| Oepus Capital Ltd | Professional & scientific | 2025 |
| Official UK Trade Ltd | Wholesale & retail | 2017 |
| Ojjcy Ltd | Information & communication | 2026 |
| Okapi Creations Ltd | Information & communication | 2023 |
| OKE Property Limited | Real estate | 2022 |
| Oklm Recycling Technology Limited | Extraterritorial | 2011 |
| Old Acorns Limited | Real estate | 2017 |
| Old Lodge Court Freeholders Limited | Households | 2002 |
| Old Lodge Property Solutions Limited | Real estate | 2022 |
| Old Thorns Limited | Professional & scientific | 2012 |
| Olooc Ltd | Health & social care | 2026 |
| Omhg Logistics Limited | Transport & logistics | 2026 |
| OMI Foods Limited | Hospitality | 2025 |
| Omkara Investments Ltd | Real estate | 2019 |
| ON Path Consultancy Ltd | Professional & scientific | 2024 |
| One Hundred Limited | Information & communication | 2008 |
| ONE08 Tech Ltd | Information & communication | 2025 |
| ONE10SECURITY Limited | Administrative & support | 2025 |
| Oneworld Leisure Limited | Administrative & support | 1999 |
| Onyx Bakery Limited | Wholesale & retail | 2024 |
| Openmere Limited | Households | 1986 |
| Optech Media Ltd | Information & communication | 2021 |
| Oracle Records Ltd | Information & communication | 2015 |
| Orange Holdco Ltd | Health & social care | 2022 |
| Organic Integrated Farms UK Ltd | Agriculture & fishing | 2021 |
| Orhan Zeki Ltd | Wholesale & retail | 2025 |
| Orion Electrical Developments Ltd | Construction | 2025 |
| Ortho-Legal Experts Ltd | Other services | 2012 |
| Osilaja Financial Consulting Limited | Financial services | 2025 |
| OSR Fitness & Wellbeing Ltd | Arts & recreation | 2017 |
| OSR Online Solutions Limited | Arts & recreation | 2020 |
| Overhill Road Residents Company Limited | Households | 2018 |
| OVY Services Limited | Transport & logistics | 2023 |
| P & B London Ltd | Financial services | 2022 |
| P&B New Homes Ltd | Construction | 2007 |
| P&H Nicholas Ltd | Real estate | 2020 |
| PA Architects Limited | Professional & scientific | 2004 |
| Paddington Associates Limited | Information & communication | 2011 |
| Pakistan Foods Limited | Wholesale & retail | 2021 |
| Palmerston Limited | Other services | 2020 |
| Palmerston Nominees Limited | Professional & scientific | 1995 |
| Palmerston Probate Limited | Other services | 2019 |
| Palmerston Registrars Limited | Professional & scientific | 1988 |
| Palmerston Secretaries Limited | Professional & scientific | 1992 |
| Pamba Professional Services Ltd | Professional & scientific | 2012 |
| Panimar Properties Limited | Real estate | 2023 |
| Papa & Ishi Ltd | Real estate | 2020 |
| Paper Jones Limited | Information & communication | 2025 |
| Paperbacknow Limited | Information & communication | 2011 |
| Pappabee Limited | Professional & scientific | 2018 |
| Pappabee Solutions Limited | Information & communication | 2026 |
| Param Limited | Information & communication | 2011 |
| Param Property Limited | Real estate | 2026 |
| PART333 Limited | Wholesale & retail | 2025 |
| Pasha Immigration Consultancy Ltd | Professional & scientific | 2011 |
| Patel Squared Limited | Real estate | 2020 |
| Patientflow Systems Limited | Information & communication | 2025 |
| Paul Maximillian Ltd | Construction | 2024 |
| Paulinbef Limited | Health & social care | 2022 |
| Payanalytics Holdings Ltd. | Financial services | 2023 |
| Payment Advisory Ltd | Information & communication | 2026 |
| PBC Consultants Limited | Information & communication | 2013 |
| PBC Properties Limited | Real estate | 2016 |
| Pbtc Social Limited | Hospitality | 2017 |
| PDO Change Management Limited | Professional & scientific | 2018 |
| Peace in Mind Counselling Ltd | Health & social care | 2023 |
| Peachtree Capital Limited | Financial services | 2022 |
| Peaklawn Limited | Other services | 2006 |
| Pearl River Ltd | Wholesale & retail | 2023 |
| Penny Care Solutions Ltd | Health & social care | 2023 |
| Penny Worrall Limited | Manufacturing | 2021 |
| Penwortham Songs Limited | Information & communication | 2014 |
| Pepa Trading Co. Limited | Wholesale & retail | 2022 |
| Pepper HUT Limited | Manufacturing | 2025 |
| Pepperpot Digital Limited | Administrative & support | 2011 |
| Perfectress Limited | Administrative & support | 2010 |
| Pergamos Consulting Ltd | Professional & scientific | 2025 |
| Pergamos Ltd | Construction | 2020 |
| Permacare Limited | Health & social care | 2023 |
| Perola DO Atlantico Ltd | Hospitality | 2019 |
| Perserve Ltd | Professional & scientific | 2008 |
| PHA Properties Limited | Health & social care | 2014 |
| Pharmaoptics Limited | Wholesale & retail | 2023 |
| PHM Consultancy UK Limited | Professional & scientific | 2019 |
| Pierhead Lock Freehold Limited | Extraterritorial | 2021 |
| Pilkesh Limited | Financial services | 2022 |
| Pinnacle Prime Properties Ltd | Real estate | 2025 |
| Piris Property Limited | Real estate | 2020 |
| Pirsa Limited | Professional & scientific | 2024 |
| PKW Trade Ltd | Wholesale & retail | 2022 |
| Plank and Hammer Ltd | Construction | 2025 |
| Plann Accommodation Limited | Real estate | 2010 |
| Planning HOA Limited | Professional & scientific | 2022 |
| Platinum DRY Cleaners Purley Ltd | Administrative & support | 2026 |
| Play & Thrive Club Ltd | Health & social care | 2026 |
| Playhouse Partnership Ltd | Professional & scientific | 2024 |
| Playmaker Corporation Ltd | Information & communication | 2025 |
| PMA SK Property Limited | Real estate | 2025 |
| Podesta Limited | Financial services | 2026 |
| Polished Manners Limited | Other services | 2015 |