| Stitched Ltd | Manufacturing | 2020 |
| Strong Training Limited | Arts & recreation | 2011 |
| Studio Five Interiors Limited | Professional & scientific | 2025 |
| Studio Goldstar Limited | Information & communication | 2023 |
| SU Turney Consulting Limited | Professional & scientific | 2012 |
| Sullivan Architectural Limited | Professional & scientific | 2018 |
| Summer Bliss Limited | Hospitality | 2024 |
| Sunflower Cleaning Ltd | Administrative & support | 2023 |
| Tachotech Ltd | Professional & scientific | 2023 |
| Talent Wing Ltd | Administrative & support | 2014 |
| Team Frith Limited | Extraterritorial | 2002 |
| Techways LLP | | 2013 |
| Tegwen Homes Limited | Real estate | 2025 |
| Tenergise Ltd | Wholesale & retail | 2021 |
| Tenuta Consulting Limited | Professional & scientific | 2023 |
| Teratorq Ltd | Professional & scientific | 2016 |
| Thaw Technology Ltd | Wholesale & retail | 2015 |
| THE Arnos Group Limited | Professional & scientific | 2023 |
| THE Boutique Cellar Limited | Manufacturing | 2012 |
| THE Dell Vineyard Ltd | Agriculture & fishing | 2021 |
| THE Engine MAN Ltd | Professional & scientific | 2025 |
| THE Fabulous Fish Company Limited | Hospitality | 2012 |
| THE Farrier Centre Limited | Professional & scientific | 2024 |
| THE Glascoed HWB & Wellbeing Centre CIC | Health & social care | 2024 |
| THE HOG Roast Oven Company Limited | Manufacturing | 2010 |
| THE Little Umbrella Story House Ltd | Health & social care | 2025 |
| THE MAD Platter USK Ltd | Hospitality | 2017 |
| THE Medical Trauma Collaborative Limited | Health & social care | 2026 |
| THE Olive Tree (Cwmbran) Limited | Hospitality | 2013 |
| THE Penyrheol Cwrt Ltd | Households | 2000 |
| THE Photography Workshop Limited | Professional & scientific | 2013 |
| THE Protium Group Limited | Wholesale & retail | 2020 |
| THE Roger Edwards Field Limited | Arts & recreation | 2015 |
| THE Soulful Explorer Limited | Manufacturing | 2023 |
| THE Welsh Truffle Company LLP | | 2022 |
| The-Paintbox Ltd | Wholesale & retail | 2012 |
| Theeom Ltd | Wholesale & retail | 2019 |
| This IS Shane Williams Limited | Other services | 2013 |
| Thomas James UK Limited | Construction | 2018 |
| TIM Jenkins Agricultural Engineering Ltd | Manufacturing | 2016 |
| Timothy Addison Ross Limited | Manufacturing | 2008 |
| TJC Developments Ltd | Real estate | 2010 |
| Top Dog Trades Limited | Administrative & support | 2007 |
| TP Training Ltd | Health & social care | 2014 |
| Trefynwy Adjusters Limited | Financial services | 2007 |
| Trelawney House Management Company Limited | Households | 1999 |
| Trem Pant Glas Management Limited | Households | 2023 |
| Trinserv Limited | Real estate | 2015 |
| Tumptonics Ltd | Manufacturing | 2022 |
| TW Property Investments Ltd | Real estate | 2026 |
| Twist Health Limited | Professional & scientific | 2018 |
| TY Nant Educational Services Limited | Professional & scientific | 2023 |
| TY Sign Developments Limited | Real estate | 1964 |
| UAC Field Ltd | Arts & recreation | 2016 |
| UK Registrations Limited | Extraterritorial | 2017 |
| Urban Merchant Properties Limited | Real estate | 2002 |
| USK Agricultural Limited | Agriculture & fishing | 2022 |
| USK Cabs Ltd | Transport & logistics | 2017 |
| USK Consult Ltd | Professional & scientific | 2023 |
| USK Land Survey Ltd | Professional & scientific | 2017 |
| USK Rural Life Museum | Arts & recreation | 2008 |
| USK Transport Services Ltd | Transport & logistics | 2023 |
| USK Valley Landscapes Ltd | Professional & scientific | 2025 |
| Uskbridge Motors Limited | Wholesale & retail | 2006 |
| Uskvalleyjoinery Ltd | Manufacturing | 2014 |
| Vaga Property Ltd | Construction | 2025 |
| Vanguard Property Associates Limited | Real estate | 2026 |
| Vaynor Independent Property Limited | Construction | 2016 |
| Venture Equine Rehab Ltd | Arts & recreation | 2022 |
| Vickathan Ltd | Hospitality | 2025 |
| Vitalijs Limited | Transport & logistics | 2023 |
| W Phillips Properties Limited | Real estate | 2025 |
| W.S. Automotive Limited | Wholesale & retail | 2010 |
| Walker & Coleman Limited | Health & social care | 2021 |
| Warmstyle Limited | Administrative & support | 2008 |
| WCM Farm Holdings Limited | Agriculture & fishing | 2025 |
| Wentwood Bail Property Limited | Construction | 2007 |
| Wentwood Merthyr Limited | Real estate | 2003 |
| Wentwood Pencoed Ltd | Construction | 2024 |
| Wentwood Properties Limited | Real estate | 1998 |
| Wentwood Property Services Ltd | Real estate | 2000 |
| Wentwood Swansea Limited | Real estate | 2025 |
| West Castle Limited | Construction | 2016 |
| Westgate Pallets Limited | Manufacturing | 2005 |
| White Hare Distillery Cardiff Ltd | Manufacturing | 2023 |
| White Hare Distillery Ltd | Manufacturing | 2019 |
| Williams IT Services Ltd | Information & communication | 2020 |
| Wills & Co Energy Limited | Water & waste | 2018 |
| Wizard Home Improvements Ltd | Construction | 2011 |
| WJB Clothing Limited | Wholesale & retail | 2003 |
| Woodside Service Station Ltd | Wholesale & retail | 2018 |
| Workout Online Ltd. | Health & social care | 2016 |
| Wrscontractors Ltd | Transport & logistics | 2025 |
| WYE Engineering Solutions Limited | Professional & scientific | 2025 |
| WYE Valley Tractors Limited | Manufacturing | 2021 |
| WYE Valley West Limited | Real estate | 2018 |
| Wyndermere Ltd | Real estate | 2021 |
| Ymestyn | Health & social care | 2024 |