| Papadee Estates Ltd | Real estate | 2021 |
| Papadee Family Estates LLP | | 2021 |
| Paperknife Productions Ltd | Information & communication | 2002 |
| Pardus Midgard Ltd | Construction | 2019 |
| Pasana Properties Ltd | Real estate | 2016 |
| PAT Jones & Associates Limited | Professional & scientific | 2000 |
| Patek Philippe UK Limited | Wholesale & retail | 1946 |
| Paul Pavli Consultancy Ltd | Professional & scientific | 2019 |
| Pawbloomcraft Ltd | Wholesale & retail | 2025 |
| Pawdriftdesigns Ltd | Wholesale & retail | 2025 |
| Pawglowdecor Ltd | Wholesale & retail | 2025 |
| Paynes Metal Recycling Limited | Water & waste | 2005 |
| PB Planning Consultancy Limited | Professional & scientific | 2015 |
| Peak Property Services Limited | Construction | 2002 |
| Pegmill Limited | Households | 1990 |
| People Potential and Performance Limited | Professional & scientific | 2000 |
| Perfect Pipework Limited | Administrative & support | 1990 |
| Perfect Sky Properties Limited | Real estate | 2006 |
| Peter Bennett (Structural Engineer) Limited | Administrative & support | 2002 |
| Peter Darvill Associates Limited | Arts & recreation | 1971 |
| Peterley Manor Farm Limited | Agriculture & fishing | 2022 |
| Petgleamcraft Ltd | Wholesale & retail | 2025 |
| Petits Choux Limited | Other services | 2008 |
| Pettideornaments Ltd | Wholesale & retail | 2025 |
| Piarco Developments Limited | Professional & scientific | 2005 |
| Piddington Properties Limited | Real estate | 2001 |
| Pineleigh Consultants Limited | Professional & scientific | 1998 |
| Pinpoint Marketing (UK) Limited | Administrative & support | 1997 |
| Pipers Corner School | Education | 1952 |
| Plainlyops Limited | Professional & scientific | 2025 |
| Planet Afryca Limited | Information & communication | 1999 |
| Platinum Autos Limited | Wholesale & retail | 2003 |
| Post Production Consultants Limited | Information & communication | 1992 |
| Potentially U Limited | Professional & scientific | 2004 |
| Practicality Brown Limited | Agriculture & fishing | 1987 |
| Pragmatic Marketing Limited | Wholesale & retail | 2003 |
| Pragmatic Maxim Limited | Information & communication | 2011 |
| Pratham Technologies UK Ltd | Manufacturing | 2024 |
| Preceestitches Ltd | Manufacturing | 2025 |
| Prescott Hamilton Limited | Wholesale & retail | 1997 |
| Press-Up Limited | | 1984 |
| Prestige Communication Services Limited | Information & communication | 1989 |
| Pride of Burnham Ltd | Hospitality | 2020 |
| Priests Limited | Wholesale & retail | 1995 |
| Primeho Ltd | Information & communication | 2022 |
| Printing & Graphic Machinery Limited | Wholesale & retail | 2002 |
| Proficio Services Limited | Health & social care | 2006 |
| Projad Bridge Ltd | Financial services | 2022 |
| Project-A Technology Limited | Information & communication | 2002 |
| Property & Investment Management Limited | Real estate | 1994 |
| Proud Construction Limited | Construction | 2003 |
| PTP Cyber Limited | Information & communication | 2024 |
| Purrdriftart Ltd | Wholesale & retail | 2025 |
| Purrflareco Ltd | Wholesale & retail | 2025 |
| Purrflarejewels Ltd | Wholesale & retail | 2025 |
| Purrwispart Ltd | Wholesale & retail | 2025 |
| Pylbrook Holdco Limited | Financial services | 2025 |
| Pyramid Forestry & Landscaping Limited | Agriculture & fishing | 2002 |
| Q8 Limited | Extraterritorial | 1998 |
| Quantummind Consulting and Services Ltd | Information & communication | 2023 |
| Queens Park Arts Centre Limited | Arts & recreation | 2001 |
| Quentin Cooper Limited | Information & communication | 2001 |
| Quickfold Business Solutions Limited | Manufacturing | 1992 |
| Quinton Consultants Limited | Professional & scientific | 1994 |
| R & S Plumbing & Heating Limited | Construction | 2005 |
| R&D Care Ltd | Health & social care | 2023 |
| R&M Lighting Limited | Professional & scientific | 2004 |
| Rainbow Silks Limited | Wholesale & retail | 1995 |
| Rajasthan Spice London Ltd | Hospitality | 2019 |
| Rajat Technologies Limited | Information & communication | 2007 |
| Rajkim Resources Limited | Hospitality | 1998 |
| RAK Rectory Hill Limited | Construction | 2021 |
| Randhawa Transport Limited | Transport & logistics | 2012 |
| Rapidscreed-Site Limited | Construction | 2014 |
| Rare Design Limited | Arts & recreation | 2006 |
| Ravineglow Handmade Ltd | Wholesale & retail | 2025 |
| RD Fabrications & Engineering Limited | Manufacturing | 2005 |
| Real Finance Partners LP | | 2004 |
| Rebellion Cider Company Limited | Hospitality | 2003 |
| Red Kite Business Systems Limited | Information & communication | 2003 |
| Red Tuna Technology Limited | Information & communication | 2004 |
| Redfearn Austin Interiors Limited | Professional & scientific | 1968 |
| Reefwisplamps Ltd | Wholesale & retail | 2025 |
| Reflex Tools Limited | Manufacturing | 1975 |
| Reggae Roaster Caribbean Takeaway Limited | Hospitality | 2023 |
| Regional Parking Services Ltd | Professional & scientific | 2004 |
| Regys Consultants (UK) Limited | Professional & scientific | 1998 |
| Resale Solutions LLP | | 2018 |
| Resinex UK Ltd | Wholesale & retail | 1985 |
| Retrotape Limited | Manufacturing | 2002 |
| Revolution Cycles Limited | Manufacturing | 2003 |
| REX Investments Limited | Real estate | 1936 |
| Ribocon Commercial Limited | Wholesale & retail | 1989 |
| Ribocon Retirement Homes Limited | Wholesale & retail | 1987 |
| Ridgeways (FP) Limited | Administrative & support | 2007 |
| Rightzone Accountants Ltd | Professional & scientific | 2007 |
| Riverside Business Centre Limited | Real estate | 1990 |
| RMG Contractors Limited | Construction | 2007 |
| Robin Elliott Limited | Construction | 1997 |
| Roblec Properties (Barnet) Limited | Extraterritorial | 1993 |