| Owen & Palmer Limited | Construction | 1973 |
| Owen Paul-Smoth Ltd | Transport & logistics | 2025 |
| Oxford Analytics Group Ltd | Professional & scientific | 2015 |
| Oxford House Bournemouth Limited | Construction | 2014 |
| P & E Retail Bangor Ltd | Wholesale & retail | 2015 |
| P Banham Building Contractor Ltd. | Construction | 2007 |
| P J Coulter Joinery Ltd | Construction | 2021 |
| P&K Timber Frame Ltd | Construction | 2022 |
| P&L Plumbing & Heating (NI) Ltd | Construction | 2007 |
| P&Lg (Bangor) Limited | Hospitality | 2014 |
| P.C. Electrics Ltd | Construction | 2014 |
| P.F. Howell (Holdings) Limited | Professional & scientific | 2021 |
| P.F. Howell Limited | Wholesale & retail | 2000 |
| P.F. Howell Properties Limited | Real estate | 2025 |
| Paimar Ltd | Hospitality | 2025 |
| Pangolin Rare Books Ltd | Extraterritorial | 2024 |
| Panikclothingshop Limited | Wholesale & retail | 2025 |
| Pant YR Ardd Ltd | Hospitality | 2021 |
| Papas Mineral Company Ltd | Manufacturing | 2015 |
| Paradise Adventures Ltd | Arts & recreation | 2021 |
| Paragon Fire Protection (North Wales) Ltd | Construction | 2025 |
| Paragon Red Limited | Health & social care | 2023 |
| Parc Coed Moch CIC | Agriculture & fishing | 2022 |
| Parcel & Package Post Ltd | Transport & logistics | 2019 |
| Park Avenue Mews (Belfast) Limited | Households | 2010 |
| Park Pedal C.I.C. | Arts & recreation | 2026 |
| Park Road Developments (NW) Ltd | Construction | 2021 |
| Parkelife Limited | Education | 2019 |
| Parklands Cafe Ltd | Hospitality | 2015 |
| Partneriaeth Maesgeirchen Partnership | Other services | 2005 |
| Partneriaeth Rhostir Gogledd Cymru CBC | Other services | 2019 |
| Patient MED Healthcare Limited | Health & social care | 2022 |
| Patrick Roche Limited | Construction | 2012 |
| Patrick's Auto Limited | Wholesale & retail | 2021 |
| Paubar Limited | Real estate | 2025 |
| Paul Edwards Electrical Limited | Construction | 2025 |
| Pawlings Insulation and Supplies Limited | Construction | 1985 |
| PBP Developments Ltd | Real estate | 2017 |
| PC Audio Broadcast Ltd | Manufacturing | 2025 |
| PCO Davies Limited | Construction | 2010 |
| Pdlls Holdings Limited | Financial services | 2025 |
| PE (Mount Carmel) Limited | Construction | 2016 |
| Peak XV Consulting Ltd | Administrative & support | 2011 |
| Pebbl Ltd | Information & communication | 2025 |
| Pebble Ecommerce Consulting Ltd | Information & communication | 2024 |
| Pebbles & IVY Ltd | Real estate | 2021 |
| Pegasus Couriers Limited | Transport & logistics | 2022 |
| PELICANS33 Limited | Hospitality | 2024 |
| Pembridge Mews Residents Limited | Extraterritorial | 1988 |
| Pembrooke Apartments Limited | Extraterritorial | 1981 |
| Penhower Bach CYF | Hospitality | 2021 |
| Penmon Limited | Real estate | 2012 |
| Penmon Nasal Products Ltd | Manufacturing | 2023 |
| Penmon Nasal Services Ltd | Health & social care | 2023 |
| Penningtons Packaging Limited | Wholesale & retail | 2006 |
| Penny Smyth Estates Limited | Real estate | 2014 |
| Penrhyn Energy Limited | Energy | 2013 |
| Penrhyn Hostel Limited | Hospitality | 2014 |
| Pentagon Services (N.I.) Ltd | Transport & logistics | 2017 |
| Penybryn Outdoor Learning CIC | Education | 2022 |
| Perdix Consulting Ltd | Professional & scientific | 2018 |
| Pesda Press Limited | Information & communication | 2002 |
| Pet & Beauty Onilne Ltd | Wholesale & retail | 2025 |
| Peter Bennett Photography Ltd | Professional & scientific | 2022 |
| Peter Dornan & Company Limited | Professional & scientific | 2012 |
| Petrenol Limited | Mining & quarrying | 2005 |
| Petroclays Materials Ltd | Professional & scientific | 2010 |
| Pfnewco Limited | Financial services | 2022 |
| PGE Limited | Real estate | 2015 |
| PGK Consultancy Services Ltd | Professional & scientific | 2021 |
| PH Brickwork and Groundworks Limited | Construction | 2023 |
| Phantom Communications Ltd | Construction | 2021 |
| Pharmassist Training Limited | Professional & scientific | 2024 |
| Phat Bastrd Burger Ltd | Hospitality | 2025 |
| Philip Petersen Limited | Wholesale & retail | 1955 |
| Phipps Holdings Limited | Financial services | 2024 |
| Phixlab Ltd | Wholesale & retail | 2026 |
| Phoenix Industrial Training Ltd | Education | 2016 |
| Phonerepairsshop Limited | Other services | 2025 |
| Phones Repair Center Ltd | Wholesale & retail | 2025 |
| Phpbelfast Limited | Information & communication | 2015 |
| PI Business Holdings Ltd | Financial services | 2019 |
| PIA Rossini Ltd | Manufacturing | 1997 |
| Pianoforall Academy Limited | Education | 2025 |
| Picking Energy Ltd | Professional & scientific | 2025 |
| Picnics and Cakes Ltd | Wholesale & retail | 2016 |
| PIG Regen Limited | Professional & scientific | 2007 |
| Pine Tree House Management Co. Ltd | Extraterritorial | 2000 |
| Pinkertons (NI) Limited | Real estate | 2012 |
| Pinksalts Wholesale Ltd | Manufacturing | 2025 |
| Pinnacle Fit Pro Limited | Arts & recreation | 2025 |
| Pip-Bn Lodgings Ltd | Hospitality | 2021 |
| Pirrie Belfast Limited | Construction | 2020 |
| Pitched Brothers Ltd | Arts & recreation | 2023 |
| Pizza Eclipse Ltd | Hospitality | 2025 |
| PKL Piping Services Limited | Administrative & support | 2013 |
| PLANT3D Ltd | Wholesale & retail | 2024 |
| Plas Bowman Management Company Limited | Households | 2007 |
| Plasma Media Ltd. | Information & communication | 2010 |
| Play City Limited | Arts & recreation | 2013 |