| Nuskiin Ltd | Other services | 2023 |
| NYE & Co Hungerford Limited | Real estate | 2002 |
| O'Brien & SON Roofing and Leadwork Specialists Ltd | Construction | 2024 |
| O-1 Aviation Ltd | Manufacturing | 2017 |
| Oakdene Care (Shropshire) Limited | Health & social care | 2012 |
| Oakdene Care Providers Limited | Health & social care | 2026 |
| Ocean Fish Foods Limited | Hospitality | 2024 |
| Odysseus Cleanslate Limited | Professional & scientific | 2013 |
| Odyssey Capital Ltd | Professional & scientific | 2020 |
| Officemaster Limited | Information & communication | 1985 |
| OGH Building & Landscaping Limited | Construction | 2021 |
| OJB Services Limited | Administrative & support | 2010 |
| Old Granary Flat Management Company Limited(The) | Households | 1983 |
| Olive Ventures Ltd | Real estate | 2026 |
| Oliver Signy Racing LLP | | 2019 |
| OM3GA Limited | Professional & scientific | 2025 |
| Ombiy Limited | Information & communication | 2019 |
| Omicron Research Limited | Professional & scientific | 1992 |
| Omnilocate Technologies Ltd Ltd | Information & communication | 2026 |
| Oneiro Yacht Charters Limited | Transport & logistics | 2023 |
| Onlypens Ltd | Manufacturing | 2019 |
| Operite Consulting Ltd | Professional & scientific | 2020 |
| ORB Commercial Property Limited | Real estate | 2012 |
| Orbihire Welding Services Limited | Professional & scientific | 2020 |
| Oriole Bar Ltd | Hospitality | 2023 |
| Orleot Limited | Financial services | 2021 |
| Ottermill (Hungerford) Management Company Limited | Households | 1987 |
| Ottsella Ltd | Real estate | 2024 |
| Outside Ideas Ltd | Administrative & support | 2021 |
| OWL Building Control Solutions Limited | Construction | 2013 |
| Oxygen Photography Ltd | Professional & scientific | 2018 |
| P J Day Ltd | Administrative & support | 2018 |
| P&E Dreams Ltd | Wholesale & retail | 2024 |
| P.J.N. Trundle Limited | Wholesale & retail | 1982 |
| P.J.S. (Agricultural Services) Limited | Manufacturing | 1981 |
| P2PL Limited | Professional & scientific | 2020 |
| Paelleros Direct Limited | Wholesale & retail | 2011 |
| Palady Developments (Mill Lane) Limited | Real estate | 2022 |
| Palady Developments (Newtown Road) Limited | Real estate | 2017 |
| Palady Developments (Valley Road) Ltd | Real estate | 2019 |
| Palady Developments (Ventures) Limited | Administrative & support | 2004 |
| Palady Developments Limited | Construction | 2003 |
| Pallet Express Ltd | Transport & logistics | 2026 |
| Pallet Logistics Ltd | Transport & logistics | 2026 |
| Palmer Construction Services Ltd | Professional & scientific | 2018 |
| Panoplytics Limited | Professional & scientific | 2019 |
| Paramotor Training Ltd | Professional & scientific | 2016 |
| Parker Asset Management Limited | Real estate | 2009 |
| Parso-Supplies Ltd | Wholesale & retail | 2025 |
| Parsonage House Lambourn Limited | Households | 1999 |
| Paul Wigmore Electrical Contractors Limited | Construction | 2014 |
| Pause Partnership Ltd | Professional & scientific | 2022 |
| Pavier Limited | Construction | 2012 |
| PAW and Disorder Dog Training Ltd | Other services | 2026 |
| Paws to Remember Ltd | Wholesale & retail | 2026 |
| PBA Accountants and Business Advisers Ltd | Professional & scientific | 2008 |
| PBA Accountants LLP | | 2012 |
| PCS Facilities Limited | Administrative & support | 2011 |
| Peak Hill Investments Corporation Limited | Real estate | 2021 |
| Peeling Limited | Construction | 2023 |
| Pendragon Risk Management Ltd | Administrative & support | 2014 |
| Penny Post Limited | Information & communication | 2015 |
| Penny Post Publishing CIC | Information & communication | 2022 |
| Pennybar Contracting Limited | Real estate | 2024 |
| Pennybar Developments Limited | Real estate | 2023 |
| Perform EDU LLP | | 2023 |
| Perspicio Limited | Professional & scientific | 2014 |
| Pete the Sweep Limited | Administrative & support | 2024 |
| Phase 3 Medical Communications Limited | Information & communication | 2018 |
| Phase Lifestile UK Ltd | Construction | 2018 |
| Philip Brindley International Limited | Administrative & support | 2017 |
| Philip Mitchell Horse Transport Ltd | Transport & logistics | 2021 |
| Phytoactiv Ltd | Manufacturing | 2019 |
| Pillarbox Property Limited | Real estate | 2016 |
| Pipework & Welding Contracting Services Limited | Manufacturing | 2010 |
| Pipework and Welding Services Limited | Real estate | 1969 |
| Pipptech Ltd | Information & communication | 2023 |
| Piremus Limited | Professional & scientific | 2020 |
| Pitch 15 Properties Limited | Real estate | 2019 |
| Planet Earth Media Limited | Professional & scientific | 2026 |
| Platform Eighteen Entertainment Limited | Hospitality | 2026 |
| Platform Eighteen Properties Limited | Professional & scientific | 2026 |
| Plattmounts Europe Ltd | Wholesale & retail | 2006 |
| POP Cycling Co Limited | Wholesale & retail | 2023 |
| POP Running Co Limited | Wholesale & retail | 2025 |
| Poppy Love Soft Furnishings Ltd | Wholesale & retail | 2013 |
| Poppymill Limited | Real estate | 2016 |
| Port of Leverburgh (Land) Ltd | Construction | 2007 |
| Portman Square West Village Reading Management Company Limited | Households | 2012 |
| Povey (Properties) Limited | Real estate | 2009 |
| Powderpuff Beauty Limited | Other services | 2026 |
| Premium Pointing Ltd | Construction | 2025 |
| Premtext Limited | Construction | 2001 |
| Prenderville Building and Maintenance Limited | Construction | 2015 |
| Pridelord Groundworks Limited | Construction | 2009 |
| Priors Court Containers Ltd | Transport & logistics | 2023 |
| Pritchett Advisory Limited | Professional & scientific | 2018 |
| PROC2W Limited | Wholesale & retail | 2016 |
| Property Developments Wessex Limited | Real estate | 2007 |
| Prosper Hill LLP | | 2019 |