| Plane Audits Limited | Administrative & support | 1996 |
| Plans for Building Ltd | Professional & scientific | 2024 |
| Platform Five PUB Company Ltd | Hospitality | 2019 |
| Platinum Tiger Limited | Real estate | 2022 |
| Playle Farms Holdings Limited | Financial services | 2019 |
| Playle Farms Limited | Professional & scientific | 1970 |
| Pledgdon Green Management Company Limited | Households | 2024 |
| PLS London (W1) Limited | Construction | 2022 |
| PLS London Limited | Construction | 2008 |
| Plumbers Ware Limited | Construction | 2014 |
| Plvs Ultra Ltd | Information & communication | 2024 |
| Plwmp Limited | Health & social care | 2021 |
| PMP (M & E) Contracts Limited | Construction | 2010 |
| Podia.Work Ltd | Information & communication | 2021 |
| Police Recovery Limited | Extraterritorial | 2004 |
| Ponsbourne Security Limited | Administrative & support | 2023 |
| Porch Properties Ltd | Real estate | 2021 |
| Porthleven Properties Limited | Professional & scientific | 1993 |
| Portobello Tents Limited | Hospitality | 2015 |
| Portofino Fine Foods LLP | | 2023 |
| Positive Edge Consulting Ltd | Other services | 2019 |
| Precision Pipes Plumbing and Heating Limited | Construction | 2024 |
| Pregame Industries Limited | Arts & recreation | 2025 |
| Premie Cars Limited | Transport & logistics | 2023 |
| Presdales School Academy Trust | Education | 2012 |
| Prestige Loft Company (Herts) Limited | Manufacturing | 2018 |
| Prestige Property Specialists Ltd | Construction | 2025 |
| Price Private Finance Limited | Financial services | 2012 |
| Pridmore COX Ltd | Professional & scientific | 2021 |
| Primal ARB Ltd | Wholesale & retail | 2023 |
| Primebuild Herts Ltd | Construction | 2025 |
| Principal Trees Limited | Other services | 2009 |
| Priority Cleaning Services Limited | Administrative & support | 2011 |
| Pro Mech London Limited | Construction | 2026 |
| Procurefm Limited | Professional & scientific | 2025 |
| Production Assist Ltd | Transport & logistics | 2020 |
| Professional Membership Ltd | Other services | 2026 |
| Profilens Limited | Real estate | 2025 |
| Property-Angels.(Gb) Ltd | Construction | 2014 |
| Prophop Limited | Real estate | 2024 |
| Prosales Group Ltd | Administrative & support | 2010 |
| Proserve Maintenance Limited | Construction | 2025 |
| Prospero Property Portfolio Limited | Real estate | 2014 |
| Prosurvey Ltd | Professional & scientific | 2024 |
| Protect & Prevent Ltd | Public administration | 2019 |
| Provenair Limited | | 1950 |
| Provoking Content Ltd | Professional & scientific | 2018 |
| Prudential Risk and Treasury Advisory Services Limited | Professional & scientific | 2017 |
| PSI Heating Ltd | Construction | 2017 |
| Puckeridge Local Store Ltd | Wholesale & retail | 2023 |
| Pullinger Enterprises Limited | Wholesale & retail | 2021 |
| Pullinger Landscapes Limited | Administrative & support | 2017 |
| Pulse Fitness Personal Trainers Ltd | Arts & recreation | 2014 |
| Pure Wealth Limited | Professional & scientific | 2015 |
| Purepropertiesco. Ltd | Real estate | 2025 |
| Purple MOO Ltd | Wholesale & retail | 2020 |
| PXP Solutions Limited | Information & communication | 1987 |
| Pyblox Limited | Information & communication | 2025 |
| Pyrexistech Ltd | Information & communication | 2025 |
| Q & a Law (UK) Ltd | Professional & scientific | 2010 |
| Q4ME Limited | Information & communication | 2021 |
| QI International Ltd | Professional & scientific | 2015 |
| Quaker Road Management Company Limited | Households | 1973 |
| Quality Signs Limited | Manufacturing | 2011 |
| Quantam B Ltd | Real estate | 2014 |
| Quince Hall Farm (Blackmore) Residents Management Company Limited | Households | 2023 |
| Qweenz Hair Therapy CIC | Other services | 2025 |
| R L B Equestrian Ltd | Arts & recreation | 2021 |
| R M & a Consulting Limited | Professional & scientific | 2008 |
| R MOY Builders Ltd | Construction | 2020 |
| R S Electrics (Herts) Limited | Construction | 2012 |
| R&C Hospitality Ltd | Hospitality | 2023 |
| R.& R.Crook Limited | Construction | 1960 |
| RAC003 Limited | Extraterritorial | 2018 |
| Rainbow Developments Limited | Construction | 2002 |
| RAJ Tandoori Ltd | Hospitality | 2023 |
| Ralph Sadleir School | Education | 2013 |
| Ranger Maintenance Ltd | Real estate | 2015 |
| Ranger Property Investments Limited | Real estate | 2021 |
| Rapid Roadside Rescue Ltd | Extraterritorial | 2013 |
| Rapier Design Limited | Professional & scientific | 1988 |
| Rapiergroup Limited | Financial services | 2017 |
| Rapiergroup Trustees Limited | Financial services | 2025 |
| Raven Armoury Limited | Extraterritorial | 1997 |
| RBJ Investments Limited | Financial services | 2021 |
| RCB Organics Ltd | Wholesale & retail | 2025 |
| RCS UK Professionals Ltd | Administrative & support | 2010 |
| RD Consultancy Limited Partnership | | 2020 |
| RDA Autism & Adhd Practice Ltd | Health & social care | 2024 |
| RDF Technical Services Ltd | Construction | 2023 |
| RE Cafe Limited | Hospitality | 2019 |
| Readability Limited | Manufacturing | 1992 |
| Ready Steady Learn Limited | Education | 2025 |
| Reality Link Ltd | Information & communication | 2022 |
| Reallate Software Ltd | Information & communication | 2025 |
| Realqk Limited | Education | 2007 |
| Rebel Way Ltd | Wholesale & retail | 2021 |
| Recognise Design Limited | Information & communication | 2013 |
| Recognise Holding Ltd | Real estate | 2018 |
| Red Elvis Limited | Other services | 2016 |