| Olive Branch Bookkeeping Ltd | Professional & scientific | 2021 |
| Oliver Steel Limited | Other services | 2020 |
| Ollo Partnerships Ltd | Information & communication | 2025 |
| Olobob Top Ltd | Information & communication | 2018 |
| ON Purpose Consulting Limited | Health & social care | 2008 |
| One Bell Lane Investments Limited | Financial services | 2024 |
| One Bell Lane Property LLP | | 2024 |
| One Wild Group CIC | Education | 2017 |
| Oniorthopaedics Limited | Professional & scientific | 2020 |
| OOF Mortgages Ltd | Financial services | 2025 |
| Open Bakery Ltd | Wholesale & retail | 2020 |
| Open Routes Research Ltd | Professional & scientific | 2025 |
| Open Space Associates Limited | Professional & scientific | 2015 |
| Operate GTM Limited | Professional & scientific | 2026 |
| Opfor Security Services Ltd | Financial services | 2021 |
| Orange Badge Mobility Services Limited | Wholesale & retail | 2012 |
| Organic Property Company Limited | Real estate | 2002 |
| Osprey Clarke Interim Executives LLP | | 2014 |
| Osprey Clarke International & Emerging Markets LLP | | 2016 |
| Otherfield Limited | Information & communication | 2020 |
| Ouse Dragon Productions CIC | Arts & recreation | 2025 |
| Ouse Valley Energy Services Company C.I.C. | Administrative & support | 2007 |
| Ouse Valley Solar Farm CIC | Energy | 2021 |
| OUT of Sync Limited | Information & communication | 2015 |
| Oversound Ltd | Information & communication | 2019 |
| Overton Partners Ltd | Financial services | 2013 |
| Owen Project Management & Consulting Limited | Professional & scientific | 2007 |
| OWL Taxis Ltd | Transport & logistics | 2019 |
| OWL Wellbeing Limited | Other services | 2023 |
| Own Your Light Ltd | Wholesale & retail | 2025 |
| P Gandy Built Environment Advisory Limited | Professional & scientific | 2025 |
| P J H Automotive Limited | Wholesale & retail | 2005 |
| P. K. Griffin Property Company Limited | Real estate | 1968 |
| P1BGB Consulting Ltd | Professional & scientific | 2026 |
| Padà Africa Limited | Hospitality | 2023 |
| Pages PS Ltd | Hospitality | 2023 |
| Painted Doll Productions Limited | Arts & recreation | 2013 |
| Palma Studio Limited | Information & communication | 2015 |
| Palmers Wealth Management Ltd | Financial services | 2017 |
| Pamela Kent Consulting Limited | Arts & recreation | 2022 |
| Pandion Research LLP | | 2010 |
| Panorea Films Limited | Information & communication | 2025 |
| Papertrail Promotions Ltd | Professional & scientific | 2025 |
| Pargeter Bodyworks Ltd | Health & social care | 2018 |
| Parker-Greig Ltd | Real estate | 2012 |
| Parosity Ltd | Administrative & support | 2026 |
| Partimber Ltd | Manufacturing | 2024 |
| Partnerships in Practice Limited | Professional & scientific | 2014 |
| Past Life Films Ltd | Information & communication | 2025 |
| Patrick Bower Ltd | Information & communication | 2023 |
| Pats in the PUB Limited | Hospitality | 2023 |
| Paul Moulton Consulting Ltd | Information & communication | 2019 |
| PBI Audio Visual Limited | Professional & scientific | 2003 |
| PCB Electrical Solutions Ltd | Construction | 2017 |
| Peacehaven Builders Ltd | Construction | 2016 |
| Peacehaven Golf Club Limited | Arts & recreation | 2007 |
| Peacharno Consulting Limited | Professional & scientific | 2011 |
| Pearl Whirl Productions Ltd | Arts & recreation | 2025 |
| Pedersen Projects Limited | Administrative & support | 2008 |
| Peer Accounting Ltd. | Professional & scientific | 2020 |
| Pegasus Builders Limited | Construction | 2006 |
| Pelham Mews Management Ltd | Real estate | 2005 |
| Pelham Productions Limited | Information & communication | 2016 |
| Pellbrook Place Management Company Limited | Households | 1997 |
| Pells Consultancy Limited | Professional & scientific | 2018 |
| Pells Pool Community Association | Arts & recreation | 2001 |
| Pelorus Ltd | Professional & scientific | 2010 |
| Pemba Group Limited | Real estate | 2024 |
| Pendy Limited | Financial services | 2015 |
| Penn Penn Limited | Administrative & support | 2013 |
| Penrose Film Productions Limited | Arts & recreation | 2017 |
| People in Commons C.I.C. | Professional & scientific | 2024 |
| People's Park for Nature C.I.C. | Arts & recreation | 2024 |
| Percivon Technologies Inc. | | 2024 |
| Performance Fire Protection Limited | Administrative & support | 1996 |
| Performr Limited | Information & communication | 2013 |
| Perkin Shield Ltd | Households | 2026 |
| Pestfield Limited | Professional & scientific | 2009 |
| Pestopesto Ltd | Wholesale & retail | 2025 |
| Pet-Id Microchips Ltd | Professional & scientific | 2012 |
| Peter Gordon Anderson Medical Services Ltd | Health & social care | 2019 |
| Peter Lambert Production Services Limited | Arts & recreation | 2003 |
| Petr & Sons Ltd | Construction | 2026 |
| Petroscape Limited | Professional & scientific | 2019 |
| Pettrac Limited | Extraterritorial | 1991 |
| Pharma Co. Logic Limited | Professional & scientific | 2001 |
| Pharmacie Coffee Roasters Ltd | Wholesale & retail | 2015 |
| Phase Consultants Limited | Administrative & support | 2006 |
| Philcox(Bros.)Limited | Construction | 1962 |
| Phix Decorating and Spraying Limited | Construction | 2026 |
| Phonicsplay Limited | Education | 2010 |
| Photopro Ltd | Arts & recreation | 2010 |
| PHYSIOWORKS87 Ltd | Health & social care | 2016 |
| Pieces of Eight Pets Limited | Wholesale & retail | 1995 |
| Pieces Styles Limited | Information & communication | 2005 |
| Pinnacle Esher Limited | Construction | 2016 |
| Pinnacle Vision Consulting Ltd | Professional & scientific | 2014 |
| Pinwell Road Estate Management Company Limited | Real estate | 2002 |
| Pinwell Road Flats Management Company Limited | Households | 2002 |
| PIP Services (Southern) Limited | Hospitality | 1999 |