| Oorja Associates Limited | Real estate | 2026 |
| Openstor 1 Limited | Transport & logistics | 2026 |
| Orange Sales and Lettings Limited | Real estate | 2019 |
| Orthoptic Supplies Limited | Wholesale & retail | 2013 |
| Orzo Gaming Ltd | Other services | 2020 |
| OUD Imperial Limited | Wholesale & retail | 2024 |
| Outdoor Retailers Limited | Wholesale & retail | 2021 |
| Owens Heating & Plumbing Limited | Construction | 2019 |
| Own the Place! LLP | | 2018 |
| Oxard Limited | Health & social care | 2022 |
| Oxstalls Farm LLP | | 2022 |
| Oyedele Isaac Odeniran Property Holdings LLP | | 2018 |
| Ozkan Family Partnership LLP | | 2021 |
| Ozmo Developments Ltd | Construction | 2025 |
| P & S Hendy WP Ltd | Administrative & support | 2024 |
| P Hanratty WP Ltd | Administrative & support | 2024 |
| P Leavers & K Kinsella WP Ltd | Administrative & support | 2024 |
| P Marshall Consulting Ltd | Professional & scientific | 2025 |
| P Smith WP Ltd | Professional & scientific | 2024 |
| P Wylie Groundworks Ltd | Construction | 2023 |
| P&R Consulting Ltd | Professional & scientific | 2022 |
| P. C. Training Services Limited | Education | 2025 |
| P.A.S. Properties Limited | Real estate | 2003 |
| PA Construction Services Limited | Construction | 2026 |
| Pabila Family Partnership LLP | | 2022 |
| Pacific Keys Ltd | Financial services | 2025 |
| Padel VUE Limited | Arts & recreation | 2026 |
| Padelchaps Ltd | Wholesale & retail | 2026 |
| Padsoft Limited | Information & communication | 2021 |
| PAF IT Projects Limited | Information & communication | 2014 |
| Paintwork Dunn Limited | Manufacturing | 2017 |
| Paisley Worldwide Limited | Professional & scientific | 2017 |
| Palm International Ltd | Wholesale & retail | 2025 |
| Pambestpractice Ltd | Education | 2024 |
| Pankaj & Preeya Mehra Family Partnership LLP | | 2020 |
| Panton Akins Family Holdings Limited | Real estate | 2018 |
| Panton Akins Family Partnership LLP | | 2018 |
| Paralloy Group Holdings Limited | Financial services | 2024 |
| Paralloy Group Limited | Financial services | 2019 |
| Paralloy Limited | Manufacturing | 1931 |
| Parijaat Limited | Professional & scientific | 2016 |
| Park Family Limited | Wholesale & retail | 2026 |
| Park Housing Ltd | Real estate | 2026 |
| Parker Autosport Ltd | Wholesale & retail | 2025 |
| Parker Bespoke Joinery & Building Limited | Construction | 2021 |
| Parker Family Partnership LLP | | 2016 |
| Parkplus Limited | Administrative & support | 2012 |
| PAS Property Partnership LLP | | 2022 |
| Path Property Partnership LLP | | 2020 |
| Pattern Crete Products Ltd | Administrative & support | 2022 |
| Paul ALI Inspection Limited | Construction | 2010 |
| Paul Gibson Limited | Real estate | 2022 |
| Paul Maintenance & Construction Ltd | Construction | 2025 |
| Paul Messham Limited | Professional & scientific | 1979 |
| Paul Young Logistics Ltd | Transport & logistics | 2025 |
| Pause for Coffee Limited | Wholesale & retail | 2024 |
| PCJ Homes Ltd | Real estate | 2020 |
| PCS Detailing Limited | Wholesale & retail | 2018 |
| Peace Garden Management Limited | Households | 2019 |
| Penny Bailey Recruitment & Training Ltd | Administrative & support | 2004 |
| Penpoint Limited | Administrative & support | 2017 |
| Performance Matters Limited | Professional & scientific | 2011 |
| Periplus Inspection Services Limited | Professional & scientific | 2019 |
| Perses International Ltd | Professional & scientific | 2023 |
| Pet Nurse Services Limited | Professional & scientific | 2016 |
| Peter English Carpets & Flooring Limited | Wholesale & retail | 2019 |
| Peter Larmouth Limited | Wholesale & retail | 2007 |
| Peters Fast Food Ltd | Hospitality | 2011 |
| Petitedone Ltd | Wholesale & retail | 2026 |
| PFT Northeast Limited | Administrative & support | 2025 |
| PGL Trades Limited | Construction | 2019 |
| Pharar Family Holdings Ltd | Real estate | 2018 |
| Pharar Family Partnership LLP | | 2018 |
| Phare Financial Services Ltd | Financial services | 2019 |
| Pharmadrug Ltd | Health & social care | 2022 |
| Philip Groves Holdings Ltd | Real estate | 2018 |
| Philip Groves Partnership LLP | | 2018 |
| Phillips Fabrications Ltd | Manufacturing | 2018 |
| Phillips Family Holdings Ltd | Real estate | 2017 |
| Phillips Family Partnership LLP | | 2017 |
| Phoenix Counselling and Therapy Services CIC | Health & social care | 2023 |
| Phoenix Fitness (BTS) Limited | Arts & recreation | 2017 |
| Phoenix Nitrogen Services (UK) Limited | Professional & scientific | 2026 |
| Phoenix Property Millennium Limited | Real estate | 2020 |
| Phusion IM Limited | Information & communication | 1992 |
| PI Tech Services Ltd | Manufacturing | 2023 |
| Pilckem Properties LLP | | 2016 |
| Pink Opal Ltd | Real estate | 2016 |
| Pinnacle Training (NE) Limited | Education | 2014 |
| Pinnacle Training Wearside Limited | Education | 2019 |
| Pinnaclean Ltd | Administrative & support | 2026 |
| Pioneer Mouldings Limited | Manufacturing | 2016 |
| Pitman Contractors Ltd | Construction | 2026 |
| Pitsligo Properties Ltd | Real estate | 2021 |
| Pitsligo Properties Partnership LLP | | 2021 |
| PJD Properties Ltd. | Real estate | 2018 |
| PJT Finance Limited | Financial services | 2002 |
| PJW Logistics Ltd | Transport & logistics | 2018 |
| Plane Tree Farm Services Limited | Agriculture & fishing | 2024 |
| Plas-Serv Limited | Wholesale & retail | 2023 |