| Ogv/Lbs Engineering Support Group Ltd | Construction | 2023 |
| Okhun Ltd | Administrative & support | 2017 |
| Old Michelmersh Farm Trust Limited | Other services | 1979 |
| Old Poultry Shed Limited | Arts & recreation | 2022 |
| Olima Medical Limited | Health & social care | 2019 |
| Olin & Harlie Ltd | Administrative & support | 2017 |
| Oliv TR Ltd | Hospitality | 2023 |
| Oliver MP Ltd | Professional & scientific | 2020 |
| Olney Mortgages Limited | Administrative & support | 2006 |
| Olree Limited | Real estate | 2020 |
| Olympus Carpentry Limited | Construction | 2017 |
| Omega Land Assets Limited | Real estate | 2024 |
| Omniverse Comics Guide Ltd | Information & communication | 2023 |
| ON the Street Property Ltd | Real estate | 2007 |
| Onboard Enterprises Limited | Professional & scientific | 2014 |
| Ontap Media Ltd | Information & communication | 2017 |
| Onyx House Publishing Limited | Information & communication | 2025 |
| Ophionyx Equities LLP | | 2025 |
| Optima Project Solutions Limited | Professional & scientific | 2023 |
| Optimosys Ltd | Professional & scientific | 2022 |
| Optimum Function Limited | Health & social care | 2004 |
| Optionb Limited | Information & communication | 2012 |
| Optionb Property Limited | Real estate | 2015 |
| Orchard (Shamblehurst Lane North) Limited | Construction | 2013 |
| Orchard Anaesthesia Limited | Health & social care | 2012 |
| Oriana Partners Consulting Ltd | Professional & scientific | 2025 |
| Orio Investments Limited | Real estate | 2017 |
| Orisha Building Services Ltd | Construction | 2022 |
| Orman Properties Limited | Extraterritorial | 2004 |
| Osborne Brown Limited | Construction | 2022 |
| OSM Merchants Platform Limited | Administrative & support | 2020 |
| Ostrov Ltd | Transport & logistics | 2015 |
| Ot-Rehab Ltd | Health & social care | 2021 |
| Otterbourne Golf Company Limited | Arts & recreation | 1994 |
| OUR Business Hub CIC | Other services | 2025 |
| Outdoor Spaces Ltd | Administrative & support | 2019 |
| Oxalis Multicare Ltd | Health & social care | 2024 |
| Oxford Pocus Limited | Health & social care | 2025 |
| Oxford Spine Solutions Limited | Health & social care | 2013 |
| Oxlease Boundary Ltd | Extraterritorial | 2021 |
| Oxley Farm Solar Park Limited | Energy | 2014 |
| P D Anaesthetics Limited | Health & social care | 2022 |
| P J M Trustees Limited | Administrative & support | 2011 |
| P Keld Limited | Construction | 2015 |
| P.C.M.R. Limited | Construction | 2010 |
| P.T.R. Thornton & Co Limited | Professional & scientific | 2023 |
| Pace Facade Systems Limited | Construction | 2023 |
| Pace Roofing (Solutions) Limited | Construction | 2014 |
| Pace Roofing Limited | Construction | 1995 |
| Pack TEC UK Limited | Administrative & support | 2025 |
| Packridge Lettings Ltd | Real estate | 2025 |
| Paddock Holdings Limited | Real estate | 2016 |
| Paediatric Cardiology Bristol Limited | Health & social care | 2023 |
| Paige Associates Limited | Professional & scientific | 2002 |
| Palmer Property Management Ltd | Real estate | 2021 |
| Pandalin Systems Limited | Manufacturing | 2007 |
| Pandalin UK Limited | Manufacturing | 2005 |
| Panetti Medical Limited | Health & social care | 2025 |
| Papadum Restaurant Limited | Hospitality | 2025 |
| PAR Carpentry Ltd | Manufacturing | 2017 |
| Paramount Scaffolding Solutions Limited | Construction | 2016 |
| Parisinos Healthcare Ltd | Health & social care | 2023 |
| Parker-Fellows Homes Ltd | Real estate | 2017 |
| Parkside Business Solutions Limited | Professional & scientific | 2011 |
| Pars Consilium Limited | Professional & scientific | 2018 |
| Particular Pots Ltd | Wholesale & retail | 2020 |
| Patrimonium IC Limited | Real estate | 2026 |
| Paul Spooner Design Limited | Professional & scientific | 2016 |
| Paultons Properties Limited | Real estate | 2022 |
| Pavilion Events Ltd. | Arts & recreation | 2020 |
| Paws for Thought Cat Cafe Ltd | Hospitality | 2017 |
| PAX Eyewear Limited | Health & social care | 2012 |
| Paye.Com Ltd | Professional & scientific | 2004 |
| PB Maidment Ltd | Administrative & support | 2022 |
| PCH (Winchester) Ltd | Construction | 2017 |
| Pco.T Limited | Health & social care | 2016 |
| Peak 9 Medical Limited | Professional & scientific | 2022 |
| Peak Energy Ltd | Professional & scientific | 2001 |
| Pearsonclinic Limited | Health & social care | 2017 |
| Pedestal Education Services Ltd | Information & communication | 2023 |
| Pegasus Plumbers Ltd | Construction | 2019 |
| Pelleas Construction Ltd | Construction | 2024 |
| Pelleas Homes Limited | Construction | 2024 |
| Pelleas Homes M5 Ltd | Construction | 2025 |
| Pembroke House Estate Residents Association Limited | Households | 2004 |
| Pembury Projects Limited | Real estate | 1997 |
| Pendl Properties Ltd | Real estate | 2026 |
| Penn Hill Anaesthetists Limited | Health & social care | 2014 |
| Pennington, Jones (H.I.) Limited | Construction | 2009 |
| Pension Ready Ltd | Financial services | 2008 |
| Perfect Awnings Limited | Wholesale & retail | 2025 |
| Personal Touch Financial Services (Solent) Limited | Financial services | 2006 |
| Pet Capital Ltd | Financial services | 2021 |
| Peter H Finch Limited | Professional & scientific | 2006 |
| Peter Jorgensen Limited | Real estate | 2020 |
| Peter Lloyd Legal Limited | Professional & scientific | 2014 |
| Peter Symonds Limited | Manufacturing | 2015 |
| Peter Symonds Property Limited | Real estate | 2018 |
| Pgordonbennett.Com Ltd | Health & social care | 2021 |
| Phase Elec Contractors Ltd | Construction | 2025 |