| Railway Food Limited | Hospitality | 2018 |
| Rainboard Properties L.P. | | 2015 |
| Rajas Belfast Ltd | Hospitality | 2019 |
| Rami Partners Ltd | Wholesale & retail | 2021 |
| Ramp Property Services Ltd | Real estate | 2025 |
| Rane Digital Marketing Agency Ltd | Information & communication | 2018 |
| Rane Group Ltd | Information & communication | 2017 |
| Rapid Developments (NI) Limited | Construction | 2012 |
| Rapid Homes Ireland Limited | Wholesale & retail | 2024 |
| Rapid Property Holdings Ltd | Real estate | 2025 |
| Rapid Tyre Distribution Ltd | Wholesale & retail | 2025 |
| Rapture Teenage Disco Ltd | Arts & recreation | 2011 |
| Rashida & Noah Designs Ltd | Wholesale & retail | 2020 |
| Rathbane Group Services Limited | Professional & scientific | 2019 |
| Rathbane Investments Limited | Real estate | 2019 |
| Rathdallan Management Limited | Households | 2007 |
| Rathfriland Courtyard Limited | Households | 2003 |
| Rathkeelan Properties Ltd | Financial services | 2020 |
| Rathlin Towers Limited | Real estate | 2014 |
| Rathmore Close Management Ltd | Households | 2017 |
| Rathmore Close Phase II Ltd | Households | 2024 |
| Rathmoyle Limited | Real estate | 2019 |
| Rathmullen Properties Limited | Households | 2018 |
| Rathvilla Developments Limited | Construction | 2019 |
| Raven Plant Hire Limited | Mining & quarrying | 2013 |
| Raven Tipper Hire Ltd | Transport & logistics | 2019 |
| Ravens Holdings Ltd | Real estate | 2021 |
| Ravensdale Indoor Living Limited | Wholesale & retail | 2002 |
| Raynard Networks L.P. | | 2015 |
| RB & AK Autos Limited | Wholesale & retail | 2024 |
| RB Enterprise Solutions Ltd | Professional & scientific | 2016 |
| RB Timberworks Ltd | Manufacturing | 2025 |
| Rbon (N.I.) Limited | Real estate | 2023 |
| RBQ Holding Limited | Financial services | 2020 |
| Rcfa Ltd | Professional & scientific | 2026 |
| RCL Tyre Wholesale Ltd | Wholesale & retail | 2019 |
| RCR Communications Limited | Information & communication | 2009 |
| RCS Support Services Ltd | Administrative & support | 2022 |
| RD Safety Ltd | Professional & scientific | 2024 |
| Rd-Redistribute Limited | Education | 2025 |
| RDG Recovery Ltd | Transport & logistics | 2019 |
| Rdni Ltd | Wholesale & retail | 2022 |
| Re-Eng Limited | Manufacturing | 2012 |
| Re-Gen Robotics Limited | Water & waste | 2018 |
| Re-Gen Studios Ltd | Health & social care | 2023 |
| REA Agencies Limited | Wholesale & retail | 1986 |
| REA Close Management Company Ltd. | Real estate | 2019 |
| Real Scents Ltd | Manufacturing | 2025 |
| Realqa Holding Ltd | Information & communication | 2024 |
| Reavey Financial Services Ltd | Financial services | 2017 |
| Reaw Services Ltd | Construction | 2024 |
| Rebct Ltd | Health & social care | 2020 |
| Rebel Events Ltd | Administrative & support | 2017 |
| Rebelbio Limited | Professional & scientific | 2018 |
| Rece Management Ltd | Professional & scientific | 2014 |
| Recoper Ltd | Wholesale & retail | 2019 |
| RECOVER8 Mobility Ltd | Wholesale & retail | 2020 |
| Recycle (N.I.) Ltd | Water & waste | 2019 |
| Recycled Aggregates Ireland Limited | Extraterritorial | 2024 |
| Red Box Plans Ltd | Transport & logistics | 2025 |
| Red Box Voip Ltd | Information & communication | 2023 |
| Red Branch Bushcraft CIC | Education | 2023 |
| Red Branch Security Services Ltd | Administrative & support | 2023 |
| Red Branch Technologies Ltd | Information & communication | 2021 |
| Red Meat Design Limited | Professional & scientific | 2025 |
| Redcliff Enterprises L.P. | | 2015 |
| Redvale Consultancy Ltd | Construction | 2011 |
| Reeva Boutique Ltd | Wholesale & retail | 2021 |
| Reexcel Online Ltd | Professional & scientific | 2023 |
| Reformation Tours Limited | Administrative & support | 2023 |
| Refresh Financial Services Ltd | Financial services | 2011 |
| Refutoo Community Interest Company | Education | 2016 |
| Regen Trailer Hire Limited | Manufacturing | 2019 |
| Regen Waste Holdings Limited | Professional & scientific | 2019 |
| Regen Waste Limited | Manufacturing | 2002 |
| Regen WTE Limited | Manufacturing | 2012 |
| Regika Holding LP | | 2018 |
| Regintel UK Limited | Professional & scientific | 2012 |
| Regnum Renewables Developments NI Limited | Energy | 2023 |
| Reic Holdings Limited | Information & communication | 2026 |
| Reid Holdings Limited | Professional & scientific | 2007 |
| Reid's Care Limited | Health & social care | 2017 |
| Rejuvenate (NI) Ltd | Arts & recreation | 2014 |
| Reliance Civil Engineering Solutions Ltd | Construction | 2019 |
| Reliance Precision NI Limited | Extraterritorial | 2020 |
| Reline U.V Distribution Ltd | Administrative & support | 2023 |
| Reman Solutions Ltd | Manufacturing | 2018 |
| Remap IRE Ltd | Real estate | 2017 |
| REN Fuel Ltd | Energy | 2012 |
| Renew Aesthetic Clinic Limited | Health & social care | 2018 |
| Renewell Water UK Ltd | Other services | 2012 |
| Rental-Mate Limited | Real estate | 2018 |
| Repass Bricklaying Services Ltd | Construction | 2019 |
| Repromed Ireland | Health & social care | 2010 |
| Requiem Coffee Limited | Manufacturing | 2025 |
| Resin Bound Ireland Ltd | Construction | 2024 |
| Resolute Civils UK Limited | Construction | 2024 |
| Resonate Testing Ltd | Professional & scientific | 2015 |
| Restore Property Claims Limited | Financial services | 2015 |
| Retail NOW Ltd | Wholesale & retail | 2022 |