| Procesa UK Limited | Information & communication | 2003 |
| Prochida Limited | Financial services | 2020 |
| Proctor Investments Limited | Real estate | 2016 |
| Procula Limited | Information & communication | 1991 |
| Procure MED Ltd | Professional & scientific | 2019 |
| Procureum Limited | Professional & scientific | 2020 |
| Product Leader Ltd | Information & communication | 2019 |
| Production Ready AI Ltd | Information & communication | 2023 |
| Production-Designer Limited | Information & communication | 2020 |
| Productive Technology Limited | Information & communication | 1999 |
| Productlife Limited | Professional & scientific | 2005 |
| Professional Dwellings Ltd | Real estate | 2018 |
| Professional Outsource Contracts Limited | Professional & scientific | 2012 |
| Profitech Electromechanics Ltd | Manufacturing | 2024 |
| Profitmore Limited | Administrative & support | 2004 |
| Profone Laboratories (UK) Limited | Manufacturing | 2023 |
| Proformance Health & Fitness Ltd | Arts & recreation | 2026 |
| Profser Ltd | Manufacturing | 2025 |
| Proglow Professional Tanning Limited | Other services | 2013 |
| Progress Cleaning Limited | Administrative & support | 2012 |
| Progressive Aesthetics Ltd | Other services | 2022 |
| Progressive Printing & Prototyping Ltd | Manufacturing | 2024 |
| Project Cambridge Ltd | Professional & scientific | 2025 |
| Project Marketing Company Limited | Professional & scientific | 2010 |
| Project Moonraker Ltd. | Administrative & support | 2019 |
| Project Skyfall Ltd | Wholesale & retail | 2026 |
| Project Solution Ltd | Information & communication | 2003 |
| Project Spectre Ltd | Wholesale & retail | 2024 |
| PROJECT83 Group Ltd | Professional & scientific | 2017 |
| Projectfireengine C.I.C. | Education | 2026 |
| Projecthaus Labs Ltd | Information & communication | 2026 |
| Projectway Property Management Limited | Households | 1991 |
| Promax Safety Co., Ltd | Extraterritorial | 2015 |
| Promaxima Ltd | Information & communication | 2024 |
| Prominent Ventures UK Ltd | Health & social care | 2016 |
| Promir Limited | Construction | 2011 |
| Promowater Ltd | Wholesale & retail | 2021 |
| Prompt Build Ltd | Construction | 2024 |
| Prompt Electrical Limited | Administrative & support | 2016 |
| Pronovotech Limited | Professional & scientific | 2006 |
| Proof-Reading-Service.Com Ltd | Education | 2013 |
| Propdoc Limited | Real estate | 2000 |
| Proper Tree Property Ltd | Real estate | 2023 |
| Properties PS Ltd | Real estate | 2020 |
| Propertissimo Ltd | Information & communication | 2011 |
| Property & Land Consultancy Services LLP | | 2020 |
| Property Empire Construction & Maintenance Ltd | Wholesale & retail | 2019 |
| Property Feeds Limited | Information & communication | 2022 |
| Property in 12 Media Ltd | Professional & scientific | 2021 |
| Property KOR Ltd | Real estate | 2021 |
| Property Rentals (Cambridge) Ltd | Real estate | 2020 |
| Property Repair Inspection Services Limited | Financial services | 2013 |
| Property Safety Ltd | Other services | 2023 |
| Property Solutions Cambridge Limited | Construction | 2023 |
| Propertymint Ltd | Real estate | 2019 |
| Propkey Ltd | Administrative & support | 2024 |
| Proportion Brewing and Blending Limited | Manufacturing | 2024 |
| Proposal Automation Limited | Information & communication | 2011 |
| Proppharm Ltd | Professional & scientific | 2018 |
| Proprop Ventures Ltd | Hospitality | 2024 |
| Proquest European Holdings Limited | Information & communication | 2013 |
| Proquest Information and Learning Limited | Information & communication | 1973 |
| Proquest Pension Trustee Company Limited | Information & communication | 2007 |
| Proquest UK Holdings Ltd | Information & communication | 1968 |
| Prosolution Ltd | Manufacturing | 2025 |
| Prospect Bloodstock Ltd | Agriculture & fishing | 2022 |
| Prospect Court (Management) Company Limited | Households | 1985 |
| Prospect Place (Windsor) RES. Assoc. Limited | Households | 1996 |
| Prospect Point Management Limited | Administrative & support | 2010 |
| Prospecthill International Ltd | Professional & scientific | 2020 |
| Prospectral Ltd | Professional & scientific | 2021 |
| Prosper Point UK Limited | Transport & logistics | 2025 |
| Prosper Thermal Company Limited | Manufacturing | 2018 |
| Prosperity Dragon Ltd | Wholesale & retail | 2026 |
| Prospernexus Ltd | Administrative & support | 2025 |
| Prostratex Ltd. | Professional & scientific | 2017 |
| Protahomes Ltd | Wholesale & retail | 2019 |
| Protavio Ltd | Professional & scientific | 2016 |
| Protean Wealth LLP | | 2012 |
| Protech Dynamics Ltd | Professional & scientific | 2025 |
| Protech Flow Solutions Ltd | Wholesale & retail | 2012 |
| Protechnic Properties Limited | Real estate | 2001 |
| Protechno Electronics Co., Ltd | Wholesale & retail | 2024 |
| Proteinlogic Limited | Professional & scientific | 2003 |
| Protem Marketing Resources Limited | Professional & scientific | 1999 |
| Proteotype Diagnostics Ltd | Professional & scientific | 2019 |
| Proteus Enterprise Limited | Real estate | 2022 |
| Protiomix Limited | Manufacturing | 2022 |
| Protogenia Consulting Ltd | Professional & scientific | 2009 |
| Protolaunch Ltd | Manufacturing | 2019 |
| Protoss Trading Company Limited | Wholesale & retail | 2025 |
| Protronics (Cambridge) Limited | Manufacturing | 2010 |
| Protu Technology Limited | Administrative & support | 2016 |
| Protus Limited | Real estate | 1990 |
| Proudman Law Limited | Professional & scientific | 2025 |
| Proverbs Home Improvements Limited | Administrative & support | 2021 |
| Providence Homeware Limited | Manufacturing | 2003 |
| PRP Optoelectronics Limited | Manufacturing | 1989 |
| Pruden Holdings Limited | Real estate | 2021 |
| Prudentia Health Group Limited | Financial services | 2025 |