| Timon Samra Associates Limited | Professional & scientific | 2011 |
| Tiro Media Ltd | Information & communication | 2014 |
| Titan Legal & Commercial Ltd | Professional & scientific | 1992 |
| TJT Eiddo Limited | Real estate | 2016 |
| TOB Holdings Limited | Financial services | 2023 |
| Tofiat Care Limited | Health & social care | 2023 |
| Tomlinson Wood Conveyancing Limited | Professional & scientific | 2026 |
| Top Marks Building & Maintenance Limited | Other services | 2021 |
| Topaz Property Limited | Real estate | 2022 |
| Topicformat Limited | Real estate | 1998 |
| Topico Limited | Hospitality | 2012 |
| Toro Travel Ltd | Other services | 2023 |
| Touch Rugby (Wales) Ltd | Arts & recreation | 2014 |
| Tower Training and Consultancy Ltd | Professional & scientific | 2018 |
| Traceability Ltd | Information & communication | 2023 |
| Tracy Myhill Associates Ltd | Professional & scientific | 2020 |
| Trade & Supplies Building and Maintenance Limited | Construction | 2008 |
| Trading Card Shop Ltd | Wholesale & retail | 2025 |
| Train and Coach Limited | Health & social care | 2021 |
| Transform My Nose Ltd | Other services | 2020 |
| Transmedia Solutions Limited | Information & communication | 1998 |
| Treats Doggy Style Ltd | Wholesale & retail | 2021 |
| Trench Capital Ltd | Financial services | 2015 |
| Trevor Davies Television Services ( Cymru ) Limited | Information & communication | 2008 |
| Triple Crown Bingo Limited | Arts & recreation | 1979 |
| Triumph.Vii Limited | Financial services | 2023 |
| Trivela Consulting Ltd | Professional & scientific | 2026 |
| TRJ Holdings Ltd | Financial services | 2024 |
| Trotman Edits Ltd | Information & communication | 2023 |
| True Perfection Detailing Ltd | Wholesale & retail | 2018 |
| Truffle Group Holdings Limited | Financial services | 2021 |
| Trumpton House Ltd | Real estate | 2013 |
| Trumpton Management Co Ltd | Administrative & support | 2016 |
| Tugance Ltd | Wholesale & retail | 2026 |
| Turner Miniatures Ltd | Professional & scientific | 2024 |
| Tutti Media Limited | Arts & recreation | 2017 |
| TY Hafan | Health & social care | 1995 |
| TY Hafan Awen Limited | Health & social care | 2026 |
| TY Hafan Trading Limited | Wholesale & retail | 2004 |
| TY Seven Limited | Wholesale & retail | 2023 |
| TY Unity LLP | | 2026 |
| Ty-Morgan-Spencer Limited | Real estate | 2021 |
| Tycoons Syndicate Limited | Real estate | 2020 |
| Tyle Garw Hydro Ltd | Energy | 2024 |
| UK Commercial GAS Limited | Construction | 2011 |
| Umpalumpa Sweetshop Limited | Wholesale & retail | 2014 |
| Uni-Dor Limited | Manufacturing | 1995 |
| Unique Property Sourcing Ltd | Financial services | 2018 |
| Unlock Consultancy Limited | Professional & scientific | 2018 |
| Unrestricted Investments Ltd | Financial services | 2020 |
| Upmyfoodrating Ltd | Professional & scientific | 2022 |
| Upper Cliff Limited | Real estate | 2016 |
| Uppercliff Close Limited | Households | 2018 |
| Urban Gorilla Ltd | Professional & scientific | 2024 |
| Urban Hideaways Ltd | Real estate | 2023 |
| Utahs Coffee Co Limited | Manufacturing | 2026 |
| Vadharya Enterprises Ltd | Wholesale & retail | 2023 |
| Vale Carpentry & Interiors Limited | Construction | 2016 |
| Vale Menopause Advisory Services Ltd | Health & social care | 2024 |
| Vale Occupational Medical Services Ltd | Professional & scientific | 2014 |
| Vale of Glamorgan Eats Ltd | Hospitality | 2021 |
| Vale Tennis Academy Limited | Arts & recreation | 2013 |
| Valentine Interiors Limited | Manufacturing | 2023 |
| Valueblinds Limited | Construction | 2012 |
| Van and Vehicle Window Specialists Ltd. | Wholesale & retail | 2018 |
| Vanishing MAN Project Ltd | Professional & scientific | 2025 |
| Vargo Recruitment Ltd | Administrative & support | 2016 |
| Vcjh Limited | Other services | 2020 |
| Verici DX PLC | Professional & scientific | 2020 |
| Veritas House Ltd | Professional & scientific | 2021 |
| Vieve Tattoos Ltd | Other services | 2024 |
| Vintage Drinks Ltd | Hospitality | 2025 |
| Virtihealth Limited | Information & communication | 2017 |
| Vision on Fire & Security Ltd | Administrative & support | 2009 |
| Vithayathil Ltd | Health & social care | 2023 |
| VM Training Ltd | Health & social care | 2018 |
| VOG Drone Services Limited | Information & communication | 2024 |
| Voyager Financial Services Limited | Financial services | 1996 |
| W & P Property Limited | Real estate | 2017 |
| W C K a Ltd | Arts & recreation | 2009 |
| Walalooo Collectables Ltd | Wholesale & retail | 2024 |
| Wales FAN Zone Ltd | Hospitality | 2024 |
| Wales Interactive Development Limited | Information & communication | 2014 |
| Wales Interactive Group Limited | Information & communication | 2017 |
| Wales Interactive Limited | Information & communication | 2011 |
| Walton House Management Company Limited | Households | 2004 |
| Washington House (Penarth) Management Company Limited | Households | 2026 |
| Washington Penarth RTM Company Limited | Households | 2025 |
| Watches of the VALE1 Limited | Wholesale & retail | 2022 |
| WAX & GLO Limited | Other services | 2018 |
| Wcka Pontypridd & Welsh Valleys Limited | Arts & recreation | 2007 |
| WE DO Cover Ltd | Financial services | 2013 |
| Wealthify Limited | Financial services | 2014 |
| Webjewel Digital Marketing Ltd | Professional & scientific | 2020 |
| WEE Bricks Ltd | Real estate | 2021 |
| Weird Triangle Limited | Manufacturing | 2017 |
| Welcomeplace Property Management Limited | Households | 1992 |
| Well-Being of Wales (WOW) Ltd | Professional & scientific | 2025 |
| Wellness Consultancy Group Ltd | Professional & scientific | 2024 |
| Wellspring Consulting Limited | Professional & scientific | 2010 |