| PCD Home Inspectors LLP | | 2006 |
| Pennwood Connect Ltd | Administrative & support | 2024 |
| Pennwood Travel Solutions Ltd | Administrative & support | 2024 |
| Phoenix House Holdings Limited | Professional & scientific | 1986 |
| Pipe Dreams of Kensington Limited | Transport & logistics | 1990 |
| Polypax Limited | | 1984 |
| Port Nicholson Ltd | Construction | 2002 |
| Possibility Enterprises Ltd | Administrative & support | 2006 |
| Powderspray Limited | Professional & scientific | 1969 |
| PPS Builders Limited | | 1988 |
| Preflame Limited | | 1981 |
| Princeptive Consulting Limited | Information & communication | 2006 |
| Principal Office Systems Limited | | 1984 |
| Printing and Graphic Machinery Installations Limited | Manufacturing | 1980 |
| Propertysan Limited | Professional & scientific | 2024 |
| Pullins Surveyors Limited | Professional & scientific | 2006 |
| Pure Cold Group Limited | Manufacturing | 2024 |
| Quantum Computer Systems Limited | | 1981 |
| Quatrro Holdings Ltd | Real estate | 2023 |
| R & a Farms | Agriculture & fishing | 1992 |
| R J Services Limited | Professional & scientific | 2003 |
| R J Turner Associates Limited | Professional & scientific | 2007 |
| R Jameson Limited | Transport & logistics | 2005 |
| R.T. Machinery Limited | Administrative & support | 2003 |
| R1 Print and Design Ltd | Manufacturing | 2004 |
| R2CONTRACTS Limited | Construction | 2003 |
| R8911 Properties Ltd | Real estate | 2014 |
| RAJ & Sons Investments Ltd | Real estate | 2016 |
| Rapture Club Ltd | Administrative & support | 2019 |
| RCM Louvres Limited | Manufacturing | 2007 |
| Real Aquatics Limited | Wholesale & retail | 2015 |
| Redfield Educational Foundation | Education | 1990 |
| Redhudson Limited | | 1980 |
| Relish Kitchens Limited | Wholesale & retail | 2006 |
| Risby Air Conditioning Co. Limited | Energy | 1971 |
| Rocket Associates UK Limited | Professional & scientific | 2003 |
| Rockwells(Office Equipment)Limited | | 1944 |
| Rogco Limited | Extraterritorial | 2006 |
| Rosehill Instruments Limited | Wholesale & retail | 1977 |
| Roseneath Properties Ltd | Construction | 2004 |
| Rosetta Capital IV GP Limited | Financial services | 2012 |
| Rosetta Capital Limited | Financial services | 2000 |
| Rosetta Capital V GP Limited | Financial services | 2013 |
| Rosetta Capital VI, LP | | 2021 |
| RPB Consulting Limited | Real estate | 2005 |
| Ruskin Projects Limited | | 1985 |
| S J Endean & SON LLP | | 2006 |
| Saddle Safari Limited | Wholesale & retail | 2003 |
| Safety Associated Frame Engineering Limited | | 1983 |
| Sajan Stores Limited | Wholesale & retail | 2007 |
| SAN Martin Properties Limited | Other services | 2006 |
| Satellite Antenna Systems Limited | | 1985 |
| Scin Matters Ltd | Health & social care | 2022 |
| Securepack Express Ltd | Transport & logistics | 2025 |
| Securon (Amersham) Limited | Manufacturing | 1947 |
| Securon Limited | Extraterritorial | 1955 |
| Seer Green Accountancy Limited | Professional & scientific | 2006 |
| SEK Maintenance Limited | Other services | 2007 |
| Sellair | | 1985 |
| Shotohouse Ltd | Real estate | 2021 |
| Sign-Rite Grafix Limited | Extraterritorial | 2013 |
| Silver Pebble Ltd | Professional & scientific | 2006 |
| Skjjb Limited | Real estate | 2005 |
| Slavehill Marketing Limited | Information & communication | 2005 |
| Solutions in Motion Limited | Information & communication | 2002 |
| Somnium Financial Planning Ltd | Administrative & support | 2016 |
| Southern Transport Limited | | 1982 |
| Spark Joy Limited | Wholesale & retail | 2020 |
| Spin Doctor Limited | Professional & scientific | 2004 |
| Spirit YPC Limited | Arts & recreation | 2013 |
| Sprods Limited | Information & communication | 2008 |
| ST. Andrews Bookshop Limited | Wholesale & retail | 1977 |
| Stacote Securities Limited | | 1972 |
| Storm Site Surveys Ltd | Construction | 2006 |
| Stryve Sport Limited | Information & communication | 2023 |
| Swiftquest Associates Limited | Information & communication | 2013 |
| TDT Electronics Limited | Manufacturing | 1980 |
| Technovisual Ltd | Administrative & support | 2004 |
| Teikyo Services (U.K.) Limited | Hospitality | 1988 |
| Terrapin Building and Civil Engineering Limited | Professional & scientific | 1971 |
| Thames Valley Pet Food Supplies Limited | Wholesale & retail | 1968 |
| THE Bluebell Letting Shop Ltd | Real estate | 2002 |
| THE Chiltern Lift Company Limited | Manufacturing | 1973 |
| THE IT GUY Limited | Information & communication | 2003 |
| THE Kitchen Fitting Company Limited | Construction | 1996 |
| THE Magpies Music Ltd | Arts & recreation | 2020 |
| THE Therapy Centre (Bedford) Ltd | Health & social care | 2002 |
| Tierel Limited | Administrative & support | 2000 |
| Tiny Olives Limited | Information & communication | 2025 |
| Tope OJO Memorial Welfare Organisation Ltd | Health & social care | 2004 |
| TPW Print | | 1996 |
| Training to Protect Ltd | Public administration | 2026 |
| Trilogy Aviation Solutions Ltd | Financial services | 2006 |
| Trilogy Business Solutions Ltd | Financial services | 2006 |
| Tuckin (Caterers) Limited | Hospitality | 1977 |
| Turners Court Youth Trust | Health & social care | 1909 |
| Turnkey Business Systems (Marlow) Limited | | 1985 |
| UK Sports Performance Ltd | Wholesale & retail | 2013 |
| Vale Lettings Limited | Real estate | 2004 |
| Vampscope Limited | Transport & logistics | 1985 |