| Online Profile Management Limited | Information & communication | 2025 |
| Online Wealth Enterprise Ltd | Wholesale & retail | 2010 |
| Onsite Support Holdings Limited | Professional & scientific | 2011 |
| Onsite Support Limited | Wholesale & retail | 1980 |
| Ontime Cars Gatwick Ltd | Transport & logistics | 2020 |
| Oostalea Holdings Limited | Real estate | 2017 |
| Opadpro Ltd | Professional & scientific | 2025 |
| Opel Transport & Trading Company Limited | Extraterritorial | 1973 |
| Openhaus Kitchens Limited | Wholesale & retail | 2015 |
| Opensource Cafe Ltd | Manufacturing | 2018 |
| Optima Systems Holdings Limited | Information & communication | 2021 |
| Optima Systems Limited | Information & communication | 1990 |
| Optimadyn Ltd | Professional & scientific | 2019 |
| Optime Group Limited | Professional & scientific | 2016 |
| Optimumcare 4U Limited | Health & social care | 2017 |
| Option One Care Services Ltd | Health & social care | 2026 |
| Options Plus 24 Ltd. | Administrative & support | 2016 |
| Oral Care Hygiene Limited | Health & social care | 2016 |
| Orange Palm Ltd | Professional & scientific | 2021 |
| Orange Projects Limited | Construction | 2008 |
| Orangeride Ltd | Transport & logistics | 2026 |
| Oraxcle Limited | Information & communication | 2025 |
| Orbis-Verde Ltd | Information & communication | 2019 |
| Orbit Peak Publisher Limited | Information & communication | 2026 |
| Orca Plumbing & Heating Limited | Construction | 2019 |
| Orchid Beauty Consultants Ltd | Professional & scientific | 2016 |
| Organic Fresh Fish and Seafood Limited | Wholesale & retail | 2023 |
| Organic Skin & Body Health Treatments Ltd | Wholesale & retail | 2019 |
| Organic Worldwide Ltd | Wholesale & retail | 2020 |
| Organiqx UK Ltd | Other services | 2019 |
| Ormtek Ltd | Information & communication | 2020 |
| Orya Global Ltd | Wholesale & retail | 2026 |
| Osiris Water Management Limited | Other services | 2007 |
| Ossl Global Limited | Professional & scientific | 2015 |
| Ostrum Tech Limited | Information & communication | 2020 |
| Otter Productions Limited | Information & communication | 2011 |
| Outbound OX Ltd | Administrative & support | 2026 |
| Outlook Academy Ltd | Administrative & support | 2025 |
| Outoner Limited | Health & social care | 2023 |
| Oval (888) Limited | Professional & scientific | 2003 |
| Ovatic Holdings Ltd | Manufacturing | 2023 |
| Over 4 YOU Ltd | Transport & logistics | 2020 |
| Ovmk Hair Ltd | Other services | 2025 |
| Ownet Limited | Professional & scientific | 2016 |
| Oxagon Ltd | Information & communication | 2005 |
| Oxshott Ltd | Wholesale & retail | 2016 |
| Oxsyst IT Consultancy Limited | Information & communication | 2006 |
| Oxted AIM Ltd | Wholesale & retail | 2020 |
| Ozke Ltd | Hospitality | 2021 |
| P & D Automotive Ltd | Wholesale & retail | 2009 |
| P & H Electrical Limited | Construction | 2005 |
| P & P Electrical Ltd | Construction | 2002 |
| P & Z Properties Ltd | Real estate | 2025 |
| P a Heighton Ltd | Professional & scientific | 2015 |
| P J Brown (Holdings) Limited | Financial services | 2021 |
| P J Brown Skips Ltd. | Extraterritorial | 2010 |
| P M W Communications Limited | Professional & scientific | 1997 |
| P N Express Ltd | Transport & logistics | 2019 |
| P N G Deliveries Ltd | Transport & logistics | 2020 |
| P&D Construct Ltd | Construction | 2025 |
| P&M Simply Spotless Ltd | Administrative & support | 2024 |
| P&R Fire and Electrical Services Ltd | Construction | 2025 |
| P-Six Ltd | Administrative & support | 2012 |
| P.G.Vallance Limited | Construction | 1963 |
| P.J.Brown (Civil Engineering) Limited | Transport & logistics | 2010 |
| P.Koev Ltd | Transport & logistics | 2017 |
| P.M.Clack & SON Limited | Real estate | 1956 |
| P3P Properties Limited | Real estate | 2017 |
| PA Parcels Ltd | Transport & logistics | 2021 |
| PA Services for YOU Limited | Health & social care | 2017 |
| PA Services Hub Limited | Administrative & support | 2024 |
| Pacegym Ltd | Arts & recreation | 2026 |
| Pacific Challenge Limited | Professional & scientific | 2021 |
| Pacific West Ltd | Real estate | 2009 |
| Packaged Performance Ltd | Wholesale & retail | 2024 |
| Packetnine Ltd | Wholesale & retail | 2011 |
| Painting by ME Ltd | Construction | 2022 |
| PAK Shakar Enterprises Ltd | Hospitality | 2018 |
| Pak-A-Punch Ltd | Manufacturing | 2024 |
| Pakpunjabi Ltd | Wholesale & retail | 2021 |
| PAL Building Ltd | Construction | 2017 |
| Palace Street Investments Limited | Real estate | 1987 |
| Palana Property Limited | Real estate | 2023 |
| Paldin Team Ltd | Transport & logistics | 2023 |
| Palmice Limited | Professional & scientific | 1984 |
| Palms Aglow Limited | Manufacturing | 2019 |
| Pampurredpets (Holdings) Limited | Financial services | 2002 |
| PAN Asia Cuisine Ltd | Hospitality | 2019 |
| Panache Brickwork Ltd | Construction | 2026 |
| Panache Painters and Decorators Limited | Construction | 2021 |
| Panash Properties Ltd | Real estate | 2026 |
| Panel Smart Limited | Wholesale & retail | 2015 |
| Pangolo Ltd | Wholesale & retail | 2023 |
| Pantheon Healthcare Ltd | Health & social care | 2022 |
| Papas Interiors Limited | Construction | 2018 |
| Papergraphics Limited | Wholesale & retail | 1983 |
| Paradise Community Initiative CIC | Administrative & support | 2026 |
| Paradise Enterprises Ltd | Construction | 2022 |
| Paradox Cleaning Ltd | Administrative & support | 2024 |
| Paragon Motor Sales Limited | Wholesale & retail | 2019 |