| Pdsvale (UK) Limited | Truro | 2005 |
| Peace Wood Quarry Limited | Huddersfield | 2011 |
| Peacegold CIC | Bishop Auckland | 2024 |
| Peacegold Trading Limited | Bishop Auckland | 2026 |
| Peak Aggregates Limited | Bakewell | 2021 |
| Peak Crisis Management Consultancy Limited | Inverurie | 2021 |
| Peak Longton Ltd | Oldham | 2025 |
| Peak Minerals Ltd | Sheffield | 2015 |
| Peak Nickel Limited | Sheffield | 2017 |
| Peak Technology Metals Limited | Newcastle Upon Tyne | 2018 |
| Peak-Amc- Ltd | Buxton | 2024 |
| Peakstone Aggregates Limited | Rotherham | 2003 |
| Peap OIL and GAS Company Limited | London | 2025 |
| Pearson Mining Supplies Ltd | Huddersfield | 2017 |
| Peateater Limited | Isle Of Lewis | 2013 |
| Pebs Limited | | 2004 |
| Peer-Group International Ltd. | Selkirk | 2002 |
| Pegasus Royalties Limited | London | 2025 |
| Pegasus Wind Energy Limited | Wingate | 2024 |
| Pegseo Stone Ltd | Colchester | 2020 |
| Pelham Consult Limited | South Shields | 2013 |
| Pelican Geographics Ltd | Hampshire | 2000 |
| Pelorus Minerals Limited | London | 2021 |
| Pembridge Resources PLC | London | 2010 |
| Pembrokeshire Trout & Salmon Limited | West Glamorgan | 1984 |
| Pendle Energy Consultants Limited | Aberdeen | 2019 |
| Penfro Subsea Services Ltd | Keighley | 2019 |
| Penhale Ventures Limited | London | 2004 |
| Penhurst Global Resources Limited | London | 2025 |
| Peninsula Uranium Limited | Birmingham | 2015 |
| Penlea Consultants Ltd | Aberdeen | 2007 |
| Penningtons Quarry Limited | Carnforth | 2017 |
| Pennpetro Energy PLC | London | 2016 |
| Pensana PLC | London | 2019 |
| Penta Energy Ltd | London | 2024 |
| Pentagon Computers Limited | London | 2000 |
| Pentex Italia Limited | London | 1985 |
| Penthaven Services Limited | | 2007 |
| Perchstone & Graeys Consulting Ltd | London | 2021 |
| Percy Pickard (Merchants) Limited | Bradford | 1959 |
| Perelvo (UK) Crop Nutrition Ltd | London | 2024 |
| Perenco Chergui OIL & GAS Limited | London | 2025 |
| Perenco CUU Long Limited | London | 2003 |
| Perenco GAS (UK) Limited | London | 1962 |
| Perenco North Sea Limited | Edinburgh | 2005 |
| Perenco OIL and GAS Colombia Limited | London | 1984 |
| Perenco SNS Limited | London | 2011 |
| Perenco UK Infrastructure Limited | London | 2011 |
| Perenco UK Limited | London | 2003 |
| Perenti UK Limited | London | 2019 |
| Performance Improvements (PI) Limited | Aberdeen | 2023 |
| Pergendum Ltd | Peterhead | 2020 |
| Peridot Energy Consultants Limited | Cardiff | 2017 |
| Perigean Offshore Ltd | Brechin | 2018 |
| Perigean Subsea (Scotland) Ltd | Brechin | 2022 |
| Permian Resources Corporation Limited | London | 2020 |
| Perrisla Ltd. | Kelty | 2015 |
| Persuk Energy Ltd | London | 2026 |
| Perton Quarry Limited | Cheltenham | 2009 |
| Peseco Limited | Aberdeen | 1998 |
| Pet Resource Limited | Aberdeen | 2007 |
| Petans Limited | Norwich | 1984 |
| Peteq Ltd | Twickenham | 2015 |
| Peter Bennie Limited | Kettering | 1975 |
| Peter Fitzpatrick Limited | Newry | 1983 |
| Peto Svcs Limited | Great Yarmouth | 2013 |
| Petrafiz Ltd. | Cornwall | 1997 |
| Petrally Services Limited | Lowestoft | 2014 |
| Petreco International (Middle East) Limited | London | 1997 |
| Petrenol Limited | Bangor | 2005 |
| Petrichor Energy UK Limited | Stroud | 2014 |
| Petriva Limited | Sheffield | 2017 |
| Petro Operations Limited | Keith | 2025 |
| Petro Pulse Ltd | Doncaster | 2025 |
| Petro Winch Limited | London | 1987 |
| Petro-Celtex Consultancy Limited | Haslemere | 1997 |
| Petro-Ella Limited | Muir Of Ord | 2014 |
| Petro-Geomechanics Limited | London | 2019 |
| Petro-Legal Limited | Oxted | 2012 |
| Petroc Ltd | Didcot | 2021 |
| Petrodec UK Limited | London | 2019 |
| Petroexperts Ltd | Westhill | 2025 |
| Petrofac (Malaysia-Pm 304) Limited | London | 1997 |
| Petrofac Facilities Management Limited | Aberdeen | 1981 |
| Petrofac Training Group Limited | Aberdeen | 2000 |
| Petrogas E&P UK Limited | London | 2004 |
| Petrogas North Sea Limited | London | 2005 |
| Petrohint Limited | London | 2010 |
| Petrolco Ltd | Cardiff | 2021 |
| Petrolegal and Commercial Services Ltd | Haslemere | 2010 |
| Petroleum Assets Development Ltd | Hoddesdon | 2012 |
| Petroleum Atlas Limited | London | 2004 |
| Petroleum Enterprises Ltd | Newton Hall | 2019 |
| Petroleum Geo-Services (UK) Limited | Weybridge | 1993 |
| Petroleum Geosciences Consultancy Limited | Colwyn Bay | 2016 |
| Petroleum Industry Engineering Overseas Limited | Norfolk | 2000 |
| Petroligem Limited | London | 2013 |
| Petrolium Holding Ltd | London | 2022 |
| Petromaine Consultants Limited | Laurencekirk | 1991 |
| Petroman (UK) Ltd | London | 2014 |