| Pivotal Maintenance & Construction Ltd | Construction | 2018 |
| PJK Aviation Ltd | Manufacturing | 2016 |
| PJM Services (N.I.) Ltd | Administrative & support | 2024 |
| PK Freight Ireland Ltd | Transport & logistics | 2015 |
| Planet Ecuador Ltd | Wholesale & retail | 2022 |
| Play Make-Believe Ltd | Arts & recreation | 2022 |
| Pmac Inspection (Antrim) Ltd | Other services | 2021 |
| PMG Specialist Cars NI Ltd | Wholesale & retail | 2024 |
| Polar Telecoms Ltd | Information & communication | 2021 |
| Poli Productions Ltd | Construction | 2018 |
| Polivision Ltd | Information & communication | 2024 |
| Pollock Lifts Limited | Manufacturing | 1985 |
| Pollock Public Access Lifts Limited | Construction | 2018 |
| Portsmouth Properties Management Ltd | Real estate | 2023 |
| Positive Carrickfergus CIC | Health & social care | 2020 |
| Positive Carrickfergus Group Limited | Arts & recreation | 2026 |
| Postmasters Walk Management Company Limited | Households | 2018 |
| Potters Snooker Club Ltd | Arts & recreation | 2014 |
| Powerful Cloud Business Ltd | Wholesale & retail | 2025 |
| Precise Proposals Ltd | Professional & scientific | 2013 |
| Prider UK Limited | Wholesale & retail | 2023 |
| Princetown Apartments Management Limited | Households | 2006 |
| Proteus Marine Ltd | Professional & scientific | 2025 |
| Proto-Cal Laboratories Limited | | 1990 |
| Pulse and Pace CIC | Education | 2026 |
| Pushing INK (Carrickfergus) Ltd | Other services | 2014 |
| Púca Pictures Ltd | Information & communication | 2021 |
| QH Construction Ltd | Construction | 2011 |
| QMS Insight Limited | Information & communication | 2014 |
| Quality Guaranteed Limited | Professional & scientific | 2022 |
| Quarter House Coffee (N.I.) Ltd | Hospitality | 2025 |
| R Morgan Engineering Ltd | Manufacturing | 2018 |
| R&A Aviation Services Ltd | Manufacturing | 2018 |
| R&E-Company Ltd | Manufacturing | 2022 |
| Rabbit and the FOX Films Limited | Information & communication | 2015 |
| RAG & Bone Fuel Ltd | Manufacturing | 2025 |
| Raidmed Ltd | Manufacturing | 2022 |
| Railway Halt Management Committee Limited | Households | 2004 |
| Raphael's Silverwings Investment Private Ltd | Financial services | 2025 |
| Rastyove Ltd | Wholesale & retail | 2025 |
| Rathmore Road Management Company Limited | Extraterritorial | 2007 |
| Rathunas Logistics Limited | Wholesale & retail | 2019 |
| Raughlan Meadows Management Limited | Households | 2007 |
| Ravenhill Funeral Services Limited | Extraterritorial | 1977 |
| Ravenhill Lane Management Company Limited | Households | 2001 |
| Ravenscroft Apartments (Carrickfergus) Limited | Households | 1987 |
| RB Electrical Services Ltd | Construction | 2021 |
| RD Investigations Ltd | Administrative & support | 2009 |
| RDG Construction & Surveying Ltd | Construction | 2018 |
| REA Estates (NI) Limited | Administrative & support | 2003 |
| Ready Steady School Ltd | Education | 2025 |
| Realize Ltd | Manufacturing | 2025 |
| Reavey & Company Ltd | Professional & scientific | 2011 |
| Reavey & Company Solicitors LLP | | 2023 |
| Rebecca Cooper Hair Ltd | Other services | 2022 |
| Rebecca's Carrickfergus Limited | Other services | 2020 |
| Rectory Fields Services Limited | Households | 2004 |
| Red Power Generators Limited | Wholesale & retail | 2010 |
| Redacted Independent Bottlers Limited | Wholesale & retail | 2023 |
| Redpath Solar Energy Solutions Ltd | Professional & scientific | 2016 |
| Redrow Brickworks Limited | Construction | 2018 |
| Regan Financial Limited | Financial services | 2009 |
| Reicas Ltd | Hospitality | 2024 |
| Reinol Ireland Ltd | Wholesale & retail | 2022 |
| Reliable Claims Solutions Limited | Financial services | 2000 |
| Reliable Vehicle Solutions Limited | Administrative & support | 2012 |
| Restart Racing Btcc Limited | Arts & recreation | 2022 |
| Restore IT Ltd | Information & communication | 2016 |
| Result Carrickfergus Limited | Arts & recreation | 2024 |
| Rhanbuoy Mews Management Company Ltd | Households | 2013 |
| Rhino Property Development Ltd | | 2004 |
| Richard Curry Cars LLP | | 2014 |
| Riot & Noble Ltd | Other services | 2021 |
| Riot & Retail Ltd | Wholesale & retail | 2021 |
| Riviera Bathroom and Tiles Ltd | Wholesale & retail | 2024 |
| RJ Forwarding Ltd | Transport & logistics | 2023 |
| RJM Infinity Ltd | Wholesale & retail | 2026 |
| RL Lifts Ltd | Manufacturing | 2025 |
| RM Advertising Ltd | Professional & scientific | 2022 |
| RMB Farms Limited | Agriculture & fishing | 2022 |
| RMN Billposting Services Ltd | Professional & scientific | 2019 |
| RN Flexi Ltd | Health & social care | 2023 |
| Roadside Assistance (N.I.) Ltd | Wholesale & retail | 2025 |
| Robinson Engineering (N.I.) Ltd | Manufacturing | 2020 |
| Robinson's Shoemakers Limited | Wholesale & retail | 2007 |
| Rocblast Ltd | Mining & quarrying | 2007 |
| Rockdene Apartment Management Company Limited | Households | 2021 |
| Rockview Property Ltd | Real estate | 2026 |
| Roeshill Management Company Limited | Households | 2005 |
| Roger Torrens Ltd | Other services | 2023 |
| Rogueink Ltd | Arts & recreation | 2023 |
| Roof Training (NI) Ltd | Other services | 2009 |
| Rosganna Properties Ltd | Financial services | 2001 |
| Rowan James Real Estate Ltd | Real estate | 2026 |
| Rowan Software Engineering Ltd | Information & communication | 2015 |
| RP Distributors Ltd | Professional & scientific | 2026 |
| RPD Investments Limited | Construction | 2022 |
| RR Aerotech Ltd | Manufacturing | 2014 |
| RS Power Networks Ltd | Construction | 2025 |
| RS Repair Ltd | Manufacturing | 2025 |