| OR Training & Personal Development Ltd | Education | 2013 |
| Oram Properties Limited | Real estate | 2014 |
| Orbane Construction Limited | Construction | 2023 |
| Orchard BIM Solutions Ltd | Professional & scientific | 2023 |
| Orchard Cardiac Services Ltd | Health & social care | 2024 |
| Orchard County Enterprises Limited | Wholesale & retail | 2005 |
| Orchard DRY Ice Blasting Ltd | Administrative & support | 2025 |
| Orchard Eyecare Limited | Public administration | 2020 |
| Orchard Formwork Limited | Construction | 2015 |
| Orchard Fresh Foods Limited | Manufacturing | 2001 |
| Orchard Fuels Ltd | Wholesale & retail | 2019 |
| Orchard Kitchens and Bedrooms Limited | Manufacturing | 2011 |
| Orchard Motor Hire Ltd | Wholesale & retail | 2024 |
| Orchard Motors Ltd | Wholesale & retail | 2017 |
| Orchard Organics (NI) Limited | Agriculture & fishing | 2001 |
| Orchard Power Washing Limited | Administrative & support | 2025 |
| Orchard Refrigeration Limited | Manufacturing | 1997 |
| Orchard Veterinary Centre (Armagh) Limited | Professional & scientific | 2014 |
| Osrn Ltd | Hospitality | 2025 |
| OTM Automotive Ltd | Wholesale & retail | 2025 |
| OTW Equip Limited | Administrative & support | 2017 |
| Outbounders Ltd | Wholesale & retail | 2025 |
| Outhalf AI Limited | Information & communication | 2025 |
| Owens Brothers Transport Limited | Transport & logistics | 2020 |
| Owens Transport Limited | Transport & logistics | 2014 |
| P & G Tippers Limited | Wholesale & retail | 2015 |
| P & M Retail Limited | Real estate | 2010 |
| P & T Machinery Ltd | Mining & quarrying | 2003 |
| P Curry Electrical Ltd | Construction | 2026 |
| P Kennedy Properties Ltd | Real estate | 2025 |
| P Mckeever Contracts Limited | Construction | 2020 |
| P Mckenna Transport Ltd | Transport & logistics | 2009 |
| P&D Invest Ltd | Real estate | 2025 |
| P.I.T Farms Ltd | Agriculture & fishing | 2019 |
| P2P Customs Ltd | Transport & logistics | 2021 |
| P4P Cards Ltd | Wholesale & retail | 2025 |
| PAL Takeaway Limited | Hospitality | 2025 |
| Pallet Stock Warehouse Ltd | Wholesale & retail | 2022 |
| Parkland Restaurant and Catering Ltd | Hospitality | 2023 |
| Patian Ltd | Hospitality | 2025 |
| Patricia's Village Ltd | Wholesale & retail | 2012 |
| Patterson Poultry Ltd | Agriculture & fishing | 2015 |
| Pattison Picture Cars Ltd | Information & communication | 2022 |
| Patton Property Group Ltd | Real estate | 2025 |
| Paul Maguire Ltd | Construction | 2018 |
| PB Farms Limited | Agriculture & fishing | 2026 |
| Pearl Boutique NI Ltd | Wholesale & retail | 2023 |
| Perfect Solutions Ireland Ltd | Administrative & support | 2020 |
| Petdomain Ltd | Wholesale & retail | 2021 |
| Peter Allen Contracts Limited | Construction | 2024 |
| Peter Allen Developments Limited | Real estate | 2025 |
| Peter Allen Property Limited | Real estate | 2024 |
| Peter Bennett Motorsport Ltd | Wholesale & retail | 2021 |
| Peter Clarke 171 Ltd | Wholesale & retail | 2024 |
| Peter Mcmahon & Associates Ltd | Administrative & support | 2003 |
| Petrasia Ltd | Other services | 2021 |
| PG Car Hire Ltd | Administrative & support | 2023 |
| PG Crash Repair Ltd | Wholesale & retail | 2024 |
| PG Ecom Ltd | Wholesale & retail | 2025 |
| Philip Kennedy Engineering Limited | Professional & scientific | 2017 |
| Philip White Limited | Wholesale & retail | 1988 |
| Philip White Tyres (Holdings) Limited | Professional & scientific | 2023 |
| Philip White Tyres Limited | Wholesale & retail | 1986 |
| Phoenix Distribution Ltd | Transport & logistics | 2022 |
| Photon Addicts Ltd | Administrative & support | 2025 |
| Piggy Performance Limited | Wholesale & retail | 2024 |
| Pinewoods Lodge Ltd | Wholesale & retail | 2026 |
| Pinkerton European Ltd | Transport & logistics | 2020 |
| Pinkertons Ltd | Manufacturing | 2011 |
| Pinnacle Construction & Design Ltd | Administrative & support | 2018 |
| Pittstop (Armagh) | Wholesale & retail | 2003 |
| PJ Fuels Ltd | Wholesale & retail | 2022 |
| PJT Bricklaying Ltd | Construction | 2025 |
| PL Haulage Ltd | Transport & logistics | 2018 |
| Planning and Development Enterprise Services Ltd | Professional & scientific | 2017 |
| Plaspro Limited | Manufacturing | 2012 |
| Plastic Trader Ltd | Wholesale & retail | 2018 |
| Player Development Academy NI Ltd | Education | 2026 |
| PLG19 Ltd | Wholesale & retail | 2020 |
| PM QS Consultancy Ltd | Professional & scientific | 2025 |
| Pmac Properties Ltd | Real estate | 2023 |
| PMC Consulting (IRE) Ltd | Construction | 2007 |
| Pmcg Haulage Ltd | Transport & logistics | 2024 |
| PMG Contracts Limited | Construction | 2022 |
| Pmlpoultry Ltd | Agriculture & fishing | 2026 |
| PMQ Bespoke Fitout Limited | Manufacturing | 2025 |
| PMR Developments Limited | Construction | 2016 |
| PNB Plumbing Limited | Construction | 2019 |
| POC NI. Distribution Ltd | Wholesale & retail | 2014 |
| Polymer Resource Limited | Water & waste | 2017 |
| Polymer Resource Management Limited | Water & waste | 2017 |
| Porcelain and Stone (NI) Limited | Manufacturing | 2024 |
| Portbannis AM 10 Ltd | Real estate | 2026 |
| Portbannis AM 11 Ltd | Real estate | 2026 |
| Portbannis AM 4 Ltd | Real estate | 2022 |
| Portbannis Ltd | Real estate | 2014 |
| Portnelligan Farms Ltd | Agriculture & fishing | 2023 |
| Portours Limited | Real estate | 2001 |
| Postcard Company Limited - the | Manufacturing | 1996 |
| Powertech Refrigeration Ltd | Construction | 2004 |