| Thrive Finance Limited | Professional & scientific | 2025 |
| Thrive Tree Consultancy Ltd | Professional & scientific | 2025 |
| Thriving Beyond the Label C.I.C. | Health & social care | 2025 |
| Thriving Learning Online Unit Limited | Professional & scientific | 2023 |
| Through the Grape Van Limited | Wholesale & retail | 2018 |
| Throughlineconsulting Ltd | Professional & scientific | 2026 |
| Thunder Maintenance Ltd | Construction | 2026 |
| Thurloe Thoroughbred Services Limited | Arts & recreation | 2024 |
| TI Consulting Limited | Professional & scientific | 2014 |
| Tian YU Association International | Health & social care | 2014 |
| Tianjin Siying International Freight Forwarding Co., Ltd | Wholesale & retail | 2026 |
| Tianjin Tiema Trading Co., Limited | Wholesale & retail | 2024 |
| Tianjin Yiti Trading Co., Ltd | Wholesale & retail | 2025 |
| Tianjin Zhirong Trading Co., Ltd | Wholesale & retail | 2025 |
| Tiantangtu Trading Co., Ltd | Wholesale & retail | 2025 |
| Tianxi Metal Co., Ltd | Agriculture & fishing | 2023 |
| Tianze Machinery Technology Co., Ltd | Extraterritorial | 2017 |
| Tianzhou Trading Co., Ltd | Wholesale & retail | 2024 |
| Tibusch Fashion Ltd | Wholesale & retail | 2024 |
| Tichelea Iulian Valentin Ltd | Manufacturing | 2025 |
| Tickety BOO Productions Ltd | Professional & scientific | 2016 |
| Tickety-Boo Accounting Limited | Professional & scientific | 2021 |
| Tidalsense Limited | Professional & scientific | 2013 |
| Tidecraft Marine Carpentry Ltd | Manufacturing | 2025 |
| Tidegate Limited | Households | 2007 |
| Tidylinker Ltd | Administrative & support | 2025 |
| Tidyspark Cleaning Services Ltd | Administrative & support | 2025 |
| Tiffy Rook Limited | Other services | 2015 |
| Tiger Blue Studios Ltd | Real estate | 2017 |
| Tiger Private Hire Limited | Transport & logistics | 2024 |
| Tiger's EYE Ltd | Manufacturing | 2017 |
| Tigers Real Estate UK Limited | Real estate | 2024 |
| Tigris Active Limited | Wholesale & retail | 2025 |
| Tikka Box Ltd | Hospitality | 2025 |
| Tila Edtech Ltd | Education | 2019 |
| Tilda & Co Properties Limited | Real estate | 2025 |
| Tilki AI Limited | Information & communication | 2024 |
| Tilswall Colorful Life Technology Limited | Wholesale & retail | 2025 |
| Tilt 23 Limited | Professional & scientific | 2024 |
| TIM Elcock Limited | Professional & scientific | 2003 |
| TIM Elsigood Associates Limited | Health & social care | 2008 |
| TIM Griggs Associates Limited | Information & communication | 2025 |
| TIM HAM Neurology Limited | Health & social care | 2023 |
| Time & Tide (Bedford) Limited | Professional & scientific | 2006 |
| Time and Tide Consulting Ltd | Professional & scientific | 2025 |
| Time Dynamics Limited | Information & communication | 2020 |
| Time Twins Limited | Professional & scientific | 2015 |
| Timegather Limited | Wholesale & retail | 2024 |
| Timeless Marine Ventures Limited | Arts & recreation | 2013 |
| Timeless Tile Store Ltd | Wholesale & retail | 2023 |
| Timeless Transformations Ltd | Construction | 2021 |
| Timeline Trading Limited | Professional & scientific | 2015 |
| Timely Link Limited | Wholesale & retail | 2025 |
| Timeologie Ltd | Information & communication | 2026 |
| Timo Fresh Ltd | Wholesale & retail | 2021 |
| Timothy Mctrusty Ltd | Education | 2025 |
| Timothy Mellor Architect Limited | Professional & scientific | 2024 |
| TIN TIN Lemon Limited | Manufacturing | 2023 |
| Tina Anarfi Limited | Health & social care | 2021 |
| Tina Group Limited | Wholesale & retail | 2023 |
| Tinamous Limited | Extraterritorial | 2015 |
| Tindalls the Stationers Limited | Wholesale & retail | 1992 |
| Tinfer AI Limited | Information & communication | 2025 |
| Tingshi Furniture Co., Ltd. | Extraterritorial | 2019 |
| Tinney Haulage & Cranes Limited | Administrative & support | 2016 |
| Tinte Creative Ltd | Professional & scientific | 2026 |
| Tiny Blue Robots Limited | Information & communication | 2012 |
| Tipco Tools Limited | Manufacturing | 2025 |
| Tirion Tech Ltd | Wholesale & retail | 2024 |
| Tismarr Properties Ltd | Real estate | 2021 |
| Tita Marius Air Company Ltd | Manufacturing | 2026 |
| Titan Electrical Ltd | Construction | 2019 |
| Titan Mobile Tyres & Brakes Ltd | Wholesale & retail | 2026 |
| Titan Renewables Ltd | Energy | 2026 |
| Titancut Ltd | Manufacturing | 2025 |
| Titanium Integration Ltd | Health & social care | 2023 |
| Titanium Tutors Ltd. | Education | 2013 |
| Titchfield Enterprises Ltd | Professional & scientific | 1999 |
| Tito Cambridge Limited | Other services | 2024 |
| Titokiko Limited | Hospitality | 2011 |
| Titus Development (Cambridge) Limited | Construction | 2020 |
| TJ Kids Community Interest Company | Health & social care | 2011 |
| TJ Welding & Fabrication Ltd | Manufacturing | 2020 |
| TJB Principal Group Ltd | Real estate | 2026 |
| TJC Developments Cambridge Ltd | Construction | 2023 |
| TJH Holdings Limited | Professional & scientific | 2018 |
| TJM (Essex) Limited | Real estate | 2007 |
| TJM (London) LLP | | 2007 |
| TJM Management Limited | Real estate | 2003 |
| TJS Radiology Limited | Health & social care | 2022 |
| TJW Plant & Groundworks Ltd | Construction | 2010 |
| TK Bintang Hiburan Ltd | Wholesale & retail | 2025 |
| TKB4289 & Co Ltd | Hospitality | 2019 |
| TL Composite Ltd | Manufacturing | 2023 |
| Tl.Conv 767 Ltd | Manufacturing | 2024 |
| TLG Partnership Ltd | Professional & scientific | 2019 |
| Tltaerospace Ltd | Manufacturing | 2024 |
| TM Ecology Ltd | Professional & scientific | 2022 |
| Tmas Foods Ltd | Wholesale & retail | 2021 |
| TMC Specialist Cleaning Limited | Administrative & support | 2017 |