| OCL Regeneration Limited | Other services | 2006 |
| Octado Limited | Other services | 2023 |
| Odyssey HQ Ltd | Manufacturing | 2025 |
| Ogden Roadstone Limited | Professional & scientific | 1970 |
| OH SEW Splendid CIC | Education | 2022 |
| Olasupo Gaizer Ltd | Health & social care | 2023 |
| Old Sarum Park Properties Limited | Professional & scientific | 1987 |
| Olive Tree Lettings Ltd | Real estate | 2024 |
| OMA Holdings Ltd | Professional & scientific | 2020 |
| Omni Trading Limited | Real estate | 2008 |
| One More 4 Sound Limited | Information & communication | 2009 |
| Onore Ltd | Manufacturing | 2024 |
| Optilux Limited | Professional & scientific | 2007 |
| Optimus Point Management Company Limited | Other services | 2015 |
| Orange 66 Ltd | Wholesale & retail | 2021 |
| Orange and Black Resources Limited | Professional & scientific | 2016 |
| Orange UK Group Ltd | Water & waste | 2020 |
| Orca Learning Ltd | Education | 2024 |
| Oregon Timber Frame (England) Limited | Construction | 2006 |
| Organico Limited | Wholesale & retail | 1988 |
| Orior FX Limited | Construction | 2002 |
| Orpheus Consulting Engineers Limited | Professional & scientific | 2005 |
| Oscar and SID Limited | Administrative & support | 2013 |
| Otct Limited | Construction | 2025 |
| Oura Consultancy Ltd | Professional & scientific | 2025 |
| Outpoint Motors Limited | Wholesale & retail | 2015 |
| Owen Williams Limited | Construction | 2014 |
| Oxed International Ltd | Education | 2024 |
| Oxed Limited | Information & communication | 2019 |
| O’Byrne Living Limited | Real estate | 2026 |
| P & R Building Supplies Limited | Wholesale & retail | 1987 |
| P a Jones Limited | Other services | 2016 |
| P a Roofing and Building Limited | Construction | 2002 |
| P Boshell Ltd | Information & communication | 2012 |
| P Else Building Services Ltd | Construction | 2018 |
| P Harcombe Ltd | Transport & logistics | 2020 |
| P. J. Dawson Malone Ltd | Professional & scientific | 2007 |
| P. Peterson Ltd | Transport & logistics | 2010 |
| P.A. Davis (Transport) Limited | Transport & logistics | 2002 |
| P.J. Thory Limited | Transport & logistics | 1976 |
| P.K.M. Kryccy Limited | Transport & logistics | 2025 |
| P.L. Textiles Limited | Real estate | 1985 |
| Padda (UK) Limited | Wholesale & retail | 2010 |
| Paint Perfection Decorating Ltd | Construction | 2026 |
| Painting by Nicholas Ltd | Construction | 2024 |
| PAL Hygiene Limited | Extraterritorial | 1982 |
| PAL International Holdings Limited | Financial services | 2022 |
| PAL International Investments Limited | Financial services | 2022 |
| PAL International Limited | Manufacturing | 1996 |
| Pall-Ex Asia Limited | Financial services | 2020 |
| Pall-Ex Europe Limited | Transport & logistics | 2020 |
| Pall-Ex International Limited | Transport & logistics | 2000 |
| Pall-Ex Investments Limited | Financial services | 2019 |
| Pall-Ex North America Limited | Extraterritorial | 2021 |
| Pall-Ex Trustee and Nominee Limited | Administrative & support | 2020 |
| Palm Island Tanning Ltd | Other services | 2019 |
| Palmers PH Group Ltd | Financial services | 2021 |
| Palmers PH Ltd | Construction | 2021 |
| Palmers PHP Ltd | Construction | 2021 |
| Pammys Kitchen Ltd | Manufacturing | 2024 |
| Paper Sun Touring Limited | Information & communication | 2026 |
| Papilio Furniture Trading Limited | Manufacturing | 2024 |
| Paragon Building Limited | Construction | 2015 |
| Paragon Materials Limited | Extraterritorial | 2000 |
| Parsonwood Properties Ltd | Real estate | 2024 |
| Parth Retail Ltd | Wholesale & retail | 2022 |
| Partners in Programmes Limited | Information & communication | 2013 |
| Partners in Travel Ltd | Administrative & support | 2024 |
| Partsleicester Ltd | Wholesale & retail | 2025 |
| Passenger Travel Solutions Ltd | Transport & logistics | 2019 |
| Pastoral Coaching Limited | Education | 2025 |
| Pathfinder Digital Consultancy Ltd | Information & communication | 2023 |
| Patient Care Locally Community Interest Company | Health & social care | 2011 |
| Paul J Davis Limited | Professional & scientific | 2012 |
| PAV Electrical Limited | Construction | 2017 |
| Paysmarter Limited | Wholesale & retail | 2024 |
| PBX Transport Ltd | Transport & logistics | 2020 |
| PC Network Consulting Limited | Information & communication | 2004 |
| Pdwc Limited | Construction | 2025 |
| Pearl Homes & Property Group Limited | Real estate | 2025 |
| Pebody Properties Limited | Real estate | 2013 |
| Peckleton Retail Limited | Wholesale & retail | 2004 |
| Pegg Properties Ltd | Real estate | 2016 |
| Peking House Takeaway Ltd | Hospitality | 2022 |
| Pelczar Ltd | Hospitality | 2022 |
| Penan Properties Limited | Real estate | 2021 |
| Perfect Bedrooms & Kitchens Ltd | Manufacturing | 2019 |
| Perkins Independent Wine Traders Limited | Wholesale & retail | 2009 |
| Personal Touch Care Ltd | Professional & scientific | 2012 |
| Personal Touch Project CIC | Health & social care | 2021 |
| Pete Motors Limited | Wholesale & retail | 2023 |
| Peter R. Beck Engineering Services Limited | Professional & scientific | 1977 |
| Peter Wileman Photography Limited | Professional & scientific | 2015 |
| Petronius Property Limited | Real estate | 2024 |
| Pharmacogene Research Ltd | Professional & scientific | 2019 |
| Phase Five Creative Ltd | Financial services | 2024 |
| Phil Lewis (Haulage) Limited | Transport & logistics | 2003 |
| Phoenix IP Holdings Limited | Information & communication | 2023 |
| Photo Panda Ltd | Wholesale & retail | 2020 |
| Photolux Limited | Professional & scientific | 2014 |