| PIT Stop U Ltd | Wholesale & retail | 2026 |
| Pitch Perfect (GC) Limited | Construction | 2017 |
| Pitch Perfect Design & Build Limited | Construction | 2022 |
| Pitstop Motors (Swindon) Ltd | Wholesale & retail | 2017 |
| Pivot Psychological Services Ltd | Professional & scientific | 2022 |
| Pixel Crew Ltd | Information & communication | 2025 |
| Pixel Pixel Ltd | Information & communication | 2014 |
| Pizgo Limited | Hospitality | 2019 |
| Pizza Revolt Ltd | Hospitality | 2025 |
| Pizzabi Ltd | Wholesale & retail | 2025 |
| PJ Plant Hire (Oxon) Limited | Wholesale & retail | 2008 |
| PJ Transport (Swindon) Limited | Transport & logistics | 2015 |
| PJG Utilities Ltd | Construction | 2026 |
| PJK Signalling Limited | Professional & scientific | 2020 |
| PJL Services & Storage Ltd | Construction | 2023 |
| PJM & Partners LLP | | 2024 |
| PJS Autos (Swindon) Ltd. | Wholesale & retail | 1995 |
| PJS Fire Protection Limited | Construction | 2008 |
| PK Tennis Limited | Arts & recreation | 2017 |
| PKA a Holdings Limited | Administrative & support | 2017 |
| PKK Limited | Professional & scientific | 2001 |
| PKP Property Ltd | Real estate | 2025 |
| PKR Anisk Local Shop Limited | Wholesale & retail | 2021 |
| PKR Composites Ltd | Professional & scientific | 2025 |
| PL Trucking Limited | Transport & logistics | 2016 |
| PL20 Limited | Hospitality | 2025 |
| Plaisir DE Manger Ltd | Manufacturing | 2025 |
| Plaister Autos Limited | Wholesale & retail | 2024 |
| Plan My Business Ltd | Professional & scientific | 2021 |
| Planenvi Ltd | Professional & scientific | 2026 |
| Planet Gardens Ltd | Administrative & support | 2014 |
| Planet Nails Ltd | Other services | 2025 |
| Planet Pitta Limited | Hospitality | 2024 |
| Planetaid Limited | Wholesale & retail | 1999 |
| Planetor Limited | Information & communication | 2024 |
| Planned Link Ltd | Information & communication | 2014 |
| Planned Packaging Films Limited | Administrative & support | 2004 |
| Planned Packaging Limited | Wholesale & retail | 1968 |
| Planned Safety Systems Limited | Professional & scientific | 2025 |
| Plant Department Ltd | Manufacturing | 2018 |
| Plant for Peace (Holding) Ltd | Manufacturing | 2010 |
| Plant for People Mining Ltd | Mining & quarrying | 2025 |
| Plant School Limited | Professional & scientific | 2025 |
| Plant Tech Swindon Ltd | Professional & scientific | 2018 |
| Plastic Card Solutions Limited | Manufacturing | 2003 |
| Platinum Cooling Systems Ltd | Manufacturing | 2012 |
| Platinum Exec Transfers Ltd | Transport & logistics | 2023 |
| Platinum Hands Barbers Ltd | Other services | 2024 |
| Platinum Rose Hair Limited | Other services | 2025 |
| Playsteps Kembrey Limited | Education | 2013 |
| Playsteps Limited | Administrative & support | 2005 |
| Playtime London LLP | | 2019 |
| Plaza 21 Residential (Management) Company Limited | Households | 2000 |
| PLAZA64 Limited | Real estate | 2024 |
| Pleatfold Limited | Professional & scientific | 2025 |
| Pleir Consultancy Limited | Professional & scientific | 2023 |
| PLM SW Transport Ltd | Transport & logistics | 2021 |
| Plotkin & Chandler Ltd | Information & communication | 2016 |
| Plumbheat Services Ltd | Construction | 2019 |
| Plus UP Consulting Ltd | Professional & scientific | 2023 |
| Plyhaus Ltd | Manufacturing | 2025 |
| Plymouth Centre Electric Forecourt Limited | Energy | 2020 |
| Plymouth Sound (UK) Holdings LP | | 2013 |
| PM UK Publishing Ltd | Extraterritorial | 2016 |
| Pmai Accounting Services Ltd | Professional & scientific | 2025 |
| PMC Contracts Limited | Construction | 2003 |
| PMJ Logistics Ltd | Transport & logistics | 2021 |
| PMP Management Limited | Professional & scientific | 2024 |
| Pndt Limited | Professional & scientific | 2021 |
| PNJ Consultancy Limited | Professional & scientific | 2020 |
| PNS Properties Ltd | Real estate | 2022 |
| Podpadstudios Ltd | Other services | 2015 |
| Pogmac Ltd | Professional & scientific | 2024 |
| POINT2POINT IT Limited | Other services | 2016 |
| Pointe Ahead Manchester Ltd | Arts & recreation | 2026 |
| Pointe Perfection Ltd | Wholesale & retail | 2013 |
| POINTS2WORK Limited | Professional & scientific | 2004 |
| POL Consulting Ltd | Construction | 2024 |
| Polak Peter Transport Ltd | Transport & logistics | 2019 |
| Polar Rendering Ltd | Construction | 2016 |
| Polemology Limited | Professional & scientific | 2023 |
| Poles Apart AP Ltd | Education | 2021 |
| Polish Community Centre Limited | Transport & logistics | 2015 |
| Polka DOT Stripe Ltd | Other services | 2020 |
| Polydhill Limited | Administrative & support | 2025 |
| Pomegranate Properties (Swindon) Limited | Agriculture & fishing | 2019 |
| Pomegranate Properties SW Limited | Agriculture & fishing | 2021 |
| Pomphrey and James Ltd | Real estate | 2018 |
| Pontoon Security Services Ltd | Professional & scientific | 2023 |
| Pooleys Solicitors LLP | | 2010 |
| POP the Bottle Ltd | Hospitality | 2020 |
| Popp's Kitchen Limited | Hospitality | 2025 |
| Poppin Brands Limited | Wholesale & retail | 2018 |
| Poppy Fields (Swindon) Residents Limited | Households | 2016 |
| Popsicle Tickets Ltd | Wholesale & retail | 2022 |
| Portable Quick Co Pro Ltd | Wholesale & retail | 2025 |
| Porte Developments Ltd | Construction | 2025 |
| Porter Construction (Bicester) Ltd. | Wholesale & retail | 1988 |
| Porthdinlleyn Harbour Company (the) | Transport & logistics | 1906 |
| Porthtowan Beach Cafe Limited | Hospitality | 2016 |