| Norcott Management Company Limited | Real estate | 1998 |
| North Orbital Road RTM Company Limited | Other services | 2003 |
| Notorious Films Limited | Information & communication | 2004 |
| Noustelo Ltd | Professional & scientific | 2025 |
| Novi Most International | Health & social care | 1995 |
| O Construction Limited | Construction | 2002 |
| Oakley Court (Gerrards Cross) Management Limited | Households | 2016 |
| Obsido Property Ltd | Real estate | 2022 |
| Odette Lingerie Ltd | Wholesale & retail | 2015 |
| ODO Ltd | Information & communication | 2023 |
| OK Farms Limited | Agriculture & fishing | 2011 |
| Oliver James London Ltd | Wholesale & retail | 2017 |
| Omgl Ltd | Information & communication | 2022 |
| Operose Health (Group) Limited | Professional & scientific | 2006 |
| Operose Health (Group) UK Limited | Health & social care | 2005 |
| Operose Health Corporate Management Limited | Professional & scientific | 2011 |
| Operose Health Limited | Health & social care | 2016 |
| Orchard Court (60WR) Management Limited | Households | 2004 |
| Orchard Court Greenway Management Limited | Households | 2007 |
| Orchard Mews (Great Missenden) Management Company Limited | Real estate | 2021 |
| Oswell International S.A. Limited | Extraterritorial | 1999 |
| Over Hampden Ltd | Professional & scientific | 2015 |
| Oxmoor Farm Events Limited | Hospitality | 2024 |
| Oxus GIN Ltd. | Wholesale & retail | 2016 |
| Oziada Multimedia Limited | Information & communication | 2021 |
| P.B.Clinical Research Limited | Professional & scientific | 2011 |
| P.G.C. Refurbishment Limited | Construction | 2004 |
| Pagalavan Ltd | Wholesale & retail | 2025 |
| Parkvalley Limited | Households | 1982 |
| Pathila Tandoori Ltd | Hospitality | 2023 |
| PB Woodcraft Ltd | Manufacturing | 2020 |
| PDR Financial Consultancy Ltd | Professional & scientific | 2014 |
| Pear Tree Close Management Limited | Households | 2007 |
| Pearcroft Developments 1 Limited | Construction | 2022 |
| Pearcroft Developments 2 Limited | Real estate | 2022 |
| Pearcroft Developments 3 Limited | Construction | 2022 |
| Pearcroft Developments 5 Ltd | Construction | 2022 |
| Pearcroft Developments 6 Limited | Real estate | 2025 |
| Pearcroft Developments 7 Limited | Construction | 2025 |
| Pearcroft Developments Maidenhead Ltd | Construction | 2024 |
| Pearcroft Fourells Ltd | Construction | 2025 |
| Pearcroft Group Limited | Construction | 2024 |
| Pearcroft Homes Ltd | Construction | 2022 |
| Pearcroft Land Ltd | Real estate | 2025 |
| Pearcroft Plumbing Limited | Construction | 2024 |
| Pearcroft Solar and Electrical Ltd | Construction | 2024 |
| Penn (Residents) Limited | Households | 1984 |
| Penn Haven (Freehold) Limited | Households | 1999 |
| Penn Haven (Management) Limited | Households | 1987 |
| Pentlands (Management) Company Limited(The) | Households | 1987 |
| Perks Lane Flats (Management) Limited | Households | 1984 |
| Peters Research Limited | Information & communication | 1997 |
| Phoenix Primary Care (South) Limited | Health & social care | 2010 |
| Phoenix Primary Care Limited | Health & social care | 2007 |
| Photography by US Ltd | Professional & scientific | 2013 |
| Physega Ltd | Professional & scientific | 2010 |
| Piccadilly Pictures Ltd | Financial services | 2018 |
| Pink Beverages Limited | Wholesale & retail | 2026 |
| PIP Leaver Consultancy Ltd | Professional & scientific | 2026 |
| Pitcomp Properties Limited | Real estate | 2008 |
| PKF Business Solutions Ltd | Professional & scientific | 2020 |
| Planet 3 Limited | Professional & scientific | 2011 |
| Plough Group Ltd | Real estate | 2023 |
| PMI Consult Limited | Professional & scientific | 2002 |
| PMI Global Holdings Limited | Professional & scientific | 2007 |
| POD Lifestyle Ltd | Construction | 2022 |
| Polar Engineering Supplies Limited | Manufacturing | 2008 |
| Polgrain Consulting Ltd | Real estate | 2019 |
| Popcorn PR Limited | Professional & scientific | 2012 |
| Posh Hippy Ltd | Administrative & support | 2025 |
| Potters Close Residents' Association (Prestwood) Limited | Households | 1991 |
| Powerdev Limited | Information & communication | 2000 |
| Prasel Limited | Information & communication | 2016 |
| Precision Physiotherapy Limited | Health & social care | 2011 |
| Prestige Worldwide Services & Management Ltd | Construction | 2020 |
| Prestwood Park House Limited | Households | 1988 |
| Primary Care Partners Limited | Health & social care | 2019 |
| Prime Location Property Limited | Real estate | 2025 |
| Prior Construction Services Ltd | Construction | 2018 |
| Professional Interim Services Ltd | Professional & scientific | 2013 |
| Profinance Consultancy Limited | Professional & scientific | 2010 |
| Project Hope, United Kingdom | Health & social care | 1994 |
| Project Keystone Limited | Real estate | 2026 |
| Prosperite MM1 Limited | Mining & quarrying | 2022 |
| Provoke Furniture Design Ltd | Manufacturing | 2025 |
| PS Hvac Limited | Energy | 2017 |
| Pulse OS Ltd | Information & communication | 2025 |
| Pure Development Management Limited | Construction | 2020 |
| Quantum 13 Limited | Construction | 2025 |
| Quantum 5000 Limited | Professional & scientific | 2014 |
| Rage Design Limited | Professional & scientific | 1998 |
| Ranco Controls Limited | Professional & scientific | 1961 |
| Raven Chapman Limited | Arts & recreation | 2021 |
| Ravished Retro Ltd | Wholesale & retail | 2024 |
| RCS Plumbing Ltd | Construction | 2020 |
| React Gutter Clearance Ltd | Construction | 2021 |
| Readytown Property Management Limited | Households | 1988 |
| Reborn Bakelite Limited | Wholesale & retail | 2017 |
| Red Tail Kite Landscapes & Construction Limited | Administrative & support | 2017 |
| Reel Fearz Ltd | Information & communication | 2021 |