | Administrative & support | 2014 |
| Prestige Management Group Ltd | Real estate | 2022 |
| Prestige Renovations (ST Albans) Limited | Construction | 2023 |
| Prestigious DRY Cleaners Ltd | Manufacturing | 2025 |
| Prestigious DRY Cleaning Ltd | Other services | 2013 |
| Prestives Ltd | Wholesale & retail | 2025 |
| Pretium Frameworks Limited | Administrative & support | 2015 |
| Priash Properties Limited | Real estate | 2026 |
| Price Gardner Services Consultants Limited | Construction | 1996 |
| Priceblick Ltd | Information & communication | 2015 |
| Priceco Ltd | Transport & logistics | 2021 |
| Pride & Joy Ltd | Construction | 2026 |
| Pride Property Maintenance Herts Limited | Other services | 2019 |
| Priferential Accessories Limited | Manufacturing | 2015 |
| Prima Materia Ltd | Agriculture & fishing | 2017 |
| Prime Agriculture Investments Limited | Agriculture & fishing | 2021 |
| Prime Facilities Services Ltd | Administrative & support | 2022 |
| Prime Family Holdings LLP | | 2023 |
| Prime Logic Data Ltd | Information & communication | 2026 |
| Prime Pace Products Limited | Wholesale & retail | 2011 |
| Prime Progression Academy Ltd | Education | 2025 |
| Prime Trading Group (UK) Ltd | Financial services | 2022 |
| Prime Workforce Solutions Ltd | Administrative & support | 2022 |
| Primelawn Ltd | Administrative & support | 2025 |
| Primenet Marketing Limited | Administrative & support | 2005 |
| Primenet Ventures Limited | Professional & scientific | 2003 |
| Primera Capital Ltd | Real estate | 2021 |
| Primera Technology Limited | Professional & scientific | 2004 |
| Primetech Electrical Solutions Ltd | Construction | 2025 |
| Primrose Hill Nannies Ltd | Other services | 2020 |
| Principal Edge Limited | Professional & scientific | 2026 |
| Print and Web Shop Ltd | Manufacturing | 2012 |
| Prism Digital Ventures Limited | Information & communication | 2026 |
| Prisma Energy Ltd | Manufacturing | 2012 |
| Prisma Investments Ltd | Real estate | 2021 |
| Pristine Steam Cleaning Limited | Administrative & support | 2024 |
| Pritchards Heating and Plumbing Limited | Construction | 2020 |
| Privacy Shift Ltd | Information & communication | 2025 |
| Private & Commercial Lifetime Partners Limited | Financial services | 2004 |
| Privateer Pictures Ltd | Information & communication | 1997 |
| Pro Sports Teamwear Limited | Wholesale & retail | 2023 |
| Pro-Med Surgical Limited | Health & social care | 2014 |
| Procurement for Export Limited | Administrative & support | 1999 |
| Procurement Labs Ltd | Professional & scientific | 2025 |
| Procurewise Consulting Ltd | Professional & scientific | 2026 |
| Prodata Recruitment Limited | Other services | 2018 |
| Prodigy Property Partners Ltd | Construction | 2026 |
| Product Consulting Ltd | Professional & scientific | 2023 |
| Product Factory for Startups Limited | Professional & scientific | 2011 |
| Product Seed Software Limited | Information & communication | 2025 |
| Professional Association for Childcare and Early Years | Education | 1986 |
| Professional Financial Centre (Thames Valley) Ltd | Financial services | 2001 |
| Professional Profits Ltd | Education | 2024 |
| Profit Systems Group Ltd | Administrative & support | 2025 |
| Profoil Systems Limited | Manufacturing | 2010 |
| Proform Mechanical Ltd | Construction | 2022 |
| Profound Building Solutions Ltd | Construction | 2014 |
| Progressive IT Solutions Ltd | Information & communication | 2023 |