| Portugolfe Limited | Arts & recreation | 1997 |
| Postcard Wines Limited | Wholesale & retail | 2024 |
| Powell Cinema Engineers Ltd | Manufacturing | 2012 |
| Powell Consulting Solutions Limited | Professional & scientific | 2013 |
| Power Drive Drum Co. Limited (the) | Manufacturing | 1971 |
| Power TAN Limited | Wholesale & retail | 2023 |
| Powerlec Ltd | Construction | 2016 |
| Powervolt Ltd | Administrative & support | 2025 |
| PP (Cheshunt) Management Company Limited | Households | 2016 |
| PQP Operations Ltd | Professional & scientific | 2021 |
| PR36 Consultancy Ltd | Information & communication | 2023 |
| PR36 Ltd | Households | 2018 |
| Practicale Limited | Professional & scientific | 2013 |
| Pragmatic PMO Limited | Professional & scientific | 2011 |
| Pram Publications Ltd | Information & communication | 2025 |
| Praters of Hollingdon LLP | | 2008 |
| Pratt & Whitney Canada (UK) Limited | Wholesale & retail | 1997 |
| Praxis Surveying Limited | Professional & scientific | 2009 |
| Prbs Limited | Manufacturing | 2013 |
| PRD Stag Services Ltd | Information & communication | 2019 |
| Prebendal House Limited | Households | 2022 |
| Prebendal House Management Company Limited | Households | 2010 |
| Precision Films Ltd | Administrative & support | 2024 |
| Precision Flooring Group Ltd | Construction | 2026 |
| Premier Coffee Distributors Limited | Wholesale & retail | 2026 |
| Premier Smile Dental Excellence Ltd | Health & social care | 2024 |
| Premiere Animals Ltd | Financial services | 2026 |
| Prenoun Limited | Professional & scientific | 2003 |
| Prescott Contractor Services Limited | Information & communication | 2023 |
| Preservascan Limited | Transport & logistics | 2024 |
| President Barbers Limited | Other services | 2024 |
| Prestique Cleaning Ltd | Administrative & support | 2026 |
| Preston Global Ltd | Wholesale & retail | 2026 |
| Prewcrew Ltd | Administrative & support | 2019 |
| Prideaux People Ltd | Professional & scientific | 2018 |
| Priestgill Ltd | Financial services | 2025 |
| Primary P.E. Planning Limited | Education | 2016 |
| Prime Place Moberly Management Company Limited | Real estate | 2016 |
| Prime Tax Solutions Ltd | Professional & scientific | 2022 |
| Primeway Home Solutions Ltd | Construction | 2026 |
| Primrose Gardens (Leighton Buzzard) Management Limited | Households | 2007 |
| Primrose Heights Management Company Limited | Households | 2008 |
| Print AS Seen Ltd | Wholesale & retail | 2025 |
| Priority Plumbing Services Limited | Construction | 2024 |
| Priory Records Limited | Information & communication | 1997 |
| Prism Laser Services Ltd | Extraterritorial | 2021 |
| Private Carers Ltd | Administrative & support | 2024 |
| Pro Access Scaffolding Limited | Construction | 2006 |
| Pro Drywall Finishing Limited | Construction | 2014 |
| Pro Fitness Solutions Ltd | Health & social care | 2008 |
| Pro Floor Sanding Ltd | Construction | 2025 |
| Pro Jockey Limited | Arts & recreation | 2021 |
| Pro Project Group Ltd | Manufacturing | 2026 |
| Pro Spaces Group Ltd | Construction | 2025 |
| Pro-Fix Building & Property Maintenance Limited | Construction | 2014 |
| Proactive Hire Ltd | Extraterritorial | 2006 |
| Proactive Instruments Limited | Extraterritorial | 2010 |
| Proactive Property Management Ltd | Real estate | 2024 |
| Proactive Test Ltd | Extraterritorial | 2006 |
| Proactive Test Solutions Limited | Professional & scientific | 2003 |
| Probert Electrical Ltd | Construction | 2018 |
| Procedural Thinking Ltd | Information & communication | 2026 |
| Procurement Connextions Ltd | Information & communication | 2025 |
| Procuretek Limited | Professional & scientific | 2015 |
| Prodec Quality Painting & Decorating Ltd | Construction | 2022 |
| Prodtech Strategy & Management Ltd | Professional & scientific | 2025 |
| Professional People Limited | Professional & scientific | 1993 |
| Profit Cash Growth Ltd | Administrative & support | 2020 |
| Prohealth Consultants Ltd | Health & social care | 2024 |
| Project Connextions Ltd | Information & communication | 2025 |
| Projects and Print Limited | Professional & scientific | 2010 |
| Projects and Property Holdings Limited | Real estate | 2017 |
| Projects and Signs Limited | Professional & scientific | 2016 |
| Prologics Europe Limited | Wholesale & retail | 2010 |
| Promediait Ltd | Information & communication | 2025 |
| Propel Energy Limited | Wholesale & retail | 2022 |
| Property Marketing Platform Limited | Information & communication | 2022 |
| Propertywide Limited | Professional & scientific | 2004 |
| Prophetele Marketing Ltd | Information & communication | 2012 |
| Prosser Management Limited | Professional & scientific | 2013 |
| Protection Helpline Limited | Extraterritorial | 2015 |
| Prototype & Developments Ltd | Manufacturing | 2019 |
| Provail AI Limited | Information & communication | 2026 |
| Prpr Limited | Administrative & support | 2019 |
| PTO Climate Control LLP | | 2013 |
| Puff a Land Ltd | Wholesale & retail | 2026 |
| Pullan Enterprise Ltd | Wholesale & retail | 2025 |
| Pullan Property Group Limited | Construction | 2025 |
| Pullum Sports Ltd. | Manufacturing | 2005 |
| Pulse Fulfilment Solutions Limited | Transport & logistics | 2026 |
| Punctilio Consulting Limited | Professional & scientific | 2024 |
| Puppi Dog Toys Ltd | Manufacturing | 1999 |
| Purdess People Limited | Administrative & support | 2025 |
| Purelee Electrical Ltd | Construction | 2021 |
| Purpose Works Limited | Professional & scientific | 2017 |
| PUT HAT Ltd | Professional & scientific | 2026 |
| Pynford Piling Services Limited | Other services | 2004 |
| Q Solutions & Sons Limited | Other services | 2021 |
| Q&A Financial Solutions LLP | | 2012 |
| Q-Build LB Limited | Construction | 2023 |