| OSL Investment Limited | Real estate | 2023 |
| Ourver Ltd | Wholesale & retail | 2016 |
| OV Essex Limited | Transport & logistics | 2023 |
| Oxara London Limited | Professional & scientific | 2022 |
| O’Reilly GAS Ltd | Construction | 2020 |
| P and G Engineering Limited | Manufacturing | 1982 |
| P R Machine Tools Limited | Manufacturing | 2006 |
| P&K Trans Limited | Administrative & support | 2016 |
| P.Boshnjaku Investment Ltd | Other services | 2025 |
| Packaged Pumps Systems Limited | Manufacturing | 2007 |
| Pactis Partners Limited | Professional & scientific | 2025 |
| Paddock Residential Limited | Households | 2026 |
| Padel Retreats Ltd | Administrative & support | 2025 |
| Padnall Printers Limited | Manufacturing | 1973 |
| Pages Bookkeeping Ltd | Professional & scientific | 2018 |
| Paige Braille Ltd | Manufacturing | 2022 |
| Paisa Wine Bar Ltd | Hospitality | 2022 |
| Paliev Ltd | Real estate | 2013 |
| Pallium Estates Limited | Financial services | 2018 |
| Panacea Palm Ltd | Information & communication | 2023 |
| Panas Ventures Limited | Professional & scientific | 2024 |
| Pandanest Ltd | Administrative & support | 2019 |
| Panel Sell Ltd | Professional & scientific | 2012 |
| Papanas Ltd | Hospitality | 2025 |
| Paper Projects Limited | Other services | 2002 |
| Paracase Ltd | Health & social care | 2026 |
| Paradigm Resources Ltd | Professional & scientific | 2009 |
| Parc Properties Limited | Real estate | 1991 |
| Parchett Limited | Mining & quarrying | 1982 |
| Parker Clinical Psychology Limited | Health & social care | 2019 |
| Partners in Purchasing Limited | Administrative & support | 1997 |
| Pasha 27 Ltd | Other services | 2023 |
| Pasha Property Management Ltd | Real estate | 2020 |
| Pasha Taxis Limited | Other services | 2015 |
| Pasii Limited | Wholesale & retail | 2023 |
| Passionate About Pets Animal Physiotherapy Ltd | Professional & scientific | 2014 |
| Pasture Fields Management Limited | Households | 2024 |
| Patan Limited | Other services | 2022 |
| Path Five Ltd | Professional & scientific | 2020 |
| Path to Wellbeing - Herbs and Acupuncture Ltd | Health & social care | 2021 |
| Patrician Management Ltd | Professional & scientific | 2022 |
| Patterns of Business Ltd | Professional & scientific | 2025 |
| Pavilion Place Advisory Ltd | Health & social care | 2022 |
| Paye Easy Ltd | Professional & scientific | 2023 |
| Payne Waldron Consulting Ltd | Professional & scientific | 2023 |
| Paytopia Ltd | Information & communication | 2025 |
| PB Causeway House Limited | Financial services | 2016 |
| PB Trustee Co. Limited | Extraterritorial | 1998 |
| PCM Business Services Limited | Professional & scientific | 2019 |
| PCR Property Services Ltd | Real estate | 2019 |
| PDS Utilities Ltd | Professional & scientific | 2022 |
| Peanut Pet Fashion Ltd | Wholesale & retail | 2024 |
| Pearse House Management Company Limited | Households | 2014 |
| Pebble Speech and Language Therapy Ltd | Education | 2026 |
| Pebl Property Ltd | Real estate | 2019 |
| PEC Sports Ltd | Education | 2018 |
| Pedites Properties Ltd | Real estate | 2022 |
| Peek Management Limited | Households | 2016 |
| Pendleton & Cross Limited | Wholesale & retail | 2015 |
| Pendroply Ltd | Information & communication | 2026 |
| Penn Carpentry & Joinery Limited | Construction | 2000 |
| Peopleflow.Ai Ltd | Administrative & support | 2024 |
| Pepples Property Ltd | Real estate | 2020 |
| Percy Consulting Ltd | Construction | 2019 |
| Perfect Reflections Ltd | Professional & scientific | 2018 |
| Performance Learning Group Ltd | Education | 2015 |
| Perko Productions Limited | Information & communication | 2020 |
| Persanti Homes Ltd | Construction | 2019 |
| Persanti Ltd | Construction | 2019 |
| Persephone Marketing Limited | Administrative & support | 2023 |
| Pestell of Bishops Stortford Ltd | Real estate | 2009 |
| Pestforce Hertfordshire Limited | Agriculture & fishing | 2019 |
| Pestforce ST Albans Limited | Agriculture & fishing | 2020 |
| Peter Hilton Ltd | Wholesale & retail | 1995 |
| Peter Knight Consulting Group Ltd | Administrative & support | 2012 |
| Peter Knight HR Services Ltd | Administrative & support | 2013 |
| Peter Neurotech Ltd | Manufacturing | 2025 |
| Peter Perkins Electrical Limited | Other services | 2003 |
| Peterborough Carpentry Ltd | Manufacturing | 2019 |
| Peterstech Automobile Ltd | Wholesale & retail | 2022 |
| Petite Belle Ltd | Wholesale & retail | 2019 |
| Petrov&Sons Services Limited | Construction | 2004 |
| PFN Enterprise Ltd | Construction | 2024 |
| PG Diesels Ltd | Wholesale & retail | 2023 |
| Phil Carpenter Health and Fitness Limited | Other services | 2023 |
| Philduf Ltd | Health & social care | 2013 |
| Phoenix Group Services Ltd | Transport & logistics | 2018 |
| Phoenix Lodge Ltd | Hospitality | 2013 |
| Phyllis Homes Ltd | Construction | 2021 |
| Picardy Close Management Company Limited | Real estate | 2015 |
| Piggott Coachbuilders Limited | Manufacturing | 2003 |
| Pilates Training Hub Ltd | Education | 2024 |
| Pinches Consulting Ltd | Professional & scientific | 2020 |
| Pineacre Construction Limited | Construction | 2015 |
| Pineacre Group Limited | Financial services | 2023 |
| Pineacre Homes Limited | Construction | 2016 |
| Pineacre Investments Ltd | Financial services | 2026 |
| Pineapple Bars Ltd | Hospitality | 2025 |
| Pink Wombat Limited | Information & communication | 2019 |
| Pippa Jameson Interiors Ltd | Professional & scientific | 2014 |