| Plaster Masters Limited | Construction | 2025 |
| Plaster R Development Ltd | Real estate | 2025 |
| Plaster R Limited | Construction | 2014 |
| Plastic Box Store Ltd | Administrative & support | 2020 |
| Plastic Box Warehouse Ltd | Wholesale & retail | 2016 |
| Plastic Expert Ltd. | Professional & scientific | 2010 |
| Plastic Tree Studios Ltd | Manufacturing | 2024 |
| Plastic-Id.Com Limited | Administrative & support | 2012 |
| Plastics Express Limited | Wholesale & retail | 2010 |
| Plastivaloire Northampton Limited | Manufacturing | 1997 |
| Platea Aurum Ltd | Health & social care | 2020 |
| Platform Healthcare Ltd | Administrative & support | 2018 |
| Platinum Dent Repair Limited | Wholesale & retail | 2018 |
| Platinum Drive Limited | Transport & logistics | 2026 |
| Platinum Electrics Ltd | Construction | 2021 |
| Platinum Envelope Solutions Limited | Construction | 2019 |
| Platinum Fibre Ltd | Information & communication | 2026 |
| Platinum Hospitality Network Limited | Hospitality | 2017 |
| Platinum Pride K9S Ltd | Administrative & support | 2018 |
| Platinum Property & Sourcing Ltd | Hospitality | 2025 |
| Platinum Rental Properties Limited | Real estate | 2022 |
| Platinum Roofing Limited | Other services | 2012 |
| Platoonix Ltd | Information & communication | 2026 |
| Platzmeter Limited | Transport & logistics | 2024 |
| Playteam Ltd | Administrative & support | 2019 |
| Playwearcollect Ltd | Wholesale & retail | 2025 |
| PLC Proclean Ltd | Administrative & support | 2022 |
| Pleasant Productions Ltd | Information & communication | 2018 |
| Pledge Estates Limited | Real estate | 2023 |
| Plesca Films Ltd | Information & communication | 2019 |
| Plexus Chemicals Limited | Transport & logistics | 1998 |
| PLF Developments Ltd | Hospitality | 2016 |
| PLG Electricals Ltd | Manufacturing | 2007 |
| Plot Nine Property Ltd | Real estate | 2023 |
| Plough Sparsholt Ltd | Hospitality | 2020 |
| Ploutos Limited | Professional & scientific | 2003 |
| PLS Outsourcing Limited | Professional & scientific | 2007 |
| Plugit Studio Ltd | Information & communication | 2026 |
| Pluglabuk Limited | Wholesale & retail | 2025 |
| Plumb-Line Contracting Limited | Construction | 2001 |
| Plumbing MCM Ltd | Construction | 2024 |
| Plumbing DV Ltd | Construction | 2024 |
| Plumbingbits Limited | Wholesale & retail | 2020 |
| Plumbquest Limited | Energy | 2007 |
| Plumleys Bathroom Showroom Limited | Wholesale & retail | 2025 |
| Plumleys Plumbing Merchant Limited | Construction | 2018 |
| Plump Pear Ltd | Hospitality | 2019 |
| Plumsun Ltd | Professional & scientific | 2012 |
| Plunge Ltd | Public administration | 2012 |
| Plus Accountancy Services Limited | Professional & scientific | 2012 |
| Plus One (Recruitment) Ltd | Administrative & support | 2005 |
| Plus Point PR Ltd | Professional & scientific | 2003 |
| Plush Pancakes Limited | Hospitality | 2024 |
| Plushie Blobs Ltd | Manufacturing | 2026 |
| Pluto BV Ltd | Administrative & support | 2025 |
| Pluto Prints Ltd | Wholesale & retail | 2026 |
| Pluto.Bv.Services Ltd | Health & social care | 2010 |
| Plutus Payroll Solutions Ltd | Professional & scientific | 2019 |
| PM & QS Services Ltd | Professional & scientific | 2018 |
| PMA Academy Ltd | Arts & recreation | 2017 |
| PMB Trade Ltd | Wholesale & retail | 2024 |
| PMB Wealth Limited | Financial services | 2025 |
| PMC Buildings Ltd | Construction | 2020 |
| PMD Cleaning Ltd | Administrative & support | 2025 |
| PMK Manning & Sons Limited | Construction | 2013 |
| PMN Developments Ltd | Construction | 2022 |
| PMO Consulting Limited | Professional & scientific | 2022 |
| PMP Construction Limited | Construction | 2015 |
| PMP Wellbeing Hub Ltd | Hospitality | 2022 |
| PMS Care Holdings Ltd | Financial services | 2022 |
| Pn&Cat Ltd | Public administration | 2024 |
| PNB Hire Solutions Ltd | Administrative & support | 2025 |
| Pnbc Services Ltd | Administrative & support | 2015 |
| Pneumox Limited | Health & social care | 2019 |
| PNP Solution Group Limited | Construction | 2016 |
| Pocklingtons (Station Farm) Limited | Real estate | 2024 |
| Pocklingtons Limited | Agriculture & fishing | 2019 |
| Podab Global Limited | Wholesale & retail | 2022 |
| PODIATRY4U Limited | Health & social care | 2019 |
| Podium Infrastructure Design & Consultancy Limited | Information & communication | 2014 |
| Podiumuk Ltd | Education | 2020 |
| Point 2 Point Stonemasonry Limited | Manufacturing | 2023 |
| Point Productions Limited | Information & communication | 1995 |
| Point to Point 2 MAN Delivery Limited | Transport & logistics | 2017 |
| Pointeck Limited | Information & communication | 2010 |
| Poke League Ltd | Wholesale & retail | 2026 |
| Polaris Management Civil Engineering Ltd | Construction | 2021 |
| Poldice Electrical Services Ltd | Construction | 2015 |
| Polflam UK Limited | Manufacturing | 2022 |
| Poli Maxx Limited | Wholesale & retail | 2014 |
| Polish Centre Milton Keynes C.I.C. | Information & communication | 2017 |
| Polish Deli Magda Ltd | Manufacturing | 2006 |
| Polish Food Supplies Limited | Wholesale & retail | 2025 |
| Polish Saturday School in Northampton | Education | 2009 |
| Polish Village Bread Ltd | Manufacturing | 2006 |
| Poll Holdings Limited | Financial services | 2024 |
| Polly Perfect Associates Limited | Administrative & support | 2022 |
| Polskie Lutterworth Ltd | Wholesale & retail | 2024 |
| Polwell Estates Ltd | Real estate | 2025 |
| Polymer Projects Limited | Administrative & support | 2004 |