| Nusmark Ltd | Information & communication | 2024 |
| NWP Digital Ltd | Construction | 2017 |
| Nysa Property Ltd | Real estate | 2018 |
| Oak Tree Fortune Limited | Wholesale & retail | 2022 |
| Oakenshaw Court Residents Association(Number 2)LIMITED | Households | 1961 |
| Oasis Rooftops Limited | Administrative & support | 2024 |
| Oatley Coffee Ltd | Manufacturing | 2024 |
| OB Design Studio Ltd | Professional & scientific | 2026 |
| OCEAN1 Services Limited | Real estate | 2023 |
| ODD Pumpkin Studio Ltd | Arts & recreation | 2018 |
| OF Oakley Ltd | Information & communication | 2023 |
| Ojasmed Ltd | Administrative & support | 2025 |
| OKP Productions Limited | Information & communication | 2012 |
| Old Boots Enterprises Ltd | Information & communication | 2021 |
| OLJ Services Ltd | Professional & scientific | 2018 |
| Omigration Limited | Extraterritorial | 2021 |
| Omtel Consulting Limited | Professional & scientific | 2012 |
| ON Site Events Limited | Administrative & support | 2004 |
| One Famalay Ltd | Arts & recreation | 2019 |
| Onesource PM Solutions Ltd | Administrative & support | 2025 |
| Online Darts Live League Limited | Arts & recreation | 2021 |
| Onlyconnect Limited | Professional & scientific | 2002 |
| Onside Football Coaching Ltd | Arts & recreation | 2016 |
| Onyx International Investments Ltd | Real estate | 2015 |
| Open Commissioning Ltd | Professional & scientific | 2023 |
| Open Door Psychology CIC | Health & social care | 2024 |
| Ophelia Limited | Information & communication | 2000 |
| Opie House (RTE) Management Limited | Real estate | 2003 |
| Opiniano Design Consultancy Limited | Professional & scientific | 2011 |
| Optima Outsourcing Solutions Ltd | Extraterritorial | 2008 |
| Optima Site Solutions Limited | Administrative & support | 2001 |
| Opulent Autohaus Limited | Wholesale & retail | 2025 |
| Orange Crocodile Ltd | Extraterritorial | 2016 |
| Orbital Insurance Services Limited | Professional & scientific | 1988 |
| Org-Worx Ltd | Professional & scientific | 2019 |
| Orma Ltd | Arts & recreation | 2020 |
| Orsecho Investments UK Limited | Real estate | 2018 |
| Osmunda Court RTM Company Limited | Households | 2013 |
| OSS Group Holdings Limited | Financial services | 2021 |
| Otherlevels Limited | Information & communication | 2013 |
| Otomatiq Ltd | Wholesale & retail | 2022 |
| Outback Cafe Ltd | Hospitality | 2019 |
| Outdoor SLT Ltd | Health & social care | 2026 |
| Over Land & Sea Limited | Transport & logistics | 2008 |
| Ovid Limited | Wholesale & retail | 2013 |
| OX Squared Healthcare Ltd | Health & social care | 2025 |
| Oyster Island Films Limited | Professional & scientific | 2009 |
| OZ Club Ltd | Professional & scientific | 2018 |
| P D Stonier Limited | Professional & scientific | 2013 |
| P Linton Limited | Wholesale & retail | 2026 |
| P&Pg Estates Ltd | Households | 2024 |
| P&Pg Properties Ltd | Households | 2024 |
| P&W Property Holdings Limited | Real estate | 2019 |
| P23C Events Ltd | Administrative & support | 2025 |
| P365 Limited | Other services | 2017 |
| Pain and Wellbeing Ltd | Health & social care | 2020 |
| Palestrina London Limited | Wholesale & retail | 2016 |
| Palmerston Court (Surbiton) NO. 2 Residents Association Limited | Households | 1968 |
| Pamard Property Investments Ltd | Real estate | 2016 |
| Pandion Management Ltd | Real estate | 2018 |
| Panorama of the Thames Limited | Information & communication | 2013 |
| Papaya Jewellery Ltd | Manufacturing | 2023 |
| Parniyan SLR Ltd | Professional & scientific | 2020 |
| Partell Properties Ltd | Extraterritorial | 2018 |
| Parvis Magna Productions Ltd | Information & communication | 2020 |
| Passive Real Estates Ltd | Real estate | 2020 |
| Patenslow Investments Ltd | Real estate | 2019 |
| Paul Property Consultants Limited | Real estate | 2016 |
| Paws Academy Daycare Ltd | Other services | 2021 |
| Paxton Personnel Ltd | Administrative & support | 2023 |
| Paypath Limited | Real estate | 2002 |
| Paytill Ltd | Financial services | 2024 |
| PB Company Secretary Limited | Administrative & support | 2005 |
| PBS Building and Decorating Services Ltd | Construction | 2010 |
| Peach Hair & Beauty Ltd | Other services | 2025 |
| Peak Property Options Ltd | Real estate | 2016 |
| Pemberton House Limited | Real estate | 1999 |
| Pentland Gardens (Wandsworth) Management Company Limited | Hospitality | 1996 |
| PEP & Bear Ltd. | Other services | 2019 |
| Pepa Cleaning Ltd | Administrative & support | 2026 |
| Performance Research Centre Limited | Professional & scientific | 2004 |
| Period Electricals Limited | Information & communication | 2021 |
| Periwinkle Developments Limited | Real estate | 1988 |
| Persuasive Properties Ltd | Extraterritorial | 2018 |
| PGK Estates Ltd | Real estate | 2026 |
| Pharos Marine Automatic Power Limited | Mining & quarrying | 2008 |
| Pharos Marine Holdings Limited | Financial services | 2025 |
| Phatty Boom Boom Limited | Wholesale & retail | 2024 |
| Piazza Firenze Limited | Hospitality | 2006 |
| Pilot Agencies Limited | Professional & scientific | 1990 |
| Pink Fatale Limited | Wholesale & retail | 2021 |
| Pink Leaves Ltd | Wholesale & retail | 2024 |
| Pinnacle Global Solutions Limited | Administrative & support | 2026 |
| Pins & Needles Club Ltd | Education | 2020 |
| Pintells Pharma Consulting Ltd | Professional & scientific | 2019 |
| Pirano Energy UK Limited | Professional & scientific | 2019 |
| Pishter Limited | Professional & scientific | 2003 |
| Pitchperfectstats Ltd | Arts & recreation | 2024 |
| Pixelbrink Software Limited | Information & communication | 2024 |
| PJ Asia Ltd | Real estate | 2017 |