| Trading Cars UK Ltd | Wholesale & retail | 2022 |
| Traditional Touch Window Cleaning Ltd | Administrative & support | 2026 |
| Tradwithdube Ltd | Wholesale & retail | 2020 |
| Trafford Consulting Limited | Information & communication | 2013 |
| Trail View Leisure Ltd | Hospitality | 2023 |
| Trails for Good Ltd | Arts & recreation | 2024 |
| Train Motivate Excel Ltd | Professional & scientific | 2011 |
| Trainfx Limited | Manufacturing | 2011 |
| Training 2 Progress Ltd | Education | 2018 |
| Training Made Easy Ltd | Education | 2021 |
| Trans MB Ltd | Transport & logistics | 2020 |
| Trans Support Hub CIC | Wholesale & retail | 2023 |
| Trans WM Limited | Transport & logistics | 2025 |
| Trans-European Site Services Limited | Arts & recreation | 1991 |
| Trans-Portland Ltd | Transport & logistics | 2025 |
| Transaction Technologies Ltd | Information & communication | 2017 |
| Transcare 28 Holdings Limited | Financial services | 2015 |
| Transcare 28 Ltd | Manufacturing | 2007 |
| Transcare Properties Ltd | Real estate | 1993 |
| Transcargo Express Ltd | Transport & logistics | 2017 |
| Transcend Capital Limited | Real estate | 2018 |
| Transcend Consulting Limited | Professional & scientific | 2014 |
| Transcend Projects Ltd | Professional & scientific | 2017 |
| Transcend Sutras Ltd | Information & communication | 2023 |
| Transform Managed Services Limited | Education | 2014 |
| Transform Property Holdings Ltd | Financial services | 2026 |
| Transform Safety Ltd | Education | 2026 |
| TRANSFORM2OUTPERFORM Limited | Professional & scientific | 2016 |
| Transition to Adulthood Ltd | Health & social care | 2023 |
| Translink Sameday Limited | Transport & logistics | 2022 |
| Transparent Building Services Ltd | Construction | 2023 |
| TRANSPORT2 (UK) Limited | Information & communication | 2010 |
| Transporter Works Garage Limited | Manufacturing | 2021 |
| Tranters Limited | Manufacturing | 1999 |
| Trapmass Limited | Wholesale & retail | 2023 |
| Travel by Angela Ltd | Administrative & support | 2022 |
| Travel Delux Ltd | Transport & logistics | 2024 |
| Travel Hub Derby Ltd | Administrative & support | 2025 |
| Travelounge Limited | Administrative & support | 2001 |
| Trawsgoed Estates RE Limited | Real estate | 2026 |
| Trbl Group Limited | Financial services | 2025 |
| Treasuretrail Limited | Financial services | 2003 |
| Trebletap Ltd. | Wholesale & retail | 2009 |
| Treboro Consultancy Limited | Professional & scientific | 2012 |
| Tree Tops Montessori Nursery Ltd | Education | 2004 |
| Treebay Consulting Limited | Information & communication | 2023 |
| Treehouse Brewery Ltd | Manufacturing | 2021 |
| Treetops Hospice Trust | Health & social care | 1984 |
| Treetops Retail Limited | Wholesale & retail | 2003 |
| Tregynon Hall Limited | Extraterritorial | 1988 |
| Trenchant Investments Ltd | Administrative & support | 2017 |
| Trend Composites Ltd | Professional & scientific | 2019 |
| Trend Retail Solutions Limited | Construction | 2011 |
| Trendage Limited | Real estate | 2021 |
| Trendaura Ltd | Wholesale & retail | 2026 |
| Trenders Ltd | Wholesale & retail | 2024 |
| Trendico Ltd | Wholesale & retail | 2024 |
| Trendng Ltd | Professional & scientific | 2025 |
| Trendy Bazaar Ltd | Construction | 2025 |
| Trent Concrete Ltd | Manufacturing | 2024 |
| Trent Doors Ltd | Construction | 2024 |
| Trent Engineering Group Ltd | Construction | 2021 |
| Trent Engineering Services Ltd | Extraterritorial | 2024 |
| Trent Financial Management Limited | Professional & scientific | 2017 |
| Trent Horizon Ltd | Administrative & support | 2026 |
| Trent Valley Reman Solutions Limited | Manufacturing | 2022 |
| Trent Valley Service Centre Limited | Wholesale & retail | 2003 |
| Trentham Manor Estate Management Company Limited | Households | 2015 |
| Trentstone Estates Holdings Limited | Financial services | 2025 |
| Trentstone Living Ltd | Real estate | 2025 |
| Tresnet Limited | Hospitality | 2021 |
| Trevor Collington and Sons Limited | Construction | 2003 |
| TRG Bonds II Limited | Financial services | 2015 |
| TRG Bonds III Limited | Financial services | 2015 |
| TRG Bonds IV Limited | Financial services | 2015 |
| TRG Bonds Limited | Professional & scientific | 2014 |
| TRG Bonds V Limited | Financial services | 2015 |
| TRG Bonds VI Limited | Financial services | 2015 |
| TRG Bonds VII Limited | Financial services | 2016 |
| TRG Bonds Viii Limited | Financial services | 2016 |
| TRG Security Ltd | Construction | 2019 |
| Trgom Limited | Real estate | 2008 |
| TRI Property Services Limited | Real estate | 2018 |
| TRI Spark Ltd | Wholesale & retail | 2025 |
| TRI Tones Music Limited | Arts & recreation | 2020 |
| Triaz Ltd | Professional & scientific | 2023 |
| Trice Construction Ltd | Construction | 2020 |
| Trice Projects Ltd | Construction | 2026 |
| Tricia Foster Consulting Ltd | Information & communication | 2026 |
| Tricia Woolston Limited | Arts & recreation | 2013 |
| Trident Property Development Limited | Real estate | 2020 |
| Trifecta Healthcare and Support Services Ltd | Hospitality | 2015 |
| Triggerfish Games Ltd | Arts & recreation | 2016 |
| Trigon Group Limited | Financial services | 2008 |
| Trigon Holdings Limited | Financial services | 1979 |
| Triko Property Limited | Real estate | 2023 |
| Trimmings by Design (Holdings) Limited | Financial services | 2019 |
| Trimmings by Design Limited | Manufacturing | 1999 |
| Trimurti Holdings Ltd | Hospitality | 2026 |
| Trimz on Rimz Ltd | Other services | 2026 |