| Professional Divers Equipment Ltd | Manufacturing | 2023 |
| Professional Financial Intermediary Services Limited | Professional & scientific | 2016 |
| Professional Learning and Leadership Education Wales Dysgu Proffesiynol AC Arweinyddiaeth Addysg Cymru | Education | 2018 |
| Professional Peopl Ltd | Administrative & support | 2019 |
| Professional Program Solutions Limited | Professional & scientific | 2020 |
| Professional Services Ltd | Real estate | 2025 |
| Professor Kechuang International Group Holdings Limited | Extraterritorial | 2019 |
| Proficient Partners Limited | Construction | 2016 |
| Profil Management Limited | Other services | 2017 |
| Profilex Properties Limited | Real estate | 2007 |
| Profirentcars Europe Ltd. | Professional & scientific | 2017 |
| Profit Surge Ltd | Hospitality | 2016 |
| Profitpal Ltd | Information & communication | 2023 |
| Profluides Ltd | Professional & scientific | 2025 |
| Profound Recruitment Ltd | Administrative & support | 2018 |
| Profusion FX Ltd | Education | 2018 |
| Proglomerate Ltd | Financial services | 2023 |
| Progneur Technologies Limited | Information & communication | 2014 |
| Programme Control Group Ltd | Professional & scientific | 2021 |
| Progressio Tuition Limited | Education | 2021 |
| Progressive Accountants & Tax Specialists Limited | Professional & scientific | 2025 |
| Progressive Homecare Services Limited | Health & social care | 2019 |
| Progressive Legal Solutions Limited | Information & communication | 2022 |
| Progymgear Ltd | Wholesale & retail | 2025 |
| Prohab Performance Limited | Health & social care | 2012 |
| Prohealth Consultancy Ltd | Administrative & support | 2023 |
| Proinstallations Ltd | Construction | 2022 |
| Project 12 Construction Limited | Construction | 2019 |
| Project 17 Construction Ltd | Real estate | 2021 |
| Project 216 Ltd | Professional & scientific | 2019 |
| Project 55 Ltd | Professional & scientific | 2018 |
| Project a Design Ltd | Wholesale & retail | 2023 |
| Project BLU Ltd | Wholesale & retail | 2017 |
| Project Clips Ltd | Wholesale & retail | 2022 |
| Project Eclosia Ltd | Manufacturing | 2025 |
| Project Eirlys Ltd | Energy | 2026 |
| Project Engineering London Ltd | Construction | 2013 |
| Project Gilroy Ltd | Professional & scientific | 2019 |
| Project Green (Holdco) Limited | Financial services | 2026 |
| Project Group Holdings Ltd | Wholesale & retail | 2019 |
| Project Influence Ltd | Information & communication | 2025 |
| Project Jupiter Online Limited | Information & communication | 2016 |
| Project Nouvelle Limited | Construction | 2024 |
| Project Office Resources & Tools (Port) Ltd | Professional & scientific | 2018 |
| Project One-X Ltd | Administrative & support | 2023 |
| Project Planning Management Ltd | Construction | 2018 |
| Project Property Accounts Limited | Real estate | 2024 |
| Project Property Management Limited | Households | 2020 |
| Project Pyro Limited | Information & communication | 2023 |
| Project Three Developments Limited | Construction | 2017 |
| Project Three Holdings Ltd | Real estate | 2025 |
| Project Two Point OH! Ltd | Health & social care | 2025 |
| Project X Tech Ltd | Information & communication | 2024 |
| PROJECT641 Ltd | Households | 2020 |
| Projection Heaven Ltd | Wholesale & retail | 2019 |
| Projectory Ltd | Information & communication | 2011 |
| Projectprovision Ltd | Professional & scientific | 2023 |
| Prolibya Limited | Administrative & support | 2018 |
| Proline Computer Ltd | Wholesale & retail | 2025 |
| Proline Concepts Ltd | Construction | 2024 |
| Proline Enterprises Ltd | Other services | 2019 |
| Proline Internet Limited | Wholesale & retail | 2004 |
| Proline Retail Limited | Wholesale & retail | 2017 |
| Prolines NI Enterprises Ltd | Manufacturing | 2020 |
| Prologue Capital Limited | Administrative & support | 2005 |
| Prolokes | Professional & scientific | 2024 |
| Prolonus | Professional & scientific | 2024 |
| Promagem Limited | Wholesale & retail | 2018 |
| Promanage Lettings Ltd | Households | 2023 |
| Promatch Consulting Ltd | Administrative & support | 2017 |
| Promatrix Technologies Limited | Information & communication | 2025 |
| Promech Developments Ltd | Construction | 2024 |
| Promech Systems Ltd | Construction | 2020 |
| Promela Limited | Transport & logistics | 2019 |
| Prometheus Developments Ltd | Construction | 2021 |
| Prometheus Tech Ltd | Information & communication | 2023 |
| Prometum Inc. Ltd | Information & communication | 2018 |
| Promig Alliance PC | | 2018 |
| Promise Property Partners Limited | Households | 2025 |
| Promising Climbing Limited | Wholesale & retail | 2025 |
| Promixx Limited | Manufacturing | 2011 |
| Promo - Cymru Ltd | Education | 1984 |
| Promo Market PC | | 2014 |
| Promo Trendz Limited | Wholesale & retail | 2025 |
| Promo-Cymru Trading Limited | Information & communication | 2007 |
| Promox Limited | Professional & scientific | 2025 |
| Prompt Contract Services Ltd | Hospitality | 2019 |
| Pronto Healthcare Limited | Extraterritorial | 2018 |
| Pronto Pronto Services Limited | Transport & logistics | 2017 |
| Pronto Solutions Ltd | Wholesale & retail | 2018 |
| Pronto-Co Limited | Wholesale & retail | 2024 |
| Proof Politic Ltd | Professional & scientific | 2024 |
| Propaint Spray Solutions Ltd | Construction | 2024 |
| Propatir Ltd | Real estate | 2026 |
| Propco Developments (Dinas Powys) Limited | Construction | 2023 |
| Propco Developments (Lamby Way) Limited | Construction | 2014 |
| Propcot Ltd | Real estate | 2022 |
| Propel Nation CYF | Other services | 2018 |
| Propel Nation Homes CYF | Real estate | 2026 |
| Propel Project Management Ltd | Construction | 2024 |