| POD Management LLP | | 2025 |
| Polaris Finance Limited | Financial services | 2007 |
| Polor Wise Ltd | Other services | 2022 |
| Porter Estates Limited | Real estate | 2001 |
| Pose & Repeat Ltd | Professional & scientific | 2020 |
| Postech Till Systems Limited | Wholesale & retail | 2010 |
| Potato Print Limited | Manufacturing | 2001 |
| Poynders END Limited | Financial services | 2007 |
| Pragmedic Limited | Professional & scientific | 1998 |
| Precious Cuts Limited | Other services | 2007 |
| Precision Dental Products Limited | Extraterritorial | 2007 |
| Premier Choice Financial Services Limited | Financial services | 2000 |
| Premier Elite Management Limited | Real estate | 1996 |
| Premier Garage (Southgate) Limited | Real estate | 1947 |
| Premier VCT (Mailbox) Limited | Hospitality | 1999 |
| Premium Chauffeurs Ltd | Transport & logistics | 2026 |
| Premium Surgical Brands Limited | Wholesale & retail | 2008 |
| Prestige Performance Limited | Wholesale & retail | 1996 |
| Pricesave Limited | Extraterritorial | 1989 |
| Pride Vehicle Contracts (G.B.) Limited | Professional & scientific | 1997 |
| Priestnall Consultancy Limited | Professional & scientific | 2014 |
| Primepass Global Ltd | Professional & scientific | 2023 |
| Primus Build Limited | Construction | 2007 |
| Prinish Properties Ltd | Real estate | 2017 |
| Priority Heating Limited | Construction | 2003 |
| Priory Consulting Services Ltd | Professional & scientific | 2004 |
| Priory PUB Company Limited | Real estate | 1999 |
| Private Power Limited | Manufacturing | 2004 |
| Process Logistics Ltd | Administrative & support | 2003 |
| Produce UK Limited | Arts & recreation | 2002 |
| Programme Office Limited | Information & communication | 1985 |
| Progressive Consulting Ltd | Information & communication | 2001 |
| Project Forma Ltd | Professional & scientific | 2025 |
| Projectwide Ltd | Professional & scientific | 1997 |
| Properties Upgrade Limited | Real estate | 2022 |
| Property DOC Ltd | Real estate | 2021 |
| Property File ( Hertford ) Ltd | Real estate | 2003 |
| Prospect Court Management Company (ST. Albans) Limited | Professional & scientific | 1986 |
| Prosperity Property Management Services Limited | Real estate | 2020 |
| Protection Dogs London Limited | Administrative & support | 2020 |
| Prototype Projects Limited | Manufacturing | 2000 |
| Prototype Solutions Limited | Manufacturing | 2000 |
| Prowriters Limited | Information & communication | 1972 |
| PSD Group Holdings Limited | Financial services | 2023 |
| PSP Accounting Limited | Professional & scientific | 2004 |
| PSW Accounting Services Limited | Professional & scientific | 2003 |
| PT Driveways & Landscaping Ltd | Administrative & support | 2023 |
| Pubdam Limited | Arts & recreation | 1997 |
| Public Paradigm Ltd | Professional & scientific | 2015 |
| Punni Pharmacy Limited | Wholesale & retail | 2002 |
| Puralog Ltd | Information & communication | 2012 |
| Purfleet Flooring Limited | Construction | 2008 |
| Purple Procurement International Limited | Administrative & support | 2007 |
| PWM UK Limited | Administrative & support | 2006 |
| Pyrmont Build Limited | Construction | 2006 |
| Qamca Care CIC | Health & social care | 2024 |
| Qik-Link Limited | Other services | 2017 |
| Quality Paving & Driveways Limited | Construction | 2007 |
| Quality Pizza and Pasta Limited | Hospitality | 2003 |
| Quanticate International Limited | Health & social care | 1996 |
| Quanticate UK Limited | Professional & scientific | 1997 |
| Quantum Financial Advisers Ltd | Financial services | 2011 |
| Quantum KPO Ltd | Professional & scientific | 2023 |
| Quantum Recruitment Services Ltd | Professional & scientific | 2019 |
| Quantum UK Business Solutions Limited | Professional & scientific | 2016 |
| Quantum Wills and Estate Planning Ltd | Professional & scientific | 2018 |
| Quartz Technology Ltd | Manufacturing | 1996 |
| Queniborough Lodge Management Company Limited | Households | 2026 |
| R & F Pallets Limited | Administrative & support | 2002 |
| R a Webster (Associates) Limited | Information & communication | 2004 |
| R G Parrott Limited | Construction | 2000 |
| R H Air Conditioning Limited | Construction | 2007 |
| R T Properties Limited | Real estate | 2003 |
| R. Brading Limited | Construction | 2005 |
| R. G. C. Corporate Services Ltd | Administrative & support | 2002 |
| R. I. Executive Chauffeurs Limited | Transport & logistics | 2001 |
| R.A.G. Associates Limited | Professional & scientific | 2006 |
| R.D. Travel Services Limited | Administrative & support | 1980 |
| R.Harkness & Co. Limited | Agriculture & fishing | 1954 |
| R.K. Language Services Ltd | Other services | 2007 |
| R.V.R. Services Ltd | Administrative & support | 2003 |
| R.W.Luckins(Stamford)Limited | Professional & scientific | 1970 |
| Rabbit Computers Limited | Information & communication | 1992 |
| Racksafe Solutions Limited | Administrative & support | 2003 |
| Radiant Light | Information & communication | 1999 |
| Radlett Barber Company Limited | Other services | 2002 |
| Radworthy Limited | Real estate | 2002 |
| Railtek Limited | Construction | 1997 |
| Rainbow Day Nursery EOT Ltd | Professional & scientific | 2025 |
| Rainbow DRY Cleaners (Knebworth) Limited | Administrative & support | 2003 |
| Raine and Co (UK) Limited | Real estate | 1996 |
| Raine and Co. (Hatfield) Limited | Real estate | 2005 |
| Raine and Co. (Potters Bar) Ltd | Real estate | 1992 |
| Raine and Co. Management Limited | Professional & scientific | 2009 |
| RAJ Vogue Cheshunt Ltd | Hospitality | 2017 |
| Ramar Limited | Manufacturing | 1994 |
| Rands Print Motor Specialists Limited | Manufacturing | 1997 |
| Rapidco Ltd | Health & social care | 2002 |
| Ravenhart Services (DAG) Limited | Administrative & support | 2007 |
| Ravidassia Community Centre | Other services | 2006 |