| Stewarts Solicitors | Professional & scientific | 2010 |
| Stick Proper Limited | Wholesale & retail | 2024 |
| Stockbridge Developments (N.I.) Limited | Construction | 2019 |
| Stocked Retail Ltd | Wholesale & retail | 2026 |
| Stockhill Brothers Limited | Manufacturing | 2025 |
| Stolaper Limited | Wholesale & retail | 2025 |
| Storm Timesu Limited | Wholesale & retail | 2024 |
| Stove Spare Parts Limited | Wholesale & retail | 2012 |
| Stovespareglass Ltd | Wholesale & retail | 2019 |
| Strangco Trading Limited | Manufacturing | 2016 |
| Strange Mind Limited | Wholesale & retail | 2023 |
| Strangford Consulting Limited | Professional & scientific | 2020 |
| Strangford Labs Ltd | Professional & scientific | 2020 |
| Strangford Lough Activity Centre Ltd | Arts & recreation | 2021 |
| Strangford Lough Boat Trips Ltd | Transport & logistics | 2021 |
| Strangford Lough Leisure Limited | Hospitality | 2013 |
| Strangford Lough Mussels Ltd | Wholesale & retail | 2015 |
| Strangford View Management Co. Ltd | Households | 2008 |
| Strathspey 7 Limited | Financial services | 2017 |
| Street Puppets NI Ltd | Education | 2025 |
| Strg Services Ltd | Professional & scientific | 2026 |
| Strides Day Opportunities Service Ltd | Health & social care | 2024 |
| Stronme Limited | Wholesale & retail | 2025 |
| Stuart Dubois Agri System Ltd | Wholesale & retail | 2025 |
| Stuart George Plumbing & Heating Ltd | Construction | 2026 |
| Suanmeitangderetail Ltd | Wholesale & retail | 2024 |
| Sucrograin Ltd | Wholesale & retail | 2025 |
| Suijun Limited | Wholesale & retail | 2023 |
| Suitable One Limited | Wholesale & retail | 2024 |
| Suitor Autofix Ltd | Other services | 2011 |
| Suitor Autos Ltd | Wholesale & retail | 2018 |
| Suitor Holdings Limited | Financial services | 2021 |
| Sulby Media Limited | Information & communication | 2015 |
| Summer Blueeye Limited | Wholesale & retail | 2024 |
| Summer Sunshine Group Ltd | Wholesale & retail | 2024 |
| Summerhill Residential Home Ltd | Real estate | 2010 |
| Summerhill Residential Ltd | Health & social care | 2020 |
| Sumrit Lokee Ltd | Wholesale & retail | 2024 |
| Sun Envelop Limited | Wholesale & retail | 2024 |
| Sunnies Business Ltd | Wholesale & retail | 2025 |
| Sunpro Working Holidays Ltd | Administrative & support | 2016 |
| Super FLY Papa Limited | Wholesale & retail | 2024 |
| Superior Oceans Limited | Wholesale & retail | 2016 |
| Superior Trade Frames Limited | Manufacturing | 2011 |
| Surface Scape Group Limited | Wholesale & retail | 2020 |
| SURVEY360 Ltd | Professional & scientific | 2017 |
| Sutita Limited | Wholesale & retail | 2024 |
| SV Premier Healthcare Ltd | Health & social care | 2021 |
| Sweet Babycow Limited | Wholesale & retail | 2025 |
| Sweetthunderbolt Limited | Hospitality | 2018 |
| Swim Jellyfish Limited | Wholesale & retail | 2024 |
| SX Health Full Limited | Wholesale & retail | 2023 |
| Synopsis Consulting Ltd | Wholesale & retail | 2017 |
| T-Gem Healthcare Ltd | Professional & scientific | 2019 |
| T-Mazk Properties Ltd | Real estate | 2022 |
| T. Monson & Sons Limited | Professional & scientific | 2013 |
| Table 10 (NI) Ltd | Administrative & support | 2008 |
| Tahongat Limited | Wholesale & retail | 2025 |
| Takegood on Limited | Wholesale & retail | 2025 |
| Talkerwalker Limited | Extraterritorial | 2024 |
| Tandongsheng Ltd | Wholesale & retail | 2025 |
| Tanming Limited | Wholesale & retail | 2024 |
| Tantouowunretail Limited | Wholesale & retail | 2025 |
| Tapologo Limited | Health & social care | 2024 |
| Tararat Limited | Construction | 1999 |
| Task Project Management Limited | Construction | 2008 |
| Task Recruitment Limited | Administrative & support | 2008 |
| Tata Warm Limited | Wholesale & retail | 2024 |
| TAU Industries Limited | Wholesale & retail | 2024 |
| Tayo Truck Limited | Wholesale & retail | 2025 |
| TB65 Ltd | Arts & recreation | 2015 |
| TDB Enterprises Ltd | Extraterritorial | 2020 |
| Tech Angel Criton Limited | Wholesale & retail | 2025 |
| Technical Metals Limited | Manufacturing | 1995 |
| Teddy Bear 83 Ltd | Hospitality | 2024 |
| Tegulas (N.I) Ltd | Wholesale & retail | 2022 |
| TEN Moon Ltd | Wholesale & retail | 2024 |
| Tenoz Ltd | Health & social care | 2019 |
| Tenxi Tech Ltd | Wholesale & retail | 2025 |
| Texerit Limited | Manufacturing | 2017 |
| Tezoogo Limited | Wholesale & retail | 2024 |
| TH Offshore Ltd | Transport & logistics | 2024 |
| Thai Easy Cooking Ltd | Hospitality | 2025 |
| Thames Valley Technologies Yuhong Limited | Wholesale & retail | 2023 |
| THE ARK Open Farm Limited | Agriculture & fishing | 2023 |
| THE BEE Haven Beekeepers Ltd | Other services | 2019 |
| THE Bengal Brasserie Belfast Ltd | Hospitality | 2011 |
| THE Big Yellow Skip Co NI Ltd | Real estate | 2022 |
| THE Boilerworks (NI) Limited | Construction | 2012 |
| THE Climbing Tree Playcare Ltd | Health & social care | 2016 |
| THE Cutfather (Comber) Limited | Other services | 2024 |
| THE Embassy Sports Hub Ltd | Wholesale & retail | 2026 |
| THE Ferryman Property Co Limited | Real estate | 2023 |
| THE Friends of Assisi Animal Sanctuary | Professional & scientific | 2003 |
| THE Grass That Doesn'T Grow Ltd | Administrative & support | 2012 |
| THE Herb Room Limited | Wholesale & retail | 2011 |
| THE Holiday Ninja Ltd | Information & communication | 2016 |
| THE Home of Blinds Ltd | Wholesale & retail | 2026 |
| THE Lifeleague/Prolife Care Ltd | Hospitality | 2026 |
| THE MAN Cave Newtownards Ltd | Other services | 2019 |