| Priwater Property Management Limited | Households | 2005 |
| Prizer Limited | Real estate | 1985 |
| Pro Construction London Limited | Administrative & support | 2011 |
| Pro Control Systems Ltd | Professional & scientific | 2018 |
| Pro D I Plumbing Limited | Construction | 2025 |
| Pro HNS Ltd | Wholesale & retail | 2021 |
| Pro Window Cleaning Ltd | Administrative & support | 2007 |
| Probuild Maintenance Ltd | Construction | 2026 |
| Process Control Simulation and Modelling Limited | Professional & scientific | 2019 |
| Procorr Limited | Professional & scientific | 2018 |
| Prodent Investments Limited | Real estate | 2024 |
| Prodor Door Republic Ltd | Construction | 2024 |
| Produced Where Ltd | Information & communication | 2023 |
| Profectum Limited | Professional & scientific | 2014 |
| Profedone Ltd | Administrative & support | 2022 |
| Profeet Podiatry Limited | Health & social care | 2011 |
| Professional Cleaning and Support Ltd | Health & social care | 2015 |
| Professional Construction Services London Limited | Extraterritorial | 2014 |
| Professional Occupational Medical Services Ltd | Health & social care | 2020 |
| Professor Lesley Regan Ltd | Financial services | 2011 |
| Profix London Ltd | Wholesale & retail | 2021 |
| Profix Motors Ltd | Wholesale & retail | 2025 |
| Proform Build Ltd | Construction | 2023 |
| Progem Properties Ltd | Real estate | 2020 |
| Progress Park Properties Ltd | Real estate | 2014 |
| Project 218 Ltd | Real estate | 2021 |
| Project 3179 Limited | Professional & scientific | 2023 |
| Project Afrique Limited | Other services | 2015 |
| Project Management Consulting Services UK Ltd | Construction | 2025 |
| Prokleen London Limited | Other services | 2024 |
| Prolan Services Limited | Professional & scientific | 2022 |
| Prolific Coaching Ltd | Education | 2025 |
| Prometheus Training Ltd | Administrative & support | 2016 |
| Promikia Ltd | Transport & logistics | 2020 |
| Propease Management Ltd | Households | 2025 |
| Proper Builders and Contractors Ltd | Construction | 2024 |
| PROPERTIES47 Ltd | Real estate | 2022 |
| PROPERTIES4DEMAND Limited | Hospitality | 2023 |
| Property Hive Network Limited | Financial services | 2022 |
| Property Plans Limited | Real estate | 2003 |
| Property Vineyard Services Ltd | Real estate | 2024 |
| PROPM8 Ltd | Administrative & support | 2026 |
| Propsquare UK Ltd | Real estate | 2010 |
| Proptea Limited | Real estate | 2018 |
| Propzilla Services Ltd | Administrative & support | 2026 |
| Prospect Consultancy Limited | Professional & scientific | 2015 |
| Prospect Developments (London) Limited | Construction | 2013 |
| Prosperitas Enterprises Ltd | Wholesale & retail | 2024 |
| Prosperity Address Limited | Construction | 2021 |
| Prosperpoint Health Ltd | Health & social care | 2025 |
| Protect Fire Ltd | Construction | 2010 |
| Protocol Financial Consulting Limited | Financial services | 2014 |
| Protocol Healthcare Services Ltd | Health & social care | 2016 |
| Protovox Limited | Professional & scientific | 2015 |
| Provenguild Limited | Administrative & support | 1987 |
| Prowse Avenue Management Company Limited | Households | 2006 |
| Proxytech Ltd | Information & communication | 2023 |
| Prudential Impex PVT Ltd | Administrative & support | 2010 |
| PSB TM Services Limited | Transport & logistics | 2025 |
| PSP Gorasia Estate Ltd | Real estate | 2024 |
| PST Projects Limited | Professional & scientific | 2014 |
| Psycho Tropical Ltd | Other services | 2018 |
| Public EYE Technologies Ltd | Manufacturing | 2011 |
| Publicity Overload Limited | Professional & scientific | 2002 |
| Publish Narrative Ltd | Wholesale & retail | 2024 |
| Puggles Media Limited | Arts & recreation | 2019 |
| Puja Silk House Limited | Wholesale & retail | 1998 |
| Pukkka Cleaning Ltd | Administrative & support | 2025 |
| Punch London Limited | Arts & recreation | 2019 |
| Punto Properties Ltd | Real estate | 2021 |
| Pupae Ltd | Wholesale & retail | 2026 |
| Pupsik Limited | Administrative & support | 2019 |
| Purcell Business and Accounting Services Ltd | Professional & scientific | 2017 |
| Pure Accountants LLP | | 2013 |
| Pure Analysis Consulting Limited | Information & communication | 2017 |
| Pure Analysis Developments Limited | Real estate | 2021 |
| Pure Clean Carpet & Sofa Cleaning Ltd | Administrative & support | 2026 |
| Pure Gifts Ltd | Wholesale & retail | 2026 |
| Pure IT Systems Limited | Information & communication | 2025 |
| Pure View Limited | Administrative & support | 2019 |
| Purecure Living Ltd | Wholesale & retail | 2025 |
| Pureleafs LDN Ltd | Hospitality | 2025 |
| Purity HS Limited | Health & social care | 2020 |
| Purp Limited | Real estate | 2018 |
| Purple Plumbing & GAS Limited | Construction | 2014 |
| Puvy Healthcare Ltd | Health & social care | 2019 |
| Puzzle Construction London Ltd | Construction | 2026 |
| PVA Solutions Group Ltd | Energy | 2026 |
| Pyramid Exports Limited | Wholesale & retail | 1986 |
| Pyramid Foods Ltd. | Hospitality | 2016 |
| Pyramid Lounge Limited | Hospitality | 2023 |
| Pzeg Limited | Hospitality | 2025 |
| QAF Consulting Ltd | Professional & scientific | 2024 |
| Qbit Security Ltd | Wholesale & retail | 2026 |
| Qfor Ltd | Wholesale & retail | 2026 |
| QH (Chartridge) Limited | Construction | 2020 |
| QH (Langley) Limited | Construction | 2024 |
| QH (London Colney) Limited | Construction | 2019 |
| QH (Milebarn) Limited | Construction | 2025 |
| QH (Northchurch) Limited | Construction | 2021 |