| Portland Lombard Maintenance Services Ltd | Administrative & support | 2017 |
| Potaman UK Company Ltd | Health & social care | 2014 |
| Potato Pictures Limited | Information & communication | 2007 |
| Potn Limited | Wholesale & retail | 2002 |
| Potter Mortgages and Protection Limited | Financial services | 2025 |
| Potter Property Solutions Ltd | Real estate | 2021 |
| Powerplug Limited | Other services | 1986 |
| PPE Made Ltd | Wholesale & retail | 2020 |
| PR Food Holdings Limited | Professional & scientific | 1993 |
| Precision Access Scaffolding Services Limited | Construction | 2017 |
| Precision Brickwork Contractors Ltd | Construction | 2024 |
| Preece Consultants Limited | Professional & scientific | 1999 |
| Prestidge & SON Limited | Wholesale & retail | 2016 |
| Prestige Civil Engineering (Westbury) Limited | Construction | 1989 |
| Prestige Estates MK Ltd | Real estate | 2009 |
| Prestige Lawns Ltd | Administrative & support | 2012 |
| Prime Executive Stay Ltd | Hospitality | 2023 |
| Prime Pet Essentials Ltd | Wholesale & retail | 2023 |
| Prism Compliance AI Ltd | Professional & scientific | 2013 |
| Prism Ideas Compliance Services Ltd | Professional & scientific | 2024 |
| Prism Ideas Limited | Professional & scientific | 2000 |
| Prism Ideas Placements Ltd | Professional & scientific | 2024 |
| Prism Ideas Scicomms Ltd | Professional & scientific | 2024 |
| Prism Ideas Training Services Ltd | Professional & scientific | 2024 |
| Pro-Align Holdings Limited | Financial services | 2023 |
| Pro-Align Limited | Wholesale & retail | 1991 |
| Pro-Procure Business Development Limited | Administrative & support | 2016 |
| Pro-Vide Global Limited | Administrative & support | 2002 |
| Prodel Limited | Professional & scientific | 2009 |
| Product Data Pro Ltd | Information & communication | 2019 |
| Project Alpha Ltd | Health & social care | 2021 |
| Project Imola Limited | Wholesale & retail | 2004 |
| Proper Eatery Ltd | Extraterritorial | 2018 |
| Proper Food Production Ltd | Hospitality | 2018 |
| Property Matters (Albion) Ltd | Construction | 2010 |
| Protection Access Scaffolding Services Ltd | Construction | 2017 |
| Protective Security Risk Management Limited | Professional & scientific | 2019 |
| Protheo Ltd | Professional & scientific | 2018 |
| Provenance Brix & Mortar Limited | Hospitality | 2018 |
| Prysebros Limited | Administrative & support | 2012 |
| PSG Global Holdings Ltd | Financial services | 2021 |
| PSG Global Limited | Construction | 2010 |
| PTE Integrated Ltd | Professional & scientific | 2022 |
| PTP Interactive Ltd | Education | 2008 |
| Publier Media Group Ltd | Information & communication | 2024 |
| Pudsmoor Property Management Limited | Real estate | 2006 |
| Pulse Medical Care Solutions (UK) Limited | Wholesale & retail | 2023 |
| Purple Pitch PR Ltd | Administrative & support | 2018 |
| Purser Ventures Ltd | Professional & scientific | 2022 |
| Pury Hill Limited | Real estate | 1996 |
| Pury Investments Limited | Real estate | 2024 |
| Purywood Limited | Manufacturing | 2025 |
| Puxley Productions Limited | Information & communication | 2013 |
| Puxley Properties Limited | Real estate | 2018 |
| Pytec Limited | Administrative & support | 1999 |
| Qantums Ltd | Financial services | 2020 |
| Qdata Cloud House Limited | Information & communication | 2021 |
| QLM Holdings Limited | Financial services | 2025 |
| QLM Search Limited | Professional & scientific | 2022 |
| QLM Sport Ltd | Professional & scientific | 2026 |
| Qualico (U.K.) Limited | Professional & scientific | 2000 |
| Qyrixa Limited | Manufacturing | 2025 |
| R Evans Holdings Ltd | Other services | 2024 |
| R P Agencies Limited | Financial services | 1997 |
| R S Fabrications Ltd | Manufacturing | 2013 |
| R&D Assured Ltd | Professional & scientific | 2018 |
| R. a. Connections Limited | Manufacturing | 2002 |
| R.D. Landscapes Limited | Administrative & support | 2003 |
| R.E.W Consulting Ltd | Professional & scientific | 2010 |
| R.R.E.C. Limited | Other services | 1974 |
| R.S. Fabrications (Silverstone) Limited | Manufacturing | 2005 |
| R4 Advisory Limited | Professional & scientific | 2026 |
| R8222 Limited | Administrative & support | 2026 |
| Race Anywhere Ltd | Wholesale & retail | 2020 |
| Racing Point UK Limited | Professional & scientific | 2021 |
| Racingfotos Limited | Other services | 2007 |
| Racket Room Ltd | Arts & recreation | 2025 |
| Radclive Consulting Limited | Information & communication | 2014 |
| Radius Equity Nominees Limited | Financial services | 2014 |
| Ralf Wileman Ltd | Wholesale & retail | 2021 |
| Randall Parker Food Group Limited | Other services | 1995 |
| Ranworth Systems Ltd | Information & communication | 2015 |
| Rausa Property Ltd | Real estate | 2021 |
| RAW Landscaping and Design Limited | Administrative & support | 2014 |
| RAY Mallock Developments Limited | Administrative & support | 1990 |
| RBR Consultancy Ltd | Professional & scientific | 2022 |
| Rdltn Education Limited | Education | 2015 |
| RDP Professional Services Ltd | Professional & scientific | 2023 |
| Real Estate Resource Limited | Professional & scientific | 2020 |
| Red Barn Training Limited | Education | 2014 |
| Red Sky Property Solutions Ltd | Real estate | 2024 |
| Redmoor Ashalls LLP | | 2011 |
| Redwood Systems Limited | Professional & scientific | 2026 |
| Reference Sounds Limited | Wholesale & retail | 2010 |
| Reform Fire Ltd | Professional & scientific | 2010 |
| Reindeer Court Management Company Limited | Households | 2019 |
| Relatus Ltd | Professional & scientific | 2006 |
| Relocate Property Reports Ltd | Households | 2023 |
| Renco Building Services Ltd | Construction | 2019 |
| Reptile Retail Bletchley Limited | Wholesale & retail | 2011 |