| Powerx International Equipment Ltd | Coventry | 2016 |
| Powerx Spares & Service Limited | Coventry | 2010 |
| Powys Drilling Services Limited | Builth Wells | 2008 |
| Powys Stone Supplies Limited | Powys | 2006 |
| Pozzolan Limited | Westcott | 2017 |
| PP O'Connor Aggregates Limited | Bury | 2016 |
| PP OIL & GAS (Indonesia-Jabung) Limited | | 1996 |
| PPL Europe E&P Limited | London | 2003 |
| PPS Offshore Ltd | Paisley | 2025 |
| PR Bolting Limited | Gateshead | 2024 |
| PR Stones International Ltd | London | 2025 |
| Praedari Investments Ltd | London | 2020 |
| Praefectus Well Supervision Limited | Battle | 2015 |
| Praemurcia Limited | Eastleigh | 2022 |
| Prax Exploration & Production PLC | Birmingham | 2019 |
| Prax Hurricane (Strathmore) Limited | London | 2017 |
| Prax Hurricane (Whirlwind) Limited | London | 2017 |
| Prax Hurricane Basement Limited | London | 2011 |
| Prax Hurricane GLA Limited | London | 2017 |
| Prax Hurricane Group Limited | London | 2011 |
| Prax Hurricane GWA Limited | London | 2017 |
| Prax Hurricane Holdings Limited | London | 2017 |
| Prax Hurricane Petroleum Limited | London | 2011 |
| Prax Upstream Limited | London | 2004 |
| Precious Metals Technical Consulting Limited | London | 2013 |
| Precision Access Compliance Limited | Heywood | 2024 |
| Precision Inspection Limited | Peterhead | 2010 |
| Precision Rigging & Lifting Limited | Lowestoft | 2011 |
| Prektal Co. Contracting Engineering Consultations Petroleum Services and Trading Ltd | London | 2025 |
| Prema Plus Holdings Ltd | Burscough | 2023 |
| Prema Plus Limited | Ormskirk | 2021 |
| Prema Plus OIL & GAS Limited | Ormskirk | 2025 |
| Premier Diamond Drilling Services Limited | High Wycombe | 2004 |
| Premier Lime & Stone Company Limited | Durham | 1956 |
| Premier OIL Aberdeen Services Limited | London | 1974 |
| Premier OIL and GAS Services Limited | London | 1997 |
| Premier OIL Andaman I Limited | London | 2010 |
| Premier OIL Andaman Limited | London | 2013 |
| Premier OIL ANS Limited | London | 2006 |
| Premier OIL Barakuda Limited | London | 2004 |
| Premier OIL E&P UK EU Limited | London | 1994 |
| Premier OIL E&P UK Limited | London | 1992 |
| Premier OIL Exploration Limited | Edinburgh | 1939 |
| Premier OIL FAR East Limited | Birmingham | 1973 |
| Premier OIL Group Limited | 20 Castle Terrace | 1934 |
| Premier OIL Holdings Limited | London | 1998 |
| Premier OIL Mexico Holdings Limited | London | 2012 |
| Premier OIL Mexico Investments Limited | London | 2012 |
| Premier OIL South Andaman Limited | London | 1980 |
| Premier OIL UK Limited | Edinburgh | 1971 |
| Premier OIL Vietnam 121 Limited | London | 2012 |
| President Energy (UK) Limited | Leeds | 2003 |
| President Energy Investments (Paraguay) Limited | Leeds | 2021 |
| President Energy Paraguay Limited | Leeds | 2012 |
| President Energy Pirity Limited | Leeds | 2014 |
| President Engineering Limited | Cardiff | 2024 |
| Press Leakage Control Services Limited | Wartell Bank, Kingswinford | 1989 |
| Pressure Engineering UK Ltd | Glasgow | 2023 |
| Pressure Equipment Consultancy Limited | Aberdeen | 2011 |
| Pressure Inspection Limited | Barnsley | 2022 |
| Prestige Access Worldwide Ltd | St. Austell | 2020 |
| Prestige Portfolio Management Limited | London | 2017 |
| Prestige Rigging & Lifting Services Ltd | Washington | 2019 |
| PRF (Preesall) Ltd | Blackpool | 2021 |
| Price Energy Advisory Ltd | Wimborne | 2019 |
| Prieuree Electrique Limited | Stockton-On-Tees | 2016 |
| Primanav Ltd | London | 2023 |
| Primary Access Solutions Ltd | Hull | 2015 |
| Primary Resources Limited | Bracknell | 2011 |
| Prime AEP Limited | Bristol | 1935 |
| Prime Global Corporation Ltd | Wolverhampton | 2025 |
| Prime Global Energies Limited | Bristol | 1918 |
| Prime Global OIL GAS Services Ltd | London | 2020 |
| Prime Horizontal International Limited | Glasgow | 2009 |
| Prime Oceania Energy Resources Limited | London | 2023 |
| Prime Readymix Concrete Ltd | Norwich | 2020 |
| Prins Chemical Ltd | Coventry | 2025 |
| Pritch Energies Ltd | London | 2023 |
| Pro SUB Engineering Ltd. | Dundee | 2016 |
| Proactive Drilling Management Limited | Stockton On Tees | 1996 |
| Process Limited | Coventry | 1991 |
| Process Safety & Risk Consulting Ltd. | Warrington | 2018 |
| Processing, Excavation and Construction Equipment Hire (UK) Limited | Chesterfield | 2017 |
| Procurement Professionals (UK) Ltd | Stockton On Tees | 2014 |
| Prodtech Services Ltd | London | 2024 |
| Production Process Support Services Ltd | Wick | 2022 |
| Production Services Network (UK) Limited | Aberdeen | 2005 |
| Productionquest Limited | London | 2003 |
| Profen Industrial Supply Ltd | Hayes | 2022 |
| Profound Drilling Limited | Aberdeen | 2013 |
| Progressive Energy Partners Ltd | Bognor Regis | 2016 |
| Progwin Limited | London | 2024 |
| Project Chile (EU) Limited | London | 2024 |
| Project Development International Limited | Manchester | 2003 |
| Prolific Mining Corporation Ltd | London | 2025 |
| Prolog Supply & Services Limited | Stockport | 2006 |
| Pronoeo Ltd | 139 Fountainbridge | 2014 |
| Propellio Limited | London | 2012 |
| Propulsion Trading and Supplies Ltd | Preston | 2025 |
| Prosafe Offshore Limited | Bristol | 1997 |