| Phloonline Limited | Professional & scientific | 2022 |
| Phoenix Cameras Ltd | Information & communication | 2012 |
| Phoenix Consulting HF LLP | | 2021 |
| Phoenix Court Limited | Households | 2008 |
| Phoenix Football Academy Ltd | Arts & recreation | 2019 |
| Phoenix Football Academy Tours Limited | Administrative & support | 2019 |
| Phonetic Systems Ltd | Information & communication | 2026 |
| Photographic Memory Limited | Administrative & support | 2009 |
| Phraktion Limited | Professional & scientific | 2023 |
| Phta Consulting Ltd | Professional & scientific | 2024 |
| Phystus Limited | Information & communication | 2006 |
| Phytomed Ltd | Wholesale & retail | 2023 |
| PI Marketing Solutions Ltd | Professional & scientific | 2020 |
| PIC Vent Engineering Limited | Administrative & support | 2012 |
| Piccolo Arco Limited | Hospitality | 2014 |
| Pieniazek Consulting Limited | Transport & logistics | 2013 |
| Pierdell Construction Limited | Construction | 2014 |
| Pierre LE Pennec Consulting Ltd | Administrative & support | 2021 |
| Pike Holdings Limited | Financial services | 2023 |
| Pike Wood Sang Limited | Real estate | 2019 |
| Pikku Mobile Limited | Wholesale & retail | 2026 |
| Pilleyful Ltd | Information & communication | 2021 |
| Pine&Stone Ltd | Real estate | 2025 |
| Pinewood Gymnastics Club Limited | Arts & recreation | 2011 |
| Pinewood Miniature Railway Society Limited | Arts & recreation | 2003 |
| Pinewood Place Residents Management Company Limited | Households | 2006 |
| Ping Enterprises Ltd | Administrative & support | 2019 |
| Pink Buzz Limited | Administrative & support | 2010 |
| Pink Carnation Ltd | Wholesale & retail | 2016 |
| Pioneer Childcare Limited | Education | 2012 |
| Pioneers Natural Products Ltd | Manufacturing | 2023 |
| Pipers Field Management Company Limited | Households | 1999 |
| Pivotec Ltd | Information & communication | 2012 |
| Pixel JAM Ltd | Professional & scientific | 2019 |
| Pixelcore LLP | | 2025 |
| Pj's Lawncare+ Limited | Administrative & support | 2018 |
| PJC Surgical Care Ltd | Health & social care | 2026 |
| PJM Roofing Southern Ltd | Construction | 2014 |
| Pjmc Consulting Ltd | Information & communication | 2009 |
| PJT Marine Ltd | Manufacturing | 2025 |
| Placed Recruitment Limited | Information & communication | 2015 |
| Plaiground Ltd | Information & communication | 2025 |
| Planeterf Limited | Manufacturing | 2020 |
| Platform YP Limited | Education | 2022 |
| Platinum Leisure Limited | Financial services | 2022 |
| Platinum Singh Investments Ltd | Real estate | 2020 |
| Plaustein Limited | Construction | 2016 |
| Plexstore Limited | Wholesale & retail | 2024 |
| Plumbingit Limited | Construction | 2002 |
| Pluralyx Ltd | Information & communication | 2025 |
| Plus SUM Limited | Professional & scientific | 2012 |
| Plus Three Nurseries Ltd | Education | 2017 |
| Plymouth Health Limited | Health & social care | 2023 |
| PM Real Estate Holdings Ltd | Real estate | 2021 |
| Pmkh Ltd | Information & communication | 2025 |
| Point Blanc Solutions Ltd | Professional & scientific | 2017 |
| Point Blank Solutions Limited | Professional & scientific | 2009 |
| Point of View Consulting Limited | Professional & scientific | 2024 |
| Pointer Systems Limited | Information & communication | 1997 |
| Poison and Petals Ltd | Wholesale & retail | 2026 |
| Polwins Limited | Health & social care | 2025 |
| Polydemon Solutions & Services Ltd | Information & communication | 2024 |
| Polygonum Limited | Administrative & support | 1977 |
| Polyphemus Productions Limited | Information & communication | 2014 |
| Pond House (Chertsey) Management Company Limited | Real estate | 2001 |
| Pondicherry Services Limited | Professional & scientific | 2016 |
| Pony Express Ltd | Other services | 2021 |
| POP Music Productions Ltd | Information & communication | 2025 |
| POP UP MD Ltd | Health & social care | 2023 |
| Popa Architecture Limited | Professional & scientific | 2016 |
| Popart Digital Ltd | Wholesale & retail | 2020 |
| Popham Management Services Ltd | Real estate | 2009 |
| Poppy Place Residents Company Limited | Households | 1994 |
| Pops & FLO Ltd | Wholesale & retail | 2023 |
| Popup Mainframe Ltd | Information & communication | 2021 |
| Porcelain Tiles Direct Limited | Wholesale & retail | 2021 |
| Porchester (South Ascot) Residents Association Limited | Households | 1982 |
| Port Mile Leisure Limited | Hospitality | 2022 |
| Portable GAS Limited | Wholesale & retail | 2015 |
| Portal S.A. | | 1985 |
| Porter & Co Holdings Ltd | Financial services | 2022 |
| Porter & Harris Limited | Extraterritorial | 1977 |
| Porth Consulting Services Limited | Information & communication | 2008 |
| Posfin Capital (Reading) Limited | Wholesale & retail | 2021 |
| Positiva Limited | Real estate | 2003 |
| Positive Path Fitness Ltd | Other services | 2025 |
| Post Modern Soap Company Limited | Extraterritorial | 2022 |
| Poster Print & Design Limited | Manufacturing | 2000 |
| Pottery Pals Limited | Construction | 2025 |
| Power Gear Transmissions Limited | Wholesale & retail | 2022 |
| Powerforce Field Marketing and Retail Services Limited | Professional & scientific | 2007 |
| PQS2 Limited | Construction | 2015 |
| Prabha Consultancy Limited | Other services | 2017 |
| Pragmatic Estates Limited | Real estate | 2017 |
| Pranava Yoga Limited | Other services | 2022 |
| Pranitha Estates Limited | Real estate | 2022 |
| Prashika Limited | Information & communication | 2017 |
| Pratt's Pods Ltd. | Manufacturing | 2013 |
| Precious Promise Ltd | Transport & logistics | 2016 |
| Precise Fastenings & Supplies Limited | Wholesale & retail | 1987 |