| Opel Electrical Services Ltd | Construction | 2018 |
| Openir Ltd | Information & communication | 2025 |
| Operate Computing Ltd | Information & communication | 2017 |
| Optic-Fm Ltd | Administrative & support | 2024 |
| Optimum Social Care Initiatives Limited | Health & social care | 2011 |
| Optimus Networks Ltd | Information & communication | 2016 |
| ORAL7 UK Operations Limited | Wholesale & retail | 2020 |
| Orbionics Ltd | Extraterritorial | 2025 |
| Orchard Manor Properties Limited | Real estate | 2025 |
| Oregen Foods Ltd | Wholesale & retail | 2024 |
| Original Friel Ltd | Financial services | 2023 |
| Orihuela Costa Property Limited | Professional & scientific | 2010 |
| Orpheus Estates Enterprises Ltd | Real estate | 2017 |
| Osteopathy Works Limited | Health & social care | 2005 |
| Ostia Property Associates Ltd | Real estate | 2023 |
| Oswip Limited | Professional & scientific | 2012 |
| OTT Software Development Ltd | Information & communication | 2021 |
| OUI Recruitment Ltd | Administrative & support | 2022 |
| OUR Finance Dept Limited | Professional & scientific | 2019 |
| Overdale Consulting Limited | Professional & scientific | 2024 |
| P & a Hurst Holdings Limited | Financial services | 2021 |
| P & D Planning Consultancy Limited | Professional & scientific | 2013 |
| P & L Fireplaces Limited | Manufacturing | 2013 |
| P B Botanicals Ltd | Wholesale & retail | 2025 |
| P B GAS Limited | Construction | 2009 |
| P Barnett Limited | Construction | 2002 |
| P C Produce Limited | Wholesale & retail | 2006 |
| P&M Hill Coaching Ltd | Professional & scientific | 2017 |
| P. Herring Services Limited | Transport & logistics | 2013 |
| P. Jackson Ltd | Extraterritorial | 2002 |
| P.D.H. Consultant Limited | Professional & scientific | 1998 |
| P17 Consulting Limited | Information & communication | 2007 |
| Paccinos Ltd | Hospitality | 2015 |
| Pace's Farm Eggs Limited | Manufacturing | 2003 |
| Pacifico Property Limited | Professional & scientific | 2009 |
| Paddle House Limited | Information & communication | 2018 |
| Paddle House Properties Ltd | Real estate | 2023 |
| Padgbury Solutions Ltd | Professional & scientific | 2021 |
| Padten Limited | Arts & recreation | 2025 |
| Paint Test Equipment Limited | Manufacturing | 2012 |
| Paint Test Instruments LLP | | 2012 |
| Pais Property Limited | Professional & scientific | 2009 |
| Pakistan World Alliance Limited | Health & social care | 2025 |
| Palace Court RTM Company Limited | Households | 2017 |
| Palmera Property Limited | Professional & scientific | 2009 |
| Pamflet Limited | Professional & scientific | 2011 |
| PAN European Networks (Holdings) Limited | Information & communication | 2011 |
| PAN European Networks Limited | Information & communication | 2011 |
| Panch Properties Ltd | Real estate | 2025 |
| Pandori Ltd | Construction | 2021 |
| Papa BEN Limited | Hospitality | 2019 |
| Park Pavilion Residents Management Company Limited | Other services | 2022 |
| Parkinson Plant Services Ltd | Administrative & support | 2017 |
| Parsonage Property Limited | Professional & scientific | 2010 |
| Patrons Franks & Sons Limited | Other services | 2025 |
| Patterns by Design Ltd | Wholesale & retail | 2023 |
| Paul Austen Associates Ltd | Professional & scientific | 2014 |
| Paul H Brooks Transport Limited | Transport & logistics | 2007 |
| Paul Joseph Sims Limited | Extraterritorial | 2025 |
| Paul Lovelle Limited | Professional & scientific | 2008 |
| Paul Sheard Autos Limited | Wholesale & retail | 1979 |
| Payfluence Ltd | Professional & scientific | 2025 |
| Payment Members Network Limited | Information & communication | 2024 |
| Pbinnsnorthwest Limited | Hospitality | 2024 |
| PCB Europe Limited | Information & communication | 2015 |
| Pcoskiller Ltd | Wholesale & retail | 2024 |
| PCS Process Solutions Limited | Manufacturing | 2025 |
| PDO Install Ltd | Construction | 2019 |
| Peak Fuels and Renewables Ltd | Wholesale & retail | 2023 |
| Peak View Construction Ltd | Construction | 2022 |
| Peaks Sports Management Limited | Professional & scientific | 2022 |
| Peanut and Pickle Ltd | Wholesale & retail | 2021 |
| Pear Tree Play Therapy Limited | Education | 2025 |
| Pearl Elliott Associates Ltd | Professional & scientific | 2023 |
| Peggy's Promise to Care Limited | Health & social care | 2022 |
| Pension App Ltd | Financial services | 2022 |
| Pension App Trustees Ltd | Financial services | 2025 |
| Pension Tax Consulting Ltd. | Professional & scientific | 2017 |
| Pentland House Limited | Professional & scientific | 1987 |
| Peoplecoach Limited | Professional & scientific | 2021 |
| Peptideme Ltd | Health & social care | 2025 |
| Perchrose Investments Ltd | Construction | 2024 |
| Pericare Private Limited | Health & social care | 2026 |
| Perpetual Gladness Ltd | Real estate | 2021 |
| Perpetuwealth Ltd | Information & communication | 2026 |
| Pest in Peace Ltd | Administrative & support | 2016 |
| Pet Care, Cheshire Limited | Professional & scientific | 2015 |
| Peter Cliff & Sons Limited | Professional & scientific | 2015 |
| Peter Lynch Consulting Limited | Professional & scientific | 2013 |
| Pett Ltd | Administrative & support | 2016 |
| PGS Grounds & Trees Ltd | Administrative & support | 2017 |
| Phantm UK Ltd | Information & communication | 2026 |
| Pharmacare Group Ltd | Professional & scientific | 2021 |
| Pharmacare Holdings Ltd | Financial services | 2025 |
| PHD Architects Limited | Professional & scientific | 2018 |
| Philip Kelsall Building Design and Consultancy Limited | Professional & scientific | 2003 |
| Phoenix Investments International Limited | Other services | 2020 |
| Phone Stop Congleton Ltd | Wholesale & retail | 2023 |
| Phonecareuk Ltd | Wholesale & retail | 2021 |
| Phonetic Holdings Limited | Financial services | 2019 |