| Sanderson-Duff Ltd | Real estate | 2025 |
| Sang-Ngak-Chö-Dzong | Other services | 2018 |
| Sarnau Army Surplus Limited | Wholesale & retail | 2006 |
| Sbardun CYF | Administrative & support | 2011 |
| Schooners Wine Bar Limited | Hospitality | 2013 |
| Seals Bay Cafe Limited | Transport & logistics | 2026 |
| Second Chances Animal Sanctuary Ltd | Other services | 2025 |
| Second Chances Sanctuary CIC | Other services | 2026 |
| Second Key Estates Ltd | Real estate | 2026 |
| Shadows Management 2 Ltd | Financial services | 2024 |
| Shaggy Sheep Limited | Administrative & support | 2012 |
| SHW Trading Ltd | Financial services | 2026 |
| Siddall's (Hunnington) Limited | Real estate | 1950 |
| Simans Ltd | Real estate | 2024 |
| Sizzle Stop Ltd | Hospitality | 2025 |
| SPG Autocare Ltd | Wholesale & retail | 2020 |
| Spring Hollow Limited | Hospitality | 2019 |
| Spring Valley Films Ltd | Manufacturing | 2019 |
| ST Stephen's GAS Limited | Mining & quarrying | 2010 |
| Standing Stone Productions Limited | Information & communication | 2025 |
| Standing Stone Properties Ltd | Real estate | 2025 |
| Stockinjur Limited | Administrative & support | 2014 |
| Stonepower Limited | Information & communication | 2003 |
| Storfa JJ Stores Ltd | Wholesale & retail | 2016 |
| T J Campbell and Sons Ltd | Manufacturing | 2024 |
| T J Williams and SON Limited | Other services | 2014 |
| TAI Coed Ltd | Construction | 2021 |
| TAI Tysul Homes Ltd | Construction | 2018 |
| Tail Wagging Temptations Ltd | Wholesale & retail | 2024 |
| TAJ Indian Takeaway Ltd | Hospitality | 2021 |
| Technical & Graphic Design Services Limited | Professional & scientific | 2015 |
| Teifi Coffee Ltd | Wholesale & retail | 2018 |
| Teifi CYF | Construction | 2026 |
| Teifi Organics Ltd | Professional & scientific | 2022 |
| Teifi Valley Camping Ltd | Hospitality | 2026 |
| Teifi Web Ltd | Information & communication | 2021 |
| TGM Engineering Limited | Manufacturing | 2008 |
| THE Arcade (Llandysul) Limited | Wholesale & retail | 1999 |
| THE Balloon Holding Company Limited | Information & communication | 2004 |
| THE Beach HUT Llangrannog Limited | Hospitality | 2003 |
| THE Busy BEE Cafe Limited | Hospitality | 2015 |
| THE Crunchy Cheese Company Limited | Manufacturing | 2020 |
| THE Flying Fish Studios Ltd | Arts & recreation | 2002 |
| THE Gingerly Green Ltd | Wholesale & retail | 2022 |
| THE Great Makombe African Store Ltd | Wholesale & retail | 2026 |
| THE Hiveaway Glamping Limited | Hospitality | 2019 |
| THE Hungry Trout Limited | Hospitality | 2011 |
| THE Lloyd Life Limited | Information & communication | 2024 |
| THE Ship Catering Ltd | Hospitality | 2019 |
| THE Solutions Factory Ltd. | Information & communication | 1998 |
| THE Teifi Valley Railway Limited | Transport & logistics | 1973 |
| Thomas Jones Ltd | Other services | 2020 |
| Thomas Login Architecture Limited | Professional & scientific | 2023 |
| Thomas Macrae Limited | Construction | 2010 |
| Thomas Safety Services Ltd | Professional & scientific | 2013 |
| Times TEN Limited | Information & communication | 2013 |
| TL Socials Ltd | Information & communication | 2025 |
| Traolo Limited | Hospitality | 2025 |
| Tregroes Waffle Bakery Ltd | Manufacturing | 2004 |
| Tudor Hall Energy Europe Limited | Mining & quarrying | 2014 |
| Tudor Hall Energy Limited | Mining & quarrying | 2009 |
| TVG Llandysul Limited | Professional & scientific | 2010 |
| TWO4CAT Limited | Construction | 1998 |
| Tydu Vale Limited | Hospitality | 2024 |
| Uave Limited | Professional & scientific | 2013 |
| Urban FM Ltd | Construction | 2024 |
| Valley View Hideaway Ltd | Hospitality | 2023 |
| Veggie Cwtch Limited | Manufacturing | 2017 |
| Veritas Site Solutions Ltd | Construction | 2025 |
| Vince Films Limited | Information & communication | 2021 |
| W D Hayday Limited | Construction | 1994 |
| WA a ME Davies CYF | Agriculture & fishing | 2003 |
| Waunfawr Farms Limited | Agriculture & fishing | 2004 |
| Webuystatics.Com Ltd | Wholesale & retail | 2018 |
| Well Drilling (UK) Ltd | Construction | 2008 |
| West Coast Foods (Wales) Limited | Wholesale & retail | 2025 |
| West Coast Machinery Ltd | Wholesale & retail | 2018 |
| West Cross Estates Limited | Real estate | 2009 |
| West Spark Media Limited | Professional & scientific | 2025 |
| West Wales Forestry Services Limited | Agriculture & fishing | 2026 |
| West Wales Kitchens Ltd | Wholesale & retail | 2023 |
| West Wales Luxury Lodges Limited | Hospitality | 2025 |
| West Wales Rally Fabrications Ltd | Administrative & support | 2004 |
| WGD Plant Hire Ltd | Construction | 2024 |
| Wild Wellingtons Ltd | Hospitality | 2017 |
| Williams Sheds Ltd | Wholesale & retail | 2013 |
| Wise OWL Sound Limited | Professional & scientific | 2023 |
| Wiselan Limited | Information & communication | 1999 |
| Wonkey IT Ltd | Information & communication | 2020 |
| Woodbine Roofing Limited | Construction | 2008 |
| WPC Bricklaying Specialist Ltd | Construction | 2025 |
| WY Ddraig CYF | Hospitality | 2018 |
| WYN Owens Ltd | Wholesale & retail | 2012 |
| Y Gampfa Ltd | Arts & recreation | 2024 |
| YES Property Maintenance Ltd | Construction | 2025 |
| Ymddiriedolwyr Tregroes Cyfyngedig | Extraterritorial | 2016 |
| YR Ardd C.I.C. | Agriculture & fishing | 2021 |
| Ysgol Y BYD CYF | Education | 2020 |
| Ysgolion OT CYF. | Education | 2022 |