| Panoptic Plumbing Limited | Construction | 2022 |
| Panshanger Hardware Limited | Wholesale & retail | 1978 |
| Panshanger Properties Limited | Real estate | 2022 |
| Parah Properties Limited | Real estate | 2026 |
| Parcs Utilities Ltd | Construction | 2020 |
| Paridyn Limited | Information & communication | 2004 |
| Paridyn Properties Limited | Real estate | 2012 |
| Parj Holdings Ltd | Real estate | 2025 |
| Park Royal Ltd | Education | 1999 |
| Parker Capital Holdings Ltd | Real estate | 2025 |
| Parkmatic (UK) Limited | Professional & scientific | 2024 |
| Parkvale Financial Services Limited | Professional & scientific | 2024 |
| Parkway Gardens Apartments Management Company Limited | Administrative & support | 1992 |
| Parmenter Properties Ltd | Real estate | 2024 |
| Parmenter Spaces Limited | Real estate | 2025 |
| Partrad Limited | Wholesale & retail | 2022 |
| Pascual Beká Architecture Ltd | Professional & scientific | 2021 |
| Pathology Performance Plus Limited | Health & social care | 2016 |
| Patient-Centred Outcomes Ltd | Professional & scientific | 2023 |
| Patrick PAT Ltd | Transport & logistics | 2022 |
| Paul Buchanan Evolution Design Ltd | Professional & scientific | 2017 |
| Paul Clews Painters and Decorators Ltd | Construction | 2019 |
| Paul Hutchison Ltd | Construction | 2020 |
| Paul Noble Roofing Limited | Construction | 2012 |
| PAW Ventures Ltd | Wholesale & retail | 2026 |
| Paycargo UK Limited | Transport & logistics | 2022 |
| Paypoint Collections Limited | Administrative & support | 1998 |
| Paypoint Network Limited | Administrative & support | 1994 |
| Paypoint Payment Services Limited | Administrative & support | 2013 |
| Paypoint PLC | Information & communication | 1998 |
| Paypoint Trust Managers Limited | Other services | 1997 |
| Payroll & Contracting Management Limited | Professional & scientific | 2009 |
| PC Innovation Limited | Wholesale & retail | 2025 |
| PC Repairs Welwyn Limited | Information & communication | 2019 |
| Pearce & Co Accountancy Ltd | Professional & scientific | 2024 |
| Peartree Clinic Holdings Limited | Financial services | 2024 |
| Peartree Clinic Welwyn Limited | Health & social care | 2023 |
| Pedal Lounge Ltd | Manufacturing | 2026 |
| Pegasus Travel Ltd | Transport & logistics | 2015 |
| Pelican Place Nursery Limited | Education | 2005 |
| Pelix Consulting Ltd. | Professional & scientific | 2021 |
| Pennies Investments Ltd | Real estate | 2026 |
| Penny Auction UK Limited | Wholesale & retail | 2019 |
| Penrose & Penrose Ltd | Information & communication | 2023 |
| Penryn Bridge Limited | Real estate | 2003 |
| Penryn Bridge Management Limited | Real estate | 2007 |
| Pentacle Electrical and Security Ltd | Construction | 2024 |
| Pentley Limited | Other services | 2005 |
| People Platforms Consulting Limited | Administrative & support | 2025 |
| Perfect Moment - Flowers Limited | Wholesale & retail | 2005 |
| Permobil Limited | Wholesale & retail | 2001 |
| Perrott Property Investments Ltd | Real estate | 2015 |
| Petermary Limited | Information & communication | 2023 |
| PG Maintenance & Exports Ltd | Construction | 2026 |
| PGE Olivier Limited | Real estate | 2019 |
| Phoenix Total Security Limited | Construction | 1996 |
| Phoenixhuma Ltd | Wholesale & retail | 2024 |
| Physiogenics Ltd | Other services | 2024 |
| Phyzioplus Limited | Health & social care | 2014 |
| Picasso CUT & Coffee Ltd | Other services | 2020 |
| Picklella Ltd | Wholesale & retail | 2024 |
| Picture and Motion Ltd | Professional & scientific | 2013 |
| Pinecones Day Nursery Limited | Health & social care | 2017 |
| Pinkie Studio Ltd | Wholesale & retail | 2024 |
| Pinnacle Software Solutions Ltd | Information & communication | 2026 |
| Pinnacle T Ltd | Hospitality | 2022 |
| Pioneering Plumbing Ltd | Construction | 2019 |
| Pipestar Plumbing Ltd | Construction | 2024 |
| Piramed Limited | Professional & scientific | 2001 |
| Piskey LED Limited | Manufacturing | 1940 |
| Pit-Stop Auto Centre (WGC) Limited | Wholesale & retail | 2005 |
| Pixelvirt Technology Ltd | Information & communication | 2025 |
| Pkco Limited | Professional & scientific | 2020 |
| Platinum Scaffolding Limited | Construction | 2003 |
| Plaudit Ltd | Information & communication | 2026 |
| Play Away Day Nurseries Limited | Education | 1993 |
| Player Capital Consulting Ltd | Administrative & support | 2010 |
| Plencner UK Ltd | Construction | 2017 |
| PLM Holdings Limited | Financial services | 2017 |
| Plowright Hinton Limited | Professional & scientific | 1991 |
| Plutosjt Limited | Wholesale & retail | 2025 |
| Pnja Consultancy Ltd | Information & communication | 2023 |
| Poem Photography Ltd | Professional & scientific | 2025 |
| Poku Solutions Ltd | Information & communication | 2013 |
| Polaris Centre Management Company Limited | Real estate | 2007 |
| Polaris Wilderness Adventure Limited | Arts & recreation | 2012 |
| Poleshift Limited | Wholesale & retail | 1988 |
| Policy and Secretariat Services Ltd | Professional & scientific | 2017 |
| Policy to Practice Limited | Professional & scientific | 2022 |
| Poodmark Eyzi Software Limited | Wholesale & retail | 2024 |
| Poplar Care Agency Ltd. | Health & social care | 2018 |
| Poppies Day Nurseries Limited | Health & social care | 2009 |
| POS Property Limited | Real estate | 2013 |
| Power in Clarity Limited | Administrative & support | 2021 |
| PPC Accountants UK Limited | Professional & scientific | 2026 |
| Pradav Infrastructure Limited | Real estate | 2025 |
| Pram Fresh Ltd | Administrative & support | 2022 |
| Praxis Consult Ltd | Professional & scientific | 2024 |
| Precast Concrete UK Limited | Construction | 2013 |
| Precision Clinical Wellbeing Ltd | Health & social care | 2026 |