| Primeshift Staffing Limited | Administrative & support | 2025 |
| Primetone Builders Limited | Other services | 1991 |
| Primrose Clinic Ltd | Health & social care | 2011 |
| Primrose SE Holdings Limited | Financial services | 2020 |
| Primrose Tech Ltd | Wholesale & retail | 2020 |
| Primula Developments Limited | Construction | 2016 |
| Primus Nursing Limited | Administrative & support | 2015 |
| Prince's Certifications Ltd | Professional & scientific | 2023 |
| Prince's Consultancy Services Limited | Professional & scientific | 2003 |
| Prince's Properties Ltd | Real estate | 2018 |
| Principal Advisory Alliance Limited | Professional & scientific | 2015 |
| Principle Physiotherapy Ltd | Other services | 2019 |
| Print Acumen Limited | Manufacturing | 2016 |
| Print Impressions Digital Limited | Professional & scientific | 2008 |
| Printaid (UK) Limited | Professional & scientific | 2005 |
| Printech Circuit Laboratories Limited | Manufacturing | 1980 |
| Printed Future Ltd. | Manufacturing | 2017 |
| Printee Ltd | Wholesale & retail | 2023 |
| Printworld (Harlow) LLP | | 2003 |
| Priors Field Management Limited | Households | 2005 |
| Priory Hall Halstead Limited | Real estate | 2004 |
| Priory Innovations Ltd | Extraterritorial | 2023 |
| Priory Mews (Hornchurch) Management Company Limited | Households | 1997 |
| Prism Architecture Limited | Professional & scientific | 2023 |
| Prison Consultants Ltd | Professional & scientific | 2013 |
| Pristine Exteriors Essex Ltd | Administrative & support | 2026 |
| Private GP Partnership Limited | Health & social care | 2023 |
| Private Parking Management Limited | Transport & logistics | 2016 |
| Priver & Bern Ltd | Construction | 2018 |
| Priya Education Limited | Education | 2025 |
| Pro 53 Ltd. | Arts & recreation | 2015 |
| Pro AD Media Ltd | Information & communication | 2014 |
| Pro Cinema Rooms Ltd | Administrative & support | 2026 |
| Pro House Restore Ltd | Construction | 2021 |
| Pro Learning Alliance Ltd | Education | 2013 |
| Pro Nutrition Clinic Ltd | Other services | 2013 |
| Pro-Actions Business Coaching and Support Ltd | Professional & scientific | 2015 |
| Pro-Actions Business Improvement (Essex) Ltd | Professional & scientific | 2011 |
| Pro-Fit Kitchen Installations Limited | Construction | 2017 |
| Pro-Van Ltd | Wholesale & retail | 2021 |
| Proattiva Limited | Professional & scientific | 2015 |
| Problem-Hunting Ltd | Professional & scientific | 2022 |
| Process Cooling Consultancy Limited | Wholesale & retail | 2022 |
| Procrate UK Ltd | Wholesale & retail | 2025 |
| Proexpert Accountants Ltd | Professional & scientific | 2023 |
| Professional Assistance Group Ltd | Professional & scientific | 2021 |
| Professor Darryl Newport Limited | Other services | 2021 |
| Proficio Accountants Limited | Professional & scientific | 2015 |
| Progen Developments Ltd | Construction | 2014 |
| Progressive Strategy Solutions Ltd | Professional & scientific | 2018 |
| Project 10 Developments Limited | Real estate | 2025 |
| Project 2 Services Ltd | Construction | 2022 |
| Project 275 Limited | Manufacturing | 2018 |
| Project 3 Services Ltd | Professional & scientific | 2024 |
| Project 400 Limited | Manufacturing | 2012 |
| Project Advisory Services Ltd | Professional & scientific | 2025 |
| Project Holdings JCA Ltd | Real estate | 2022 |
| Project J.D Consultancy Ltd | Water & waste | 2023 |
| Project JCA Group Ltd | Financial services | 2024 |
| Project Lead Ltd | Professional & scientific | 2024 |
| Project Livelong Limited | Health & social care | 2017 |
| Project Mind Empower CIC | Health & social care | 2020 |
| Project Octane Ltd | Wholesale & retail | 2025 |
| Project Surveying Services Ltd | Professional & scientific | 2019 |
| Project Unicorn Limited | Wholesale & retail | 2025 |
| Projex Support Ltd | Administrative & support | 2021 |
| Promedical Clinical Services Limited | Health & social care | 2025 |
| Promedical Personnel Limited | Administrative & support | 2007 |
| Promena Consulting Ltd | Information & communication | 2016 |
| Prometheus Advisory Ltd | Administrative & support | 2019 |
| Prometheus Operations Limited | Administrative & support | 2026 |
| Prominent Accountants and Advisory Ltd | Professional & scientific | 2022 |
| Promote Ltd | Information & communication | 2025 |
| Prompt Pictures Limited | Information & communication | 2026 |
| Promzy Cleaning Services Ltd | Administrative & support | 2026 |
| Propel Construction Management Ltd | Professional & scientific | 2016 |
| Proper Trading Ltd | Manufacturing | 2023 |
| Properties 48 Limited | Real estate | 2016 |
| Properties Comfort Limited | Real estate | 2024 |
| Property 24 Maintenance Ltd | Construction | 2018 |
| Property Absolute Ltd | Professional & scientific | 2022 |
| Property Focus Real Estate Ltd | Real estate | 2010 |
| Property Investment Collaboration Limited | Real estate | 2020 |
| Property Investments (Romford) Limited | Real estate | 1958 |
| Property Land Consultants Limited | Real estate | 2024 |
| Property Maintenance and Repair Team Ltd | Professional & scientific | 2018 |
| Property NO.22 Limited | Real estate | 2022 |
| Property Solutions Pro Ltd | Real estate | 2024 |
| Property Sphere Development Limited | Construction | 2020 |
| Property Stop Estate Management Limited | Real estate | 2020 |
| Property Stop Limited | Real estate | 1996 |
| Propertyshot Services Limited | Construction | 2021 |
| Properyforge Ltd | Administrative & support | 2024 |
| Propilicious Limited | Professional & scientific | 2016 |
| Propsys Services Ltd | Construction | 2019 |
| Proptek Ltd | Information & communication | 2010 |
| Propulse Property Consultancy Limited | Construction | 2020 |
| Proserve Management Ltd | Professional & scientific | 2024 |
| Prospect Business Solutions Limited | Other services | 2006 |
| Prospective Property Ltd | Real estate | 2019 |