| Polydrax Ltd | Information & communication | 2026 |
| Ponari Limited | Hospitality | 2011 |
| Pondstone Investments Limited | Real estate | 1961 |
| Ponnan Limited | Professional & scientific | 2018 |
| Pools and Leisure Services Ltd | Construction | 2021 |
| POP Events Limited | Arts & recreation | 2015 |
| POP Goes My Heart Ltd | Arts & recreation | 2022 |
| Poptani Financial Solutions Limited | Other services | 2004 |
| Porges Mechanical Electrical Limited | Construction | 2017 |
| Port Flight Limited | Construction | 2022 |
| Port Royal Pirate Experience Ltd | Education | 2020 |
| Portwood Properties Limited | Households | 1992 |
| Poters Bar Market Ltd | Wholesale & retail | 2026 |
| Potok Digital Group Ltd | Information & communication | 2022 |
| Potters Bar Bowls Club (2000) Limited | Arts & recreation | 2000 |
| Potters Bar Limited | Hospitality | 2017 |
| Potters Bar Lofts & Extensions Ltd | Construction | 2017 |
| Potters Bar Town Arena Ltd | Education | 2024 |
| Potters Bar Town Football Club Ltd | Arts & recreation | 2021 |
| Potters Bar United Football Club Limited | Education | 2022 |
| Potters Bar Windows Ltd | Construction | 2014 |
| Potters Food Ltd | Hospitality | 2024 |
| Potters Kebab Ltd | Hospitality | 2013 |
| Pound 1971 Ltd | Wholesale & retail | 2021 |
| Power Health and Fitness Ltd | Arts & recreation | 2010 |
| Power Snack Ltd | Manufacturing | 2018 |
| PPM Commercial Services Ltd | Construction | 2025 |
| Praeficere Certos Ltd | Wholesale & retail | 2024 |
| Praise & Glory Ltd | Wholesale & retail | 2024 |
| Pratima Ltd | Information & communication | 2024 |
| Praxis Dj-Live Limited | Administrative & support | 2023 |
| Praxis Entertainment Ltd | Professional & scientific | 2016 |
| Praxis Records Limited | Information & communication | 2022 |
| Praxxes Limited | Professional & scientific | 2008 |
| Prelude Alarm Co. Limited | Professional & scientific | 1998 |
| Premier Clean Cleaning Limited | Administrative & support | 2022 |
| Premier Deals Global UK Ltd | Wholesale & retail | 2024 |
| Premier Eco Cards Ltd | Manufacturing | 2020 |
| Premier Ship Models Limited | Manufacturing | 2001 |
| Premier Transport Services Limited | Transport & logistics | 2020 |
| Premio Group Properties Ltd | Real estate | 2022 |
| Premit Ltd | Real estate | 2024 |
| Premium Maintenance Ltd | Other services | 2017 |
| Premium Transport Solutions Limited | Transport & logistics | 2020 |
| Prenouf Ltd | Real estate | 2021 |
| Prepbox Nutrition Ltd | Administrative & support | 2017 |
| Presentation & Binding Supplies Limited | Manufacturing | 1985 |
| Prestige Arts (London) Ltd | Wholesale & retail | 2015 |
| Pretty Cool Customers Limited | Construction | 2014 |
| Prettyfly Lemi Limited | Real estate | 2014 |
| Pridi Properties Limited | Real estate | 2016 |
| Prime Jobs Recruitment Ltd | Administrative & support | 2025 |
| Prime Point Construction Ltd | Construction | 2025 |
| Prime Time Properties UK Group Ltd | Real estate | 2023 |
| Primeflair Management Limited | Real estate | 1995 |
| Primelectrics Limited | Construction | 2018 |
| Primestay Property Management Limited | Real estate | 2026 |
| Primro & Co Limited | Real estate | 2024 |
| Princigo Ltd | Manufacturing | 2019 |
| Priory GAS Commercial Heating Ltd | Manufacturing | 2026 |
| Priory Property Maintenance Limited | Construction | 2005 |
| Priory Residential Ltd | Real estate | 2019 |
| Private Client Facilities Ltd | Financial services | 2008 |
| Pro Enviro Services Limited | Administrative & support | 2007 |
| Pro Excellence Partnership Ltd | Professional & scientific | 2024 |
| Pro Inclusion Ltd | Education | 2026 |
| Pro IT Outsourcing Ltd | Information & communication | 2023 |
| Pro-Elite Soccer Ltd | Administrative & support | 2014 |
| Pro-Info Consulting UK Ltd | Information & communication | 2010 |
| Proactive Plumbing & Maintenance Ltd | Construction | 2026 |
| Prodigy Estates Limited | Real estate | 2008 |
| Prodigy Waves Ltd | Administrative & support | 2014 |
| Professional Medicine Limited | Health & social care | 2010 |
| Professional VAT Consultants Limited | Professional & scientific | 2009 |
| Profire Services Limited | Administrative & support | 2014 |
| Project IT (London) Ltd | Administrative & support | 2016 |
| Prologic UK Limited | Information & communication | 2009 |
| Promedical Care Services Limited | Professional & scientific | 2025 |
| Promenade Studios Ltd | Information & communication | 2016 |
| Prometheus Care Solutions Ltd | Health & social care | 2025 |
| Prominent Facilities Limited | Construction | 2019 |
| Prontostat Limited | Wholesale & retail | 1995 |
| Propertiesduo Limited | Real estate | 2022 |
| Property and Building Repairs Limited | Construction | 2024 |
| Property Force Limited | Real estate | 1997 |
| Property Global Management Limited | Real estate | 2005 |
| Property Liaisons (Developments) Limited | Construction | 2001 |
| Property Management Estates Ltd | Real estate | 2012 |
| Proppertunity Limited | Real estate | 2007 |
| Proptark 2 Limited | Real estate | 2020 |
| Proptark Limited | Information & communication | 2020 |
| Prosperity Independent Ltd | Real estate | 2004 |
| Protech Clean Solutions Limited | Administrative & support | 2013 |
| Protech Garden Solutions Limited | Administrative & support | 2013 |
| Protech Intruder Solutions Limited | Administrative & support | 2013 |
| Protech Pest Solutions Limited | Other services | 2013 |
| Protech Property Solutions Limited | Construction | 2009 |
| Protech Waste Solutions Limited | Administrative & support | 2013 |
| Proteus Equity Holdings Ltd | Financial services | 2016 |
| Protiuc Construction Ltd | Construction | 2022 |