| Oulton Enterprises Ltd | Hospitality | 2021 |
| Ouseside Contracts Limited | Construction | 2016 |
| Outdoor Adventure Girls Ltd | Administrative & support | 2022 |
| Outlead Limited | Professional & scientific | 2025 |
| Oxbridge Scholars Ltd | Education | 2025 |
| Oxdrive Limited | Manufacturing | 2021 |
| Oxford Sport & Traditional Martial Arts Schools Limited | Education | 2013 |
| Oxford Travelling Books Limited | Wholesale & retail | 2014 |
| Oysta Opportunities and Advisory Services Ltd | Professional & scientific | 2024 |
| P W Landscapes Ltd | Administrative & support | 2020 |
| P&E Roofing Limited | Construction | 2019 |
| PA Digital Future Ltd | Wholesale & retail | 2025 |
| Pace Commerce Ltd | Wholesale & retail | 2019 |
| Paice Flooring Limited | Construction | 2011 |
| Paint Logistics Ltd | Wholesale & retail | 2014 |
| Pallalux Ltd | Professional & scientific | 2026 |
| Palmer Defence Ltd | Professional & scientific | 2025 |
| Pams Event Services Ltd | Administrative & support | 1995 |
| Pancake Consulting Limited | Professional & scientific | 2017 |
| Papawhiskey Limited | Information & communication | 2011 |
| Park Architectural Limited | Manufacturing | 2011 |
| Park Business Group Limited | Financial services | 2011 |
| Park Maintenance Limited | Manufacturing | 2011 |
| Parker Kitchens Limited | Manufacturing | 2012 |
| Partner Electronics Limited | Information & communication | 2007 |
| Partnership Mortgage Group Ltd | Financial services | 2022 |
| Pass Construction Limited | Construction | 2021 |
| Pathena Limited | Arts & recreation | 2023 |
| Pathfinder Counselling Ltd. | Administrative & support | 2016 |
| Patient Property Services Ltd. | Construction | 2013 |
| Patternise Laser Ltd | Manufacturing | 2022 |
| Pattishall Events CIC | Other services | 2022 |
| Paul Harris Project Solutions Ltd | Professional & scientific | 2025 |
| Paul's Pury Services Ltd | Construction | 2009 |
| Paula Steven's Ltd | Other services | 2002 |
| Pawfect Rentals Ltd | Administrative & support | 2025 |
| Paxton Holdings UK Ltd | Real estate | 2026 |
| Paynes Nurseries (Towcester) Limited | Wholesale & retail | 1945 |
| Pb&J Limited | Other services | 2022 |
| PBC Brick Cutting and JET Washing Ltd | Construction | 2026 |
| PDM84 Ltd | Professional & scientific | 2025 |
| PDQ Contract Flooring Limited | Construction | 2004 |
| PDR Roofing Services Limited | Construction | 2017 |
| Peace Branch Project Support Ltd | Information & communication | 2025 |
| Peach-Comms Ltd | Other services | 2024 |
| Peaky Blinders Mobile Mechanic Ltd | Professional & scientific | 2022 |
| Pebble Labs Limited | Information & communication | 2026 |
| Peck Investments Limited | Real estate | 2018 |
| Pedro Figueiredo Ltd | Information & communication | 2025 |
| Peggottys Bar & Restaurant Ltd | Hospitality | 2026 |
| Penn Farming Ltd | Real estate | 2021 |
| Penola Group Ltd | Real estate | 2026 |
| Penola Limited | Construction | 2023 |
| Pentagram Technical Services Limited | Information & communication | 2014 |
| People Access Ltd | Information & communication | 2011 |
| Pequod Holdings Ltd | Hospitality | 2016 |
| Perfect Performance Investments Ltd | Professional & scientific | 2025 |
| Perhow 99 Limited | Wholesale & retail | 1992 |
| Pericom Limited | Information & communication | 1990 |
| Perrigo Marketing Limited | Wholesale & retail | 2014 |
| Peters Agricultural & Groundworks Ltd | Agriculture & fishing | 2025 |
| Petherton Consultancy Limited | Professional & scientific | 2018 |
| Petone Holdings Limited | Financial services | 2023 |
| Pettifer Management Ltd | Transport & logistics | 2026 |
| Pewter UK Apps Limited | Information & communication | 2024 |
| PFS Manufacturing Limited | Professional & scientific | 2019 |
| Phipps & Co Textile Products Limited | Wholesale & retail | 2005 |
| Phipps & Family Limited | Professional & scientific | 2022 |
| Pianotechservices Limited | Professional & scientific | 2017 |
| Pictop Ltd | Professional & scientific | 2014 |
| Piece by Piece Books Ltd | Professional & scientific | 2019 |
| Pieris Holdings Ltd | Administrative & support | 2017 |
| PIK Pubs Limited | Hospitality | 2024 |
| Pilsbury Motorsport Limited | Wholesale & retail | 2025 |
| Pineapple Plant Ltd | Administrative & support | 2017 |
| Pink COW Events Ltd | Hospitality | 2026 |
| Pink COW Marketing Ltd | Professional & scientific | 2020 |
| Pinnacle Alternative Drive Solutions Ltd | Professional & scientific | 2010 |
| Pinnacle Property Development and Construction Ltd | Construction | 2014 |
| Pivot Services UK Ltd | Professional & scientific | 2025 |
| Pixode Games Limited | Information & communication | 2016 |
| Platform Thirteen Ltd | Professional & scientific | 2017 |
| Players Properties and Homes Ltd | Real estate | 2023 |
| Players Properties LLP | | 2018 |
| Plexus Communications Ltd | Professional & scientific | 2015 |
| Pllm Ltd | Arts & recreation | 2025 |
| Plugin Design Limited | Professional & scientific | 2005 |
| Plumtree Prints Ltd | Manufacturing | 2025 |
| PN Business Analysis Limited | Public administration | 2016 |
| POD Consulting Limited | Professional & scientific | 2017 |
| Point Zero Zero One Limited | Manufacturing | 2017 |
| Polarity Films (Onyx) Ltd | Information & communication | 2024 |
| Polarity Films Ltd | Information & communication | 2012 |
| Pollygene Ltd | Administrative & support | 2017 |
| Polyfony Limited | Hospitality | 2010 |
| Pomfret Management Limited | Construction | 2021 |
| Pomfret Partners LLP | | 2018 |
| Port House Limited | Hospitality | 2022 |
| Portland Group Investments Limited | Real estate | 2020 |
| Portland Lombard Electrical Services Ltd | Administrative & support | 2017 |