| Redline Express Limited | Transport & logistics | 2016 |
| Refresh Bidco Ltd | Financial services | 2022 |
| Refresh Holdco Ltd | Financial services | 2022 |
| Rehabilitate Youth Ireland C.I.C. | Administrative & support | 2020 |
| Reids Newtownabbey Limited | Wholesale & retail | 2019 |
| Renrut Consulting Limited | Professional & scientific | 2026 |
| Rent the Riviera Ltd | Hospitality | 2021 |
| Renu Property Ltd | Construction | 2020 |
| Research Peptides NI Limited | Wholesale & retail | 2025 |
| Resourceable Limited | Professional & scientific | 2011 |
| Revelation Accountants Ltd | Professional & scientific | 2020 |
| Revitalise Health and Performance Ltd | Arts & recreation | 2026 |
| Reviva X Labs Limited | Professional & scientific | 2026 |
| Rgmni Consultancy Ltd | Professional & scientific | 2025 |
| Richard Vance Cars Ltd | Wholesale & retail | 2021 |
| Richmond Subs Ltd | Hospitality | 2017 |
| Right on Promotions Limited | Wholesale & retail | 2020 |
| Rightclick-It Ltd | Information & communication | 2006 |
| Rise Performance Ltd | Arts & recreation | 2017 |
| Riverside Manor Management Antrim Limited | Real estate | 2016 |
| RKC Cars Ltd | Wholesale & retail | 2023 |
| RKG Rigging Ltd | Manufacturing | 2025 |
| RL Exports Limited | Transport & logistics | 2025 |
| RL Hair and Beauty Limited | Other services | 2017 |
| RLO Ltd | Construction | 2025 |
| RM Financial Consultants Ltd | Financial services | 2018 |
| RMD Property Management Services Ltd | Real estate | 2022 |
| RN Restaurant Ltd | Hospitality | 2020 |
| Rnnng Ltd | Arts & recreation | 2023 |
| Road Plant Ltd | Construction | 2024 |
| Roadmix Limited | Extraterritorial | 1978 |
| Robert J Stewart Ltd | Wholesale & retail | 2024 |
| Robert Neill Autos Limited | Wholesale & retail | 2025 |
| Robinson Quarry Masters Limited | Mining & quarrying | 1973 |
| Rocklyn Engineering Limited | Manufacturing | 1997 |
| Rockmount Vehicle Maintenance Limited | Wholesale & retail | 2010 |
| Rocprop 1 Limited | Construction | 2020 |
| Rocprop Limited | Construction | 2019 |
| Rodgers Holdings Ltd | Financial services | 2017 |
| Rodgers Property Investments Limited | Real estate | 2025 |
| Roisin Kelly Consulting Ltd | Professional & scientific | 2025 |
| Rosaleen Properties Ltd | Real estate | 2022 |
| Roshco Ltd | Other services | 2019 |
| Roslyn Aesthetics + Laser Ltd. | Health & social care | 2014 |
| Ross Bloodstock Ltd | Agriculture & fishing | 2011 |
| Rosseau Ltd | Professional & scientific | 2017 |
| RPC Consultancy Ltd | Administrative & support | 2013 |
| RSA NI Ltd | Mining & quarrying | 2026 |
| RSA NI Properties Ltd | Real estate | 2026 |
| Rtca Holdings Ltd | Administrative & support | 2025 |
| RTU Developments Limited | Construction | 2016 |
| RTU Limited | Manufacturing | 2014 |
| Ruby Properties (NI) Ltd | Real estate | 2012 |
| Rumbles Autism Community Interest Company | Administrative & support | 2024 |
| Rumours (N.I.) LLP | | 2016 |
| Ryan Burnison Limited | Administrative & support | 2025 |
| Rylor Ltd | Real estate | 2022 |
| S & E Couriers Limited | Transport & logistics | 2018 |
| S Mcauley Dental Ltd | Health & social care | 2025 |
| S W Marsden Ltd | Transport & logistics | 2020 |
| S. G. Murphy & Co. Ltd | Professional & scientific | 2011 |
| S. S. Logan & SON Limited | Wholesale & retail | 1974 |
| S.M. Components Ltd | Manufacturing | 2012 |
| S.W.I.M. Belfast Ltd | Arts & recreation | 2025 |
| S.W.I.M. Carryduff Ltd. | Education | 2023 |
| S.W.I.M. Lisburn Ltd | Education | 2026 |
| S75 Events Ltd | Information & communication | 2019 |
| Saebour Defence Ltd | Administrative & support | 2020 |
| Safe GAS (N.I.) Limited | Construction | 2012 |
| Safety Health & Environmental Services (NI) Ltd | Administrative & support | 2018 |
| SAL Supplies Ltd | Wholesale & retail | 2025 |
| Salt Clinic Ltd | Health & social care | 2025 |
| Saltbox Property Ltd | Real estate | 2018 |
| Sammys C Ltd | Households | 2026 |
| Samsa Health Limited | Information & communication | 2025 |
| Samuel Johnston Limited | Wholesale & retail | 1986 |
| Samuel Kirk (Builders Merchants) Limited | Wholesale & retail | 1973 |
| Saolas Investment Limited | Wholesale & retail | 2025 |
| Sapphire Romanian Opportunity Fund | | 2009 |
| Sarcon (NO.224) Limited | Construction | 2006 |
| SB and ASH Limited | Health & social care | 2023 |
| SBS Food and Drink Ltd | Wholesale & retail | 2020 |
| Scalp Micro-Pigmentation NI Limited | Professional & scientific | 2017 |
| Scan Alarms and Security Systems (U.K.) Limited | Other services | 1982 |
| Scan Alarms Limited | Other services | 1988 |
| Scanlon Print (Belfast) Limited | Manufacturing | 2007 |
| Scarlett Rose Ltd | Wholesale & retail | 2021 |
| Science and Art Explorers Ltd | Mining & quarrying | 2024 |
| Sciencenote Ltd | Education | 2026 |
| Scobie and Junior (Ireland) Limited | | 1978 |
| Scout Index Ltd | Arts & recreation | 2025 |
| Scribe Sports Limited | Wholesale & retail | 2018 |
| Scuto Ltd | Information & communication | 2012 |
| Seacoast Investments Ltd | Professional & scientific | 2015 |
| Seaport Estates Ltd | Real estate | 2026 |
| Second Chance Ballet Ltd | Education | 2022 |
| Second Collective Belfast CIC | Administrative & support | 2021 |
| Secret Stash Yarn Shop Limited | Wholesale & retail | 2024 |
| SEN Behaviour Support Ltd | Education | 2025 |
| Sentinel SEC NI Ltd | Administrative & support | 2025 |