| Solve Consulting (SW) Limited | Construction | 2014 |
| Soma Vita Ltd | Other services | 2020 |
| South East Wales Biodiversity Records Centre Limited | Information & communication | 2003 |
| South Wales Farm Vets Ltd | Professional & scientific | 2017 |
| South Wales LOG Burners Ltd | Construction | 2021 |
| SP Events UK Ltd | Administrative & support | 2020 |
| Sparkle and Shine Commercial External Cleaning Services Ltd | Administrative & support | 2025 |
| Sparkle and Shine Domestic and Commercial Cleaning Ltd | Administrative & support | 2017 |
| Sparkle and Shine External Cleaning Services Ltd | Administrative & support | 2025 |
| Sparkles Cleaning Specialists Limited | Other services | 2019 |
| SPC Elite Physiotherapy Limited | Other services | 2012 |
| SPEAK2BEN Ltd | Financial services | 2021 |
| Sphere Rail Ltd | Construction | 2019 |
| Spms SW Limited | Wholesale & retail | 2023 |
| Sportlink Limited | Information & communication | 2026 |
| Spot on Taxis Limited | Transport & logistics | 2023 |
| Stapleton's Mobile Valeting Ltd | Administrative & support | 2025 |
| Starrd Financial Solutions Ltd | Financial services | 2025 |
| Starrd Solutions Ltd. | Professional & scientific | 2017 |
| Station Cafe (Pontyclun) Limited | Hospitality | 2021 |
| Steak and PIG Ltd | Hospitality | 2021 |
| Stephenslaw Limited | Professional & scientific | 2025 |
| Stereomedics Ltd | Health & social care | 2019 |
| Steve Thomas CYF | Extraterritorial | 2018 |
| Stone Supplies (Wales) Limited | Manufacturing | 2008 |
| Strategic Land Developments Limited | Real estate | 2010 |
| Strength in YOU Ltd | Health & social care | 2024 |
| Strengthx Ltd | Wholesale & retail | 2024 |
| Structural Productions Ltd | Professional & scientific | 2024 |
| Stuart Smith Building Solutions Ltd | Construction | 2016 |
| Studio Buzzard Ltd | Professional & scientific | 2020 |
| Summers-James Limited | Information & communication | 2011 |
| Sun City Pontyclun Limited | Real estate | 2005 |
| Sunshine Meadows Limited | Extraterritorial | 2021 |
| Support Services Group Limited | Construction | 2019 |
| SW Consult Limited | Professional & scientific | 2021 |
| Swanheart Ltd | Information & communication | 2023 |
| Swiftree Solutions Ltd | Wholesale & retail | 2023 |
| Swizzle Securities Limited | Administrative & support | 2009 |
| T and D Pubs Limited | Hospitality | 2025 |
| T Gilpin Physio Consultancy Ltd | Health & social care | 2025 |
| T R Davies Limited | Professional & scientific | 2003 |
| T30 Landscaping Ltd | Administrative & support | 2021 |
| Talbot Pizza Ltd | Hospitality | 2023 |
| Talbot Stores Limited | Wholesale & retail | 2024 |
| Taler Global Solutions Ltd | Financial services | 2014 |
| Talib Barbers Ltd | Other services | 2024 |
| Tallulah Lily Cakes Ltd | Manufacturing | 2022 |
| Talygarn Mews Management Limited | Real estate | 1998 |
| Tame the Mane Limited | Other services | 2019 |
| Tarian Drums Cyfyngedig | Manufacturing | 2020 |
| Taylord Property Ltd | Real estate | 2025 |
| TBO Properties Limited | Real estate | 2022 |
| TBO Textiles Ltd | Financial services | 2024 |
| TBT Security (UK) Ltd | Wholesale & retail | 2018 |
| Tea, Coffee & Cake Limited | Hospitality | 2017 |
| Teamthie Ltd | Wholesale & retail | 2025 |
| Tech Digital Services Limited | Information & communication | 2025 |
| Technical Engineering Ltd | Manufacturing | 2017 |
| Tegm Enterprise Ltd | Professional & scientific | 2020 |
| Tell IT Your Way Limited | Information & communication | 2021 |
| Tempest Tattoo Limited | Arts & recreation | 2022 |
| Teulu Wealth Investments Limited | Financial services | 2024 |
| THE Backyard Barber HC Ltd | Other services | 2020 |
| THE Badgers TRY Line Cafe Trading AS Llanharry Working MES Cafe Limited | Hospitality | 2026 |
| THE Beauty HUT Pontyclun Limited | Other services | 2022 |
| THE Bespoke Furniture Company Limited | Wholesale & retail | 2024 |
| THE Blinds Trade Centre UK Ltd | Manufacturing | 2014 |
| THE Bookkeeping Hub Ltd | Professional & scientific | 2016 |
| THE Brunch Stop Limited | Hospitality | 2018 |
| THE Butcher's Bar & Grill Limited | Hospitality | 2026 |
| THE COT Collection Ltd | Agriculture & fishing | 2022 |
| THE Craffted Limited | Information & communication | 2023 |
| THE Dynevor Arms Limited | Hospitality | 2023 |
| THE Engineered Stone Co Ltd | Wholesale & retail | 2018 |
| THE Food Portfolio Limited | Wholesale & retail | 2016 |
| THE Francis Leather Company Ltd | Wholesale & retail | 2019 |
| THE G & R Drinks Group Ltd | Wholesale & retail | 2021 |
| THE Greatest TRY Limited | Extraterritorial | 2021 |
| THE Grey Hare Candle Co Ltd | Manufacturing | 2020 |
| THE Hire House Limited | Extraterritorial | 2016 |
| THE Hunting Shop Ltd | Wholesale & retail | 2014 |
| THE Letter Doctor Ltd | Wholesale & retail | 2025 |
| THE Luxury Event Group Ltd | Financial services | 2026 |
| THE Mint Directors’ Association Limited | Other services | 2023 |
| THE New Best Burger Van Ltd | Hospitality | 2018 |
| THE Nutrivend Group Limited | Wholesale & retail | 2025 |
| THE Penny Farthing Ltd | Hospitality | 2019 |
| THE Pipeworks Bar Ltd | Hospitality | 2018 |
| THE Role UP Limited | Arts & recreation | 2021 |
| THE Rolling Box LLP | | 2021 |
| THE Royal Mint Limited | Manufacturing | 2009 |
| THE Royal Mint Museum | Education | 2009 |
| THE Royal Mint Museum Services Limited | Professional & scientific | 2009 |
| THE ST Lawrence at Lavernock Trust | Other services | 2009 |
| THE TAP END Holdings Ltd | Financial services | 2021 |
| THE TAP END Installations Ltd | Extraterritorial | 2021 |
| THE TAP END Limited | Wholesale & retail | 2017 |
| THE Thirsty Elephant Ltd | Hospitality | 2020 |
| THE Wild Orchid Florist Ltd | Wholesale & retail | 2023 |