| PSI PI Group Limited | Professional & scientific | 2009 |
| PSI Thinking Limited | Professional & scientific | 2009 |
| PSK SCM Consultancy Limited | Professional & scientific | 2015 |
| Psycho Bunny Limited | Health & social care | 2025 |
| Ptca Holdings Ltd | Hospitality | 2018 |
| Ptech Group Ltd | Administrative & support | 2025 |
| Pugh Williams Group Ltd | Information & communication | 2023 |
| Pulcinella Food Ltd | Hospitality | 2022 |
| Pull UP Basketball Ltd | Wholesale & retail | 2023 |
| Pullens Consulting Ltd | Construction | 2018 |
| Pullens Investments Ltd | Real estate | 2022 |
| Pump House (London Road) Limited | Households | 2019 |
| Purchase Box Ltd | Information & communication | 2022 |
| Pure Beauty by V.D. Ltd | Other services | 2020 |
| Pure Breeze Ltd | Energy | 2019 |
| Pure Earth Collection Ltd | Manufacturing | 2017 |
| Pure Earth Holdings Limited | Manufacturing | 2026 |
| Purely Personnel Ltd | Administrative & support | 2013 |
| Purple Friday Ltd | Administrative & support | 2015 |
| Purple Marketing Communications Limited | Professional & scientific | 2008 |
| Purple Monday Limited | Construction | 2017 |
| Purple Monkey Limited | Arts & recreation | 2012 |
| Purple Planet IT Limited | Information & communication | 2015 |
| PV Lakshmi UK Ltd | Information & communication | 2019 |
| Pwgap Ltd | Health & social care | 2011 |
| PX Moon Media Ltd | Professional & scientific | 2023 |
| Q Hearts London Ltd | Other services | 2026 |
| Q&A Distribution UK Ltd | Wholesale & retail | 2025 |
| QED Productions Limited | Other services | 1986 |
| QS Property Investments Ltd | Real estate | 2020 |
| Qualitas Technology Limited | Professional & scientific | 1993 |
| Quality Equestrian Services Ltd | Agriculture & fishing | 2019 |
| Quant Trading Capital Limited | Information & communication | 2023 |
| Quant Trading Consultancy Limited | Professional & scientific | 2023 |
| Quantessa Ltd | Information & communication | 2025 |
| Quantfidential Limited | Information & communication | 2017 |
| Quantum Prime Services Ltd | Professional & scientific | 2024 |
| Quarm Solutions Limited | Information & communication | 2004 |
| Qubis Technologies Ltd | Manufacturing | 2018 |
| Queenscote Limited | Administrative & support | 1995 |
| Questmoor Limited | Wholesale & retail | 1980 |
| Qyrexia Ltd | Information & communication | 2026 |
| R & C Haulage Limited | Water & waste | 2012 |
| R Brincat Engineering Limited | Administrative & support | 2013 |
| R C Electrical Services Ltd | Construction | 2025 |
| R Castle Limited | Construction | 2018 |
| R J Engineering Solutions Limited | Professional & scientific | 2010 |
| R OIL Essence Limited | Wholesale & retail | 2020 |
| R&B Trading (London) Ltd | Other services | 2018 |
| R. Bailey Carpentry & Joinery Ltd | Construction | 2012 |
| R. Richards Limited | Education | 2004 |
| Race Used Ltd | Wholesale & retail | 2017 |
| Rachel's Foods Ltd | Hospitality | 2023 |
| Rachmas Financial Management Ltd | Professional & scientific | 2010 |
| Radha Rani Smiles Ltd | Professional & scientific | 2024 |
| Radheya Ltd | Health & social care | 2019 |
| Radius Union Ltd | Manufacturing | 2022 |
| Radnav Ltd | Information & communication | 2022 |
| Ragno Ltd | Hospitality | 2019 |
| Raid Media Ltd | Administrative & support | 2016 |
| Rainbowgiles Limited | Professional & scientific | 2011 |
| Raine and Co (ST Albans) Ltd | Real estate | 2013 |
| Raine and Co. (Oaklands) Ltd | Administrative & support | 2015 |
| Raine Building Ltd. | Construction | 2026 |
| Raised Ltd | Administrative & support | 2018 |
| Raised Nominees Ltd | Professional & scientific | 2020 |
| RAK Technologies Ltd | Information & communication | 2025 |
| RAK Thaimassage Limited | Other services | 2017 |
| Ranec Consulting Limited | Professional & scientific | 2017 |
| Range Homes Limited | Real estate | 2006 |
| Rapid Car Rentals Limited | Administrative & support | 2003 |
| Rapstrap Limited | Wholesale & retail | 2006 |
| Rawaz Properties Ltd | Real estate | 2024 |
| RAY J Consulting Ltd | Administrative & support | 2010 |
| Rayan Property Investments Limited | Real estate | 2013 |
| Raymond Court Residents Management Company Limited | Households | 1985 |
| RBC Analytics Ltd | Information & communication | 2025 |
| RBR Investment Properties Ltd | Real estate | 2020 |
| RC International Ltd | Wholesale & retail | 2025 |
| RC Medical Services Ltd | Health & social care | 2014 |
| RC Waste Limited | Water & waste | 2023 |
| RCS of London Limited | Transport & logistics | 2009 |
| RDS Creative Ltd | Information & communication | 2013 |
| Reactive Roofing (UK) Limited | Construction | 2009 |
| Read & Daughters Ltd | Wholesale & retail | 2019 |
| Read & Partners Consultancy Ltd | Administrative & support | 2024 |
| Ready Controls Limited | Professional & scientific | 2017 |
| Real Close Limited | Real estate | 2021 |
| Realtime Civil Engineering Limited | Construction | 1987 |
| Realtime Civil Engineering London Limited | Administrative & support | 2013 |
| Realtime Technical Services Ltd | Professional & scientific | 2017 |
| Reckless Music Limited | Arts & recreation | 2022 |
| Red Bear Investments Limited | Real estate | 2025 |
| Red Lion Port Talbot Ltd | Real estate | 2021 |
| Redalpine Venture Partners Limited | Professional & scientific | 2024 |
| Redemore Homes Limited | Construction | 2005 |
| Redsure Ltd | Professional & scientific | 2003 |
| Redwood Contract Management Limited | Professional & scientific | 2016 |
| Redwood Homes SE UK Ltd | Real estate | 2024 |
| Redz Hair Crazy Ltd | Other services | 2024 |