| Rsms Enterprises Private Ltd | Hospitality | 2025 |
| RSN Spirits Group Ltd | Wholesale & retail | 2025 |
| Rtaelectrics Ltd | Construction | 2023 |
| Rumours Coffee House Ltd | Hospitality | 2021 |
| Rusty's Courier Ltd | Transport & logistics | 2025 |
| RVC Services Ltd | Professional & scientific | 2024 |
| Ryan Thomas Murray Contracting Ltd | Administrative & support | 2024 |
| Rzhgfh Ltd | Hospitality | 2024 |
| S.K.C. Music Limited | Administrative & support | 1982 |
| S.P.K. Logistics Ltd | Transport & logistics | 2000 |
| Safesip Limited | Professional & scientific | 2025 |
| Safety OFF Ltd | Information & communication | 2022 |
| Samurai Padel Co Ltd | Manufacturing | 2026 |
| Sanctuary Counselling Limited | Health & social care | 2024 |
| Sanctuary-By-The-Sea Ltd | Other services | 2011 |
| Sandra Pyper Property Management Ltd | Real estate | 2008 |
| Saormind Ltd | Health & social care | 2025 |
| Saphire Window Systems Limited | Extraterritorial | 1987 |
| Sasa Smith Limited | Wholesale & retail | 2025 |
| Savage Aviation Ltd | Manufacturing | 2016 |
| Savage Education Systems (N.I.) Ltd | Education | 2022 |
| Savage Martial Arts Academy Ltd | Education | 2026 |
| Savage Merchandise (N.I.) Ltd | Wholesale & retail | 2022 |
| SB- Raffos Limited | Hospitality | 2019 |
| SC Social Circle Limited | Professional & scientific | 2022 |
| Scanall Ltd | Manufacturing | 2018 |
| Scanmatix Limited | Information & communication | 2022 |
| SE Contracts Ltd | Construction | 2019 |
| Seagull Security Ltd | Administrative & support | 2026 |
| Sean Casey Ebooks Limited | Information & communication | 2021 |
| Sean Casey Mentoring Ltd | Administrative & support | 2026 |
| Sean Casey Property Ltd | Real estate | 2024 |
| Season Coffee Shop Ltd | Hospitality | 2025 |
| Securatek Ltd | Information & communication | 2007 |
| Seedability Limited | Agriculture & fishing | 2019 |
| Sensory DEN Services CIC | Health & social care | 2026 |
| Service Fitness Limited | Arts & recreation | 2024 |
| Seven Pensions Management Limited | Financial services | 2014 |
| Sevenfin Limited | Financial services | 2020 |
| Shampoodle (NI) Ltd | Wholesale & retail | 2012 |
| Shankill Funeral Services Limited | Extraterritorial | 1940 |
| Sherriff Protection Ltd | Administrative & support | 2018 |
| Shopping Friendly Space Ltd | Wholesale & retail | 2025 |
| Short Circuit Racing Promotions (Ireland) Limited | Arts & recreation | 2023 |
| Sidings (Ballynahinch) Management Company Limited - the | Households | 2003 |
| Signscript Ltd | Manufacturing | 2011 |
| Silver Apparel Limited | Wholesale & retail | 2020 |
| Silverwings by Shil Limited | Hospitality | 2026 |
| Simms Properties Ltd | Real estate | 2023 |
| SK Golf Ltd | Wholesale & retail | 2025 |
| SK Pizza Carrickfergus Limited | Hospitality | 2025 |
| SKC Gaming (N.I.) Ltd | Arts & recreation | 2015 |
| Sky Lane Engineering Ltd | Manufacturing | 2021 |
| Skybridge Technics Ltd | Manufacturing | 2026 |
| Skyline Contracts Limited | Construction | 2016 |
| Slate Sales Ireland Ltd | Construction | 2001 |
| Sloane Engineering Ltd | Manufacturing | 2019 |
| SLP Building Consultants Ltd | Construction | 2026 |
| Smart Zone (N.I.) Ltd | Wholesale & retail | 2021 |
| Smartfile Ltd | Professional & scientific | 2023 |
| SMX Holdings Limited | Information & communication | 2020 |
| SOF Engineering Limited | Professional & scientific | 2022 |
| Solar Fit Installations Ltd | Construction | 2019 |
| Solid Fabrications Limited | Manufacturing | 2009 |
| Somerset Furnishings (NI) Ltd | Wholesale & retail | 2009 |
| Sooperfit Ltd | Wholesale & retail | 2022 |
| Source HV Ltd | Professional & scientific | 2026 |
| South Lake Park Management Company Ltd | Households | 2023 |
| Sozo Good Antrim Road Ltd | Hospitality | 2015 |
| Sozo Good Jordanstown Ltd | Hospitality | 2013 |
| SP Harland Ltd | Hospitality | 2024 |
| Spare Time Apps Ltd | Information & communication | 2018 |
| Sparkle Clean Group Ltd | Households | 2025 |
| Spatial Simulations Ltd | Information & communication | 2023 |
| Special Brands Limited | Wholesale & retail | 2024 |
| Speed Consult Ltd | Administrative & support | 2025 |
| Sperrin Consultancy Services Ltd | Information & communication | 2024 |
| Spiers Electrical Ltd | Construction | 2019 |
| Spinners Gate Management Company Ltd | Households | 2017 |
| SPR Roofing Ltd | Construction | 2026 |
| Springsteen's Restaurants Limited | Hospitality | 2009 |
| Square Media Limited | Wholesale & retail | 2019 |
| SRD Property Ltd | Real estate | 2020 |
| SS Clothing Ltd | Wholesale & retail | 2026 |
| SS Controls Ltd | Professional & scientific | 2013 |
| ST Colmans Court Management Company Ltd | Households | 2009 |
| Stacey Mellon Ltd | Education | 2024 |
| Stacey's Golden Friends Ltd | Health & social care | 2026 |
| Starless Films Limited | Information & communication | 2019 |
| Starlex Tattoos Ltd | Arts & recreation | 2018 |
| Startoys Ltd | Wholesale & retail | 2021 |
| Static Source Ltd | Wholesale & retail | 2024 |
| Stellar Impact Ltd | Administrative & support | 2020 |
| Stephen Heddles Ltd | Wholesale & retail | 2006 |
| Stephen Patrick Smith Medical Consulting Ltd | Health & social care | 2019 |
| Stepstone Shoes Ltd | Wholesale & retail | 2025 |
| Steven Bridges Solutions Ltd | Manufacturing | 2018 |
| Stewart NI Enterprises Ltd | Information & communication | 2022 |
| Stitch&Store Ltd | Information & communication | 2021 |
| Stop Whitehead OIL Terminal Environmental Movement (Swotem) Ltd | Education | 2025 |