| Trinity AM Automation Ltd | Information & communication | 2025 |
| Trinity Entertainment Limited | Information & communication | 2017 |
| Trinity Freight Management Limited | Transport & logistics | 2014 |
| Trinity Green (Midlands) Limited | Real estate | 2021 |
| Trinity Green Residents Management Company Limited | Households | 2021 |
| Trinity Lodge Management Company Limited | Real estate | 2012 |
| Trio Jaunt Limited | Health & social care | 2018 |
| Triple a Plus Ltd | Wholesale & retail | 2020 |
| Triple B'S Micropubs Ltd | Hospitality | 2020 |
| Triple M Joinery & Building Ltd | Construction | 2015 |
| TRIPLE888VAPE Ltd | Wholesale & retail | 2017 |
| Triplecross Ltd | Manufacturing | 2023 |
| Trips and Transfers Ltd | Transport & logistics | 2025 |
| Triram Consultancy Ltd | Financial services | 2017 |
| Trisha Haulage Ltd | Transport & logistics | 2021 |
| Trishgangolli Limited | Health & social care | 2017 |
| Triskelion Engineering Ltd | Professional & scientific | 2019 |
| Triton (East Midlands) Limited | Manufacturing | 1998 |
| Trivant Ltd | Real estate | 2026 |
| Triveni Solutions Limited | Information & communication | 2014 |
| Trivium Consulting Limited | Professional & scientific | 2021 |
| Troople Ltd | Professional & scientific | 2019 |
| Tropicana Studios Limited | Manufacturing | 1991 |
| Tropicanna Horticulture Ltd | Wholesale & retail | 2010 |
| Tropixx Restaurant Ltd | Hospitality | 2023 |
| Tropixx Takeaway Limited | Hospitality | 2023 |
| Trot on Trailers Ltd | Wholesale & retail | 2020 |
| Troy Barbers Limited | Other services | 2016 |
| Troy Browne Design Ltd | Professional & scientific | 2026 |
| Troy Business Services Ltd | Professional & scientific | 2006 |
| TRS Property Holdings Ltd | Financial services | 2022 |
| Trubaly Exclusive Ltd | Health & social care | 2018 |
| Truck Parts 4 U Ltd | Extraterritorial | 2013 |
| Truck-Tech Services Ltd | Wholesale & retail | 2025 |
| Trucklink.Eu Ltd | Transport & logistics | 2006 |
| Trucklog Limited | Professional & scientific | 2000 |
| True Design Aesthetics Ltd | Other services | 2024 |
| True Edge Consulting Limited | Real estate | 2024 |
| True Estates Ltd | Real estate | 2024 |
| True Forestry Limited | Wholesale & retail | 2020 |
| True Group Ltd | Professional & scientific | 2025 |
| True Plant Hire Ltd | Administrative & support | 2018 |
| True Self Wealth Ltd | Financial services | 2021 |
| True Tone Decorators Ltd | Construction | 2025 |
| True Vision Optics Ltd | Professional & scientific | 2022 |
| Truebond.Buildingservices Ltd | Construction | 2024 |
| Truecore Global Limited | Wholesale & retail | 2025 |
| Truedatum Ltd | Manufacturing | 2025 |
| Truelead Strategy & Marketing Limited | Professional & scientific | 2024 |
| Trueline Midlands Ltd | Construction | 2019 |
| Truespan Group Ltd | Construction | 2026 |
| Truewood Ltd | Agriculture & fishing | 2026 |
| Trulee Restaurants Ltd | Hospitality | 2017 |
| Trust Car Sales Ltd | Wholesale & retail | 2025 |
| Trust Compassionate Care Limited | Health & social care | 2026 |
| Trust PDS Limited | Information & communication | 2025 |
| Trusted Takeaways Ltd | Professional & scientific | 2023 |
| Trusty Pet Supplies Limited | Wholesale & retail | 2018 |
| Truth Markers CIC | Health & social care | 2026 |
| Truvu Design Services Limited | Information & communication | 1998 |
| TRY Hard Limited | Extraterritorial | 2021 |
| TRY Harder Limited | Arts & recreation | 2021 |
| Tryphena & Tryphosa Property Ltd | Real estate | 2026 |
| Tryphena-Phosa Ltd | Health & social care | 2021 |
| TRYUS4TYRES Ltd | Wholesale & retail | 2019 |
| TS Consultancy Services Limited | Professional & scientific | 2009 |
| TS Dhillon Building Contractors Ltd | Construction | 2024 |
| TS Lally Limited | Wholesale & retail | 2023 |
| TS Medical Services Ltd | Health & social care | 2014 |
| TS83 Trading Limited | Wholesale & retail | 2023 |
| Tsan Investments Ltd | Real estate | 2023 |
| TSB Consultancy Ltd | Information & communication | 2023 |
| TSG Developments Ltd | Construction | 2017 |
| Tshirt Design X Ltd | Manufacturing | 2026 |
| Tshirt Print X Ltd | Manufacturing | 2026 |
| Tshirt Printing Design Ltd | Manufacturing | 2026 |
| Tshirt Printz Ltd | Manufacturing | 2026 |
| Tsndistribution.Co Ltd | Wholesale & retail | 2025 |
| TSO UK Limited | Wholesale & retail | 2021 |
| Tspanelling Ltd | Construction | 2020 |
| TSS Food & Beverages Ltd | Hospitality | 2020 |
| TSS Living Ltd | Real estate | 2023 |
| TSS Security Systems Limited | Manufacturing | 2005 |
| TST Nottingham Tyres Auto Ltd | Wholesale & retail | 2019 |
| Tsuki Derby Limited | Hospitality | 2021 |
| TSV Pharma Services Ltd | Wholesale & retail | 2023 |
| TT Number 1 Limited | Financial services | 2025 |
| TT Sports and Prestige Limited | Wholesale & retail | 2007 |
| TT3 Estates Ltd | Real estate | 2020 |
| TTD Properties Ltd | Real estate | 2020 |
| Ttfn (UK) Limited | Information & communication | 2026 |
| TTG Global Solutions Group Limited | Professional & scientific | 2022 |
| TTG Global Solutions Limited | Professional & scientific | 2020 |
| TTG Limited | Real estate | 2020 |
| TTK Trans Ltd | Construction | 2018 |
| Ttpd Ltd | Real estate | 2015 |
| TTS Adventures Ltd | Administrative & support | 2026 |
| Ttssderby Ltd | Information & communication | 2019 |
| Tubeweld Engineering Limited | Extraterritorial | 1971 |
| Tubeweld Engineering Services Limited | Manufacturing | 2009 |