| Nurture Property Ltd | Real estate | 2020 |
| Nutfield Day Nursery Limited | Other services | 2008 |
| Nviz Films Limited | Information & communication | 2025 |
| Nxdata Limited | Information & communication | 2024 |
| O L C Plumbing and Heating Limited | Construction | 2024 |
| Oak Tree Education Consultancy Limited | Education | 2016 |
| Oatlands RTM Company Limited | Households | 2024 |
| Occam's Envoy Limited | Information & communication | 2013 |
| Ocean Bloo Ltd | Construction | 2007 |
| Odenco Ltd | Information & communication | 2014 |
| Odiosis Limited | Financial services | 2019 |
| Ogmore Property Ltd | Real estate | 2022 |
| OHM Marketing Ltd | Information & communication | 2025 |
| OIL Free Lubricants Ltd | Wholesale & retail | 2022 |
| OJD Homes Ltd | Real estate | 2020 |
| OLA Online Ltd | Wholesale & retail | 2023 |
| Old Dairy Mews (Horse Hill) Management Company Limited | Households | 2025 |
| Old Mill Tree Care Ltd | Administrative & support | 2024 |
| Oldmeadow Renovations Ltd | Construction | 2019 |
| Olive House Mediation Ltd | Professional & scientific | 2021 |
| Olly & Co. Collective Ltd | Financial services | 2025 |
| Olly Burrow Design Limited | Professional & scientific | 2025 |
| Olympia Investments Limited | Professional & scientific | 2005 |
| ON ALL Floors Ltd | Construction | 2012 |
| ON Ice Ltd | Wholesale & retail | 2011 |
| One Oak Garden Design Ltd | Administrative & support | 2018 |
| One Stop Lawn Care Ltd | Administrative & support | 2022 |
| Onirem Solutions Ltd | Information & communication | 2024 |
| Onyx Highways Ltd | Construction | 2025 |
| Ophiussa Ltd | Professional & scientific | 2019 |
| Ophtiq Ltd | Information & communication | 2026 |
| Optimumlex Services Limited | Professional & scientific | 2025 |
| Optimus Heating & Plumbing Ltd | Construction | 2021 |
| Optimus Heating Ltd | Construction | 2021 |
| Orbital Haulage Ltd | Transport & logistics | 2025 |
| Orchid Property Maintenance Limited | Extraterritorial | 2017 |
| Ordex Construction Limited | Construction | 2014 |
| Orivio Ltd | Manufacturing | 2026 |
| Orthopaedic Technology Ort-Medical Ltd | Health & social care | 2015 |
| Orthopaedic Technology Ort-Medical Vita Ltd | Health & social care | 2024 |
| Orthotic Prosthetic Supplies Ltd | Manufacturing | 2024 |
| Outdoor Works London Ltd | Construction | 2017 |
| Outsider Pictures Limited | Information & communication | 2025 |
| Ovation Productions Limited | Arts & recreation | 2020 |
| Overhouse Limited | Administrative & support | 2017 |
| Oxford Microtech Systems Limited | Information & communication | 2010 |
| Oxsyst IT Solutions Limited | Real estate | 2007 |
| Oxted Company Assets Ltd | Professional & scientific | 2014 |
| Oxted Group Limited | Professional & scientific | 2006 |
| Oxted Trimming Company Limited | Administrative & support | 1997 |
| Oxyvias Limited | Manufacturing | 2025 |
| Ozkutan and Esparon Limited | Real estate | 2010 |
| P D Motor Services Ltd | Wholesale & retail | 2018 |
| P SET Ltd | Manufacturing | 2025 |
| P Stubbs Consultancy Limited | Administrative & support | 2007 |
| PAA Vehicle Sales Ltd | Wholesale & retail | 2010 |
| PAD Holding Group Ltd | Professional & scientific | 2025 |
| Pagey’S Pet Care Ltd | Other services | 2025 |
| Painty Pots Ltd | Arts & recreation | 2025 |
| Palindrome Publishing Ltd | Information & communication | 2020 |
| Panelistclo Ltd | Wholesale & retail | 2025 |
| Panther Car Club Limited(The) | Other services | 1982 |
| Paper Rainbow Ltd. | Professional & scientific | 2015 |
| Papilio Aesthetics Ltd | Health & social care | 2022 |
| Para Actuarial Limited | Financial services | 2020 |
| Paracise Ltd | Arts & recreation | 2017 |
| Paradise Organics London Ltd | Wholesale & retail | 2015 |
| Paragon (PGN) Ltd | Information & communication | 2014 |
| Paramount Waste Extraction Limited | Manufacturing | 1999 |
| Pardy Bespoke Ltd | Manufacturing | 2022 |
| Parkhurst Residents Association Limited | Households | 1985 |
| Pathogen Reduction Solutions Limited | Manufacturing | 2020 |
| Patrick Bettesworth Limited | Construction | 2007 |
| Paul Kenny Heating and Plumbing Limited | Construction | 2017 |
| Paul Knowles Special Effects Limited | Information & communication | 2015 |
| Paul Moore Consulting Engineers Limited | Professional & scientific | 2008 |
| Pausedeal Limited | Households | 1998 |
| Paycloudlg Limited | Information & communication | 2023 |
| PC Mailroom Consultancy Limited | Administrative & support | 2018 |
| Pdms Developments Ltd | Real estate | 2025 |
| Peak 15 Business Services Ltd | Administrative & support | 2016 |
| Peak 15 Ltd | Health & social care | 2007 |
| Peak 15 Property Services Ltd | Construction | 2016 |
| Pearlbridge Network Ltd | Transport & logistics | 2026 |
| Peartree Cottage Estates Limited | Real estate | 1998 |
| Pegaso Building Contractors Ltd | Construction | 2014 |
| Pelham House Limited | Real estate | 2016 |
| Pendrill AV Limited | Construction | 2022 |
| Pennywell Healthcare Limited | Health & social care | 2018 |
| Pennywell Medical Limited | Health & social care | 2025 |
| Percy Harper Limited | Information & communication | 2016 |
| Periketi Investments Limited | Real estate | 2024 |
| Perilla Clothing Limited | Wholesale & retail | 2025 |
| Petal & Feast Ltd | Hospitality | 2013 |
| Pete Allibone Limited | Information & communication | 2007 |
| Peter Felstead Consulting Ltd | Arts & recreation | 2022 |
| Petrovend Limited | Real estate | 1986 |
| Peyza Ltd | Manufacturing | 2026 |
| PF Project Management Limited | Construction | 2016 |
| PGS Electrical Services Ltd | Construction | 2026 |