| Tropical Emporium Limited | Wholesale & retail | 2026 |
| Tropical Infusion Spice Co Ltd | Wholesale & retail | 2026 |
| Troston Farms Limited | Agriculture & fishing | 1961 |
| Trotter & Deane Limited | Wholesale & retail | 1988 |
| Trovetech Ltd | Information & communication | 2026 |
| Trovetrendz Limited | Wholesale & retail | 2023 |
| Trowell Property & Lettings Ltd | Households | 2021 |
| Troy Productions Ltd | Information & communication | 2019 |
| TRU Gamez Limited | Information & communication | 2023 |
| True Developments Ltd | Construction | 2025 |
| True Nature Sales Ltd | Professional & scientific | 2024 |
| True Sky Group Ltd | Financial services | 2025 |
| True Sky Properties Ltd | Real estate | 2025 |
| True Tmk-Global Ltd | Wholesale & retail | 2026 |
| Trueband Ltd | Information & communication | 2026 |
| Truewood Oak Limited | Real estate | 2023 |
| Truffle Forager Limited | Hospitality | 2022 |
| Truly Vintage Limited | Wholesale & retail | 2011 |
| Trulyhers Limited | Wholesale & retail | 2025 |
| Trustcove Limited | Information & communication | 2026 |
| Trusted Foods Ltd | Manufacturing | 2025 |
| Trustedbuildernetwork Ltd | Information & communication | 2026 |
| Trustwell Mobility Ltd | Wholesale & retail | 2024 |
| Truth Non-Surgical & Wellness Ltd. | Health & social care | 2020 |
| Truth P.S Limited | Real estate | 2023 |
| Truu Skincare Ltd | Wholesale & retail | 2025 |
| Trymaze Ltd | Other services | 2021 |
| TS100 Limited | Public administration | 2023 |
| TSG (the Statham Group) Transport Ltd | Transport & logistics | 2025 |
| TSG Emergency Services Support Ltd | Health & social care | 2026 |
| Tsim Limited | Information & communication | 2023 |
| TSM Contracting Limited | Agriculture & fishing | 2019 |
| TSP Enterprises Ltd | Education | 2021 |
| Tspv Ltd | Wholesale & retail | 2022 |
| Tssc Property Sourcing Ltd | Real estate | 2025 |
| TT Cleaners Ltd | Administrative & support | 2025 |
| Tt&L Approach Ltd | Professional & scientific | 2014 |
| TTA Theatre Ltd | Households | 2019 |
| Ttfboy Ltd | Wholesale & retail | 2026 |
| Ttlperformance Ltd | Health & social care | 2025 |
| TTM Developments Ltd | Real estate | 2026 |
| Ttrlogistics Limited | Transport & logistics | 2025 |
| TU & K Enterprises Limited | Wholesale & retail | 2022 |
| Tuddi Limited | Wholesale & retail | 2025 |
| Tudor House Properties Ltd | Real estate | 2024 |
| Tudor Vehicle Specialist Limited | Wholesale & retail | 2019 |
| Tuffur Ltd | Wholesale & retail | 2019 |
| Tulevate Ltd | Education | 2026 |
| Tuneup Auto Repair Ltd | Wholesale & retail | 2026 |
| Tung Hooi Limited | Hospitality | 2018 |
| Turan Yacht Limited | Professional & scientific | 2026 |
| Turfam Property Ltd | Real estate | 2025 |
| Turiminola Limited | Construction | 2005 |
| Turkish Craft UK Ltd | Wholesale & retail | 2014 |
| Turners + Co. Limited | Real estate | 2026 |
| Turners of GT. Barton Limited | Transport & logistics | 2018 |
| Turret Lane Ipswich (Management Company) Limited | Real estate | 2003 |
| Turrim UK Ltd | Wholesale & retail | 2018 |
| Turtle Accounts Limited | Professional & scientific | 2019 |
| Tusq International Group Ltd | Education | 2025 |
| Tutela Associates Limited | Administrative & support | 2005 |
| Tutom Limited | Real estate | 2025 |
| Tutonics Ltd | Information & communication | 2013 |
| Tutor Geek Ltd | Education | 2021 |
| Tutordex Ltd | Education | 2024 |
| Tutorio Ltd | Education | 2023 |
| TVINE360 Ltd | Education | 2023 |
| Tvnta Ltd | Education | 2026 |
| Twenty Four Acres Ltd | Real estate | 2022 |
| Twenty Twenty View Limited | Real estate | 2022 |
| Twentynine Media Limited | Professional & scientific | 2019 |
| Twentysixsolutions Ltd | Administrative & support | 2024 |
| Twga LLP | | 2019 |
| Twine Market Ltd | Wholesale & retail | 2025 |
| Twinkle Project Ltd | Wholesale & retail | 2025 |
| Twinpeak Ventures Ltd | Professional & scientific | 2017 |
| TWL Group Limited | Wholesale & retail | 2018 |
| Two CAN Talk Property Limited | Professional & scientific | 2025 |
| Two CAN Talk Speech Therapy Limited | Professional & scientific | 2013 |
| Two Day Limited | Real estate | 2009 |
| Twocurves Ltd | Wholesale & retail | 2025 |
| TWS Concierge Services Limited | Other services | 2025 |
| TY FIN Cottage Limited | Real estate | 2024 |
| Tyddewi Limited | Wholesale & retail | 2021 |
| Tyde Media Ltd | Wholesale & retail | 2025 |
| Tyneside Holdings Limited | Real estate | 2021 |
| Tynshine Solar Ltd | Wholesale & retail | 2025 |
| Tyrano Ltd | Wholesale & retail | 2026 |
| U CAB Limited | Transport & logistics | 2021 |
| U R Unique Ltd | Real estate | 2024 |
| U&S Global Ltd | Wholesale & retail | 2025 |
| U-Hr Consultancy Ltd | Administrative & support | 2025 |
| U.K. Equine Life Ltd | Wholesale & retail | 2010 |
| UBI Swing Limited | Construction | 2024 |
| Ubique Leadership Limited | Professional & scientific | 2020 |
| Uburu Technology Platforms Limited | Information & communication | 2022 |
| UC BPO Ltd | Information & communication | 2025 |
| Ucase Limited | Wholesale & retail | 2013 |
| UDB Consultancy Ltd | Wholesale & retail | 2020 |
| Uddogta BD Ltd | Information & communication | 2025 |