| Pier Consultants Limited | Professional & scientific | 2015 |
| Piggotts Family Butchers Limited | Wholesale & retail | 1999 |
| Pikesley (Woburn Sands) Limited | Wholesale & retail | 1969 |
| Pilates First Limited | Arts & recreation | 2017 |
| Pilgrims Landing Management Company Limited | Real estate | 2003 |
| Pilgrims Publishing Ltd | Information & communication | 2021 |
| Pillar Capital Estates Ltd | Real estate | 2026 |
| Pimentel and Partners Ltd | Professional & scientific | 2020 |
| Pincer Ltd | Information & communication | 2022 |
| Pinch of Web Limited | Information & communication | 2009 |
| Pinebank Residents Company (Gamlingay) Limited | Households | 1982 |
| Pinerock Investments Ltd | Financial services | 2024 |
| Pingu Telecoms Ltd | Information & communication | 2023 |
| Pink Circle Consulting Limited | Manufacturing | 2024 |
| Pink Crest Consulting Limited | Professional & scientific | 2026 |
| Pink Dolphin Music Ltd | Manufacturing | 2012 |
| Pink Sulfur Ltd | Wholesale & retail | 2026 |
| Pinkney Investments Ltd | Real estate | 2021 |
| Pinnacle Building Services Ltd | Construction | 2025 |
| Pinnacle Design Ltd | Construction | 2017 |
| Pinnacle Wealth Planning Limited | Administrative & support | 2012 |
| Pinpoint Partners LLP | | 2011 |
| Pioneer Aston Limited | Administrative & support | 2020 |
| Pioneer Contractors Ltd | Construction | 2025 |
| Pioneer Estates Group Ltd | Real estate | 2025 |
| Pioneer LED Ltd | Manufacturing | 2017 |
| Pioneer Midlands Property Ltd | Real estate | 2016 |
| Pioneer Planting Ltd | Administrative & support | 2024 |
| Pioneer Real Estate Ltd | Households | 2022 |
| Pioneer Sealants Ltd | Construction | 2020 |
| Pioneerdx Limited | Professional & scientific | 2024 |
| Pioneering Innovations Limited | Professional & scientific | 2003 |
| Piotr DYL Ltd | Wholesale & retail | 2019 |
| Piotr Wiater Ltd | Wholesale & retail | 2018 |
| Piotrip Ltd | Transport & logistics | 2020 |
| Pipelines Plumbing & Heating Limited | Construction | 2023 |
| Piper & EVE Bridal Ltd | Wholesale & retail | 2023 |
| Pippa Green Limited | Professional & scientific | 2009 |
| Piraba's Limited | Wholesale & retail | 2025 |
| Pirakalai M Vision Ltd | Health & social care | 2025 |
| Pitch Perfect Robotics Ltd | Agriculture & fishing | 2026 |
| Piters Cars Ltd | Wholesale & retail | 2022 |
| Pitstop Garage MK Limited | Wholesale & retail | 2024 |
| Pivot 1ST Ltd | Information & communication | 2024 |
| Pivotal Design Ltd | Professional & scientific | 2023 |
| Pixara Group Ltd | Manufacturing | 2026 |
| Pixel Precision Ltd | Information & communication | 2024 |
| Pixel Time Ltd | Information & communication | 2024 |
| Pixelated Holdings Ltd | Financial services | 2022 |
| Pizza Piccolo Limited | Hospitality | 2021 |
| PJ Consultancy Group Limited | Professional & scientific | 2023 |
| PJ Drone Services Ltd | Other services | 2021 |
| PJ Investment Assets Ltd | Real estate | 2021 |
| PJA Music Consultancy Limited | Professional & scientific | 2014 |
| Pjay IT Services Ltd | Information & communication | 2016 |
| PJH Co. Facilities Ltd | Construction | 2022 |
| PJH Co. Ltd | Construction | 2014 |
| PJH Co. Services Ltd | Construction | 2022 |
| PJH Plumbing Limited | Construction | 2022 |
| PJH Property Developments Ltd | Real estate | 2018 |
| PJS Communications Limited | Professional & scientific | 2007 |
| PJS Production Services Ltd | Professional & scientific | 2014 |
| PJS Trading Limited | Real estate | 1994 |
| PK Auto Doors Ltd | Professional & scientific | 2024 |
| PK Construction and Consulting Limited | Construction | 2026 |
| PK Decorating Services Ltd | Construction | 2017 |
| PK Food Services Limited | Hospitality | 2025 |
| PK International Ltd | Professional & scientific | 2019 |
| PKS Services Fleet & Cars Ltd | Wholesale & retail | 2011 |
| PL Machinery Services & Sales Limited | Wholesale & retail | 2005 |
| PLA Events Limited | Arts & recreation | 2013 |
| Plan Design & Build : Specialist Works Ltd | Construction | 2022 |
| Plan Design & Build Ltd | Construction | 2018 |
| Plancentric Global Limited | Information & communication | 2014 |
| Plancentric Limited | Information & communication | 2010 |
| Plane Simple Training Ltd | Transport & logistics | 2024 |
| Planet (Boutique) Clothing 93 Ltd | Wholesale & retail | 2010 |
| Planet Mermaid Ltd | Wholesale & retail | 2014 |
| Planet MX5 Ltd | Wholesale & retail | 2025 |
| Planly AI Ltd | Public administration | 2025 |
| Planning Initiatives Limited | Professional & scientific | 1996 |
| PLANNING38 Ltd | Professional & scientific | 2026 |
| Plant Auction Limited | Professional & scientific | 2008 |
| Plant Based WOD Limited | Other services | 2019 |
| Plant Pro Ltd | Wholesale & retail | 2012 |
| Planthaul Limited | | 1971 |
| Plantspace Group Limited | Real estate | 2026 |
| Plas Dinas Properties Limited | Other services | 1963 |
| Plasterer Matt Ltd | Professional & scientific | 2025 |
| Plastic Profile Supplies Ltd | Wholesale & retail | 2025 |
| Plastic Systems Limited | Manufacturing | 2006 |
| Plastics Window Federation | Other services | 1990 |
| Plastics Window Guarantee Limited | Financial services | 1989 |
| Plastoplan Polymers Limited | Wholesale & retail | 2022 |
| Plateau Care Ltd | Health & social care | 2016 |
| Platinum Garden Care Ltd | Administrative & support | 2025 |
| Platinum Hvac Services Limited | Construction | 2022 |
| Platinum People Solutions Limited | Professional & scientific | 2025 |
| Play in the Grey Products Ltd | Wholesale & retail | 2022 |
| Playset Games Limited | Information & communication | 2026 |