| RPH Trading Limited | Wholesale & retail | 2020 |
| RPR Contracts Limited | Construction | 2007 |
| RPR Investments Limited | Real estate | 2021 |
| RTF Poultry Holdings Ltd | Financial services | 2026 |
| RTF Poultry Limited | Agriculture & fishing | 2012 |
| RTM Mortgage Services Ltd | Financial services | 2012 |
| Rubber & Plastic Products (NI) Limited | Manufacturing | 1990 |
| Rudmix Concrete Batching Systems Ltd | Manufacturing | 2013 |
| Ruth Raising UP the Hurting Limited | Health & social care | 2013 |
| Ryan's Global Ltd | Administrative & support | 2022 |
| Ryder Nails Shop Ltd | Other services | 2025 |
| Ryzer Medical Ltd | Health & social care | 2026 |
| S & G Transport (NI) Ltd | Transport & logistics | 2010 |
| S & I Properties Limited | Construction | 2008 |
| S & S Property Holdings (N.I.) Ltd | Real estate | 2022 |
| S & S Property MGT NI Limited | Real estate | 2021 |
| S & T Poultry Ltd | Agriculture & fishing | 2016 |
| S Cullen Plumbing Ltd | Construction | 2026 |
| S E Heavy Haul (NI) Ltd | Transport & logistics | 2020 |
| S Mccrory & Company Ltd | Professional & scientific | 2013 |
| S Mullin Contracts Ltd | Construction | 2019 |
| S Oliver Transport Limited | Wholesale & retail | 2022 |
| S&D Farms Ltd | Agriculture & fishing | 2021 |
| S&G Transport International Ltd | Transport & logistics | 2025 |
| S. E. Marshall & Co. Limited | Agriculture & fishing | 2003 |
| S. Jordan Cabins & Concrete Equipment Ltd | Manufacturing | 2024 |
| S.A. Kennedy Engineering Limited | Manufacturing | 2015 |
| S.Morris Holdings Ltd | Financial services | 2024 |
| S4S Developments Ltd | Construction | 2021 |
| S4S Holdings Ltd | Construction | 2016 |
| Safeguard Accidents Ltd | Financial services | 2024 |
| Safescreen Occupation Health Ltd | Health & social care | 2026 |
| Salesmachinex.Com Ltd | Information & communication | 2003 |
| Saltmarine Cars Ltd | Wholesale & retail | 2026 |
| Saltmarine Ltd | Wholesale & retail | 2026 |
| Sandale Developments Limited | Construction | 2007 |
| Sandark Engineering Ltd | Manufacturing | 2022 |
| Sandholes Property Limited | Professional & scientific | 2004 |
| Sandwich Supreme Ltd | Manufacturing | 2005 |
| Sandymount Farms, Limited | Real estate | 1943 |
| Saona Sun Studio Ltd | Other services | 2022 |
| SAP Armagh Ltd | Financial services | 2020 |
| Sarajlo Limited | Health & social care | 2025 |
| Saran Property Ltd | Households | 2025 |
| Sauna Select Ltd | Wholesale & retail | 2024 |
| Sawel Holdings Limited | Financial services | 2019 |
| Sawgrass Substrates Limited | Agriculture & fishing | 2024 |
| Sawtech Ireland Limited | Manufacturing | 2004 |
| Sawyers Holdings Ltd | Financial services | 2019 |
| Sawyers Property Ltd | Administrative & support | 2019 |
| SBE Contracts Limited | Construction | 2023 |
| SBOD3 Ltd | Real estate | 2023 |
| SC Formwork Ltd | Construction | 2019 |
| Scafell Property Holdings Limited | Financial services | 2023 |
| Scalex Talent Solutions Ltd | Administrative & support | 2023 |
| Scapegallows Limited | Arts & recreation | 2015 |
| Scissors Direct Limited | Wholesale & retail | 1994 |
| SCK Business Solutions Ltd | Professional & scientific | 2025 |
| SCL Exhausts Ltd | Manufacturing | 2011 |
| SCM Systems Ltd | Wholesale & retail | 2023 |
| Scootabout Mobility Services Ltd | Wholesale & retail | 2021 |
| Scope Electrical Solutions Ltd | Construction | 2009 |
| Scott Power Washing Ltd | Administrative & support | 2026 |
| Screencore Ltd | Manufacturing | 2017 |
| Screening Solutions Ireland Ltd | Wholesale & retail | 2024 |
| Screenpod Design & Manufacturing Limited | Manufacturing | 2010 |
| Scsod Holdings Limited | Financial services | 2025 |
| SD Entertainment Ltd | Professional & scientific | 2015 |
| SD8 Promo Ltd | Professional & scientific | 2025 |
| Sdac Logistics Ltd | Transport & logistics | 2021 |
| SE3 Digital Limited | Information & communication | 2020 |
| Seal Ventures Limited | Financial services | 2019 |
| Seamless Sales (NI) Ltd | Professional & scientific | 2025 |
| Sean J Jordan Engineering Limited | Manufacturing | 1991 |
| Sean Nugent Engineering Limited | Manufacturing | 2003 |
| Sean Nugent Holdings Ltd | Financial services | 2021 |
| Sean Toner Mechanical Ltd | Construction | 2025 |
| Seba Veron Ltd | Financial services | 2022 |
| Seed Group Ltd | Financial services | 2023 |
| Seed Manchester Ltd | Hospitality | 2023 |
| Seed Salads Ltd | Hospitality | 2019 |
| Seine NET Limited | Agriculture & fishing | 2008 |
| Sentireal Limited | Information & communication | 2013 |
| Serc Consulting Limited | Information & communication | 2012 |
| SET Build NI Ltd | Construction | 2010 |
| Seth Ltd | Extraterritorial | 2013 |
| Seyloran FJC Property Ltd | Real estate | 2025 |
| Seyloran Ltd | Real estate | 2026 |
| Seyloran Properties Limited | Real estate | 2013 |
| Seyloran Steelworks Limited | Professional & scientific | 2022 |
| SFK Automotive Ltd | Wholesale & retail | 2025 |
| SGK 24 HR Recovery Ltd | Transport & logistics | 2016 |
| SH Thermo Limited | Transport & logistics | 2022 |
| Shan Interiors Ltd | Wholesale & retail | 2021 |
| Shankley Properties Limited | Real estate | 2006 |
| Sharpe Music Ltd | Wholesale & retail | 2011 |
| Shaun Owens Ltd | Wholesale & retail | 2025 |
| Shauna Kelly Interiors Ltd. | Professional & scientific | 2018 |
| Shazleah Ltd | Financial services | 2014 |
| Shedco - the Shed Company Ltd | Construction | 2021 |