| Office Essentials (Wirral) Limited | Administrative & support | 2005 |
| Office Services (Nantwich) Limited | Wholesale & retail | 1965 |
| Ogcb Peelhouse Associates | | 1992 |
| Ogden Townsend Limited | Professional & scientific | 2002 |
| Ojewellery Ltd | Wholesale & retail | 2021 |
| Olimax Services Limited | Professional & scientific | 2017 |
| Oliver Valves Limited | Manufacturing | 1979 |
| Oliver Valvetek Limited | Manufacturing | 1994 |
| Omaze UK Holdco Limited | Administrative & support | 2025 |
| OMR Assets Limited | Real estate | 2025 |
| OMR Holdings Limited | Financial services | 2025 |
| ON Site Truck Repairs Limited | Manufacturing | 1993 |
| One and ALL Limited | Information & communication | 2000 |
| One Ecolab Pension Plan Trustee Limited | Extraterritorial | 2006 |
| One Point 61 Limited | Professional & scientific | 2007 |
| Onom Limited | Real estate | 2006 |
| Onyx Electrical Engineering Limited | Construction | 2023 |
| Opti Robust Solutions Ltd | Professional & scientific | 2006 |
| Optimus Plus (Aberdeen) Limited | Professional & scientific | 2022 |
| Optisol Services Ltd | Construction | 2016 |
| Optonomy Limited | Information & communication | 2013 |
| Orchard Business Systems Limited | Manufacturing | 1997 |
| Orchard Consulting Limited | Professional & scientific | 2003 |
| Origin Business Solutions Limited | Information & communication | 1999 |
| Orion Engineering Ltd | Professional & scientific | 1997 |
| Orwell Letting Limited | Real estate | 2003 |
| Osborne Assets Limited | Extraterritorial | 1993 |
| Osborne House Limited | Construction | 1983 |
| Oswalds Limited | Hospitality | 2005 |
| Outburst Ltd | Real estate | 2006 |
| Outdoor & Sports Company (Holdings) Limited | Professional & scientific | 1991 |
| Outhwaite & Chavda Limited | Financial services | 2000 |
| Ovalseal Limited | Professional & scientific | 1989 |
| Oven Cleaning Demon Ltd | Administrative & support | 2016 |
| Overdee Consulting Limited | Real estate | 2002 |
| Overwood Consulting Limited | Professional & scientific | 2000 |
| Owen Brothers Roofing Limited | Construction | 2005 |
| OWP Limited | Information & communication | 2004 |
| P & C Eyewear Limited | Administrative & support | 2006 |
| P & J Robinson (Electrical) Ltd | Construction | 2004 |
| P & M Panels Limited | Wholesale & retail | 2005 |
| P & S M Wilson Contractors Limited | Construction | 2004 |
| P Harper Builders Limited | Construction | 1998 |
| P Huxham & Associates Limited | Professional & scientific | 2007 |
| P I Enterprises Limited | Professional & scientific | 1998 |
| P K Hardy Limited | Professional & scientific | 2003 |
| P K Stubbs Limited | Wholesale & retail | 2007 |
| P S Hollinshead Limited | Real estate | 2006 |
| P Sharwin Consulting Ltd | Professional & scientific | 2007 |
| P. & a. Motorcycles Limited | Wholesale & retail | 1993 |
| P. Derbyshire & Sons (Property) Limited | Real estate | 1949 |
| P.H.M. (Peat) Limited | Real estate | 1960 |
| P.J. Combustion Solutions Ltd | Manufacturing | 2002 |
| P.J. Toft Limited | Construction | 2005 |
| P.W. Quality GAS Services Limited | Other services | 2003 |
| PA Group (UK) Limited | Construction | 2007 |
| Pace Arclid Limited | Administrative & support | 1959 |
| Pace Health & Fitness Ltd | Arts & recreation | 2007 |
| Paddock Bakeries Limited | Manufacturing | 1972 |
| Padel Events Ltd | Arts & recreation | 2026 |
| Padgbury Designs Limited | Professional & scientific | 1994 |
| Paint Auto Craft Limited | Wholesale & retail | 1980 |
| Pakdata Limited | Information & communication | 2022 |
| Pambryn Properties Limited | | 1981 |
| Panacea Ltd | Real estate | 2025 |
| Panache (GB) Ltd | Other services | 2003 |
| Panels & Coatings Limited | | 1987 |
| Paradigm Partners Limited | Financial services | 2015 |
| Paradigm Partners Trustee NO.2 Limited | Financial services | 2017 |
| Park & Paterson (Manchester) Limited | Professional & scientific | 1914 |
| Park Mews (Darfield) Management Company Limited | Real estate | 2019 |
| Parkgate Property Management Limited | Real estate | 2019 |
| Parkhod Limited | Professional & scientific | 1986 |
| Parkinson Howe Limited | Information & communication | 1997 |
| Parkleigh Management (Congleton) Limited | Real estate | 2003 |
| Parkway Group Holdings Ltd | Financial services | 2022 |
| Parrotts of Cheshire Limited | Professional & scientific | 2001 |
| Partkey Limited | | 1984 |
| Partnership Property Consultants Limited | Professional & scientific | 1991 |
| PAS Design Services Limited | Professional & scientific | 1998 |
| Path Wellbeing Ltd | Professional & scientific | 2004 |
| Pathfinder Management Services Ltd | Professional & scientific | 2007 |
| Patrick Rooney Associates Ltd | Extraterritorial | 2006 |
| Patriot Printing Solutions Limited | Manufacturing | 2005 |
| Pats Coaches Limited | Transport & logistics | 2002 |
| Paul Alvarez Ltd | Construction | 2012 |
| Paul Carter Limited | Construction | 2003 |
| Paul D Brown Limited | Information & communication | 2007 |
| Paul Yates Flooring Ltd | Construction | 2006 |
| Paul's Tool Emporium Limited | Wholesale & retail | 2000 |
| Paystream My MAX 2 Limited | Administrative & support | 2007 |
| PBA Recovery Ltd | Transport & logistics | 2020 |
| PBX Petrochemical Limited | Wholesale & retail | 2005 |
| PC Express Business Limited | Information & communication | 2007 |
| Pcmoto UK Limited | Wholesale & retail | 2015 |
| PD & MS (Dundee) Limited | Manufacturing | 2011 |
| PD Print Limited | Manufacturing | 1997 |
| Pd&Ms Holdings Limited | Professional & scientific | 2013 |
| PDE Construction Ltd | Extraterritorial | 2007 |
| Peacegaze Limited | Professional & scientific | 2003 |