| Thekenilworthcentre | Arts & recreation | 2011 |
| Thialh Limited | Wholesale & retail | 2017 |
| Thickthorn Mews Management Company Limited | Households | 1985 |
| Thin Slice Software Ltd | Information & communication | 2015 |
| Think PDW Group Limited | Financial services | 2025 |
| Think Talk Thrive Ltd | Professional & scientific | 2023 |
| Thistledown Cowford Farms Limited | Agriculture & fishing | 2018 |
| Thistledown Developments Limited | Construction | 1997 |
| Thistledown Farms Limited | Agriculture & fishing | 1997 |
| Thistledown Investments Limited | Financial services | 1998 |
| Thistledown Properties Limited | Real estate | 1996 |
| Thompson Burrows Limited | Real estate | 2014 |
| Thornby Legal Limited | Professional & scientific | 2026 |
| Thorogood Group Limited | Professional & scientific | 2018 |
| Thoughtful Creations Ltd | Professional & scientific | 2021 |
| Thousand Spread (Hong Kong) Limited | Extraterritorial | 2017 |
| THP Consultants Ltd | Professional & scientific | 2024 |
| Threadmaster Gauges Limited | Manufacturing | 1977 |
| Three One Nine Ltd | Wholesale & retail | 2019 |
| Thrive Ecommerce Limited | Information & communication | 2021 |
| Thywill Ltd | Hospitality | 2021 |
| Tian Jian Motorcycle Accessories Co., Ltd | Administrative & support | 2023 |
| Tianhe Technology Ltd | Wholesale & retail | 2023 |
| Tianjin Yuantai Derun International Co., Ltd. | Administrative & support | 2023 |
| Tianyu International Engineering Machinery Co., Ltd | Manufacturing | 2023 |
| Tiger Network Limited | Information & communication | 2018 |
| Tigh FEN Limited | Hospitality | 2025 |
| Timber Frame Engineering Services Ltd | Professional & scientific | 2009 |
| Time 4 Efficiency Limited | Professional & scientific | 2023 |
| Time for ME (of Kenilworth) Ltd | Health & social care | 2016 |
| Time for Tea Kenilworth Limited | Hospitality | 2008 |
| Time for Tea Prossers Limited | Hospitality | 2022 |
| Time to Admire Ltd | Wholesale & retail | 2020 |
| Timothy Cooper Estates Ltd | Real estate | 2025 |
| Timothy Holding Co., Ltd | Extraterritorial | 2012 |
| Tisdale Finance Limited | Real estate | 1970 |
| Tisdale Rise (Three Blocks) Limited | Households | 2018 |
| Tjbl Media Ltd | Information & communication | 2026 |
| TMS Brand Company Ltd | Wholesale & retail | 2026 |
| TMW Builders Ltd | Construction | 2025 |
| TMW Management Limited | Professional & scientific | 2012 |
| Tofu and Bloom Limited | Manufacturing | 2025 |
| Tomartacus Limited | Arts & recreation | 2016 |
| Tong Orange Auto Parts Co., Ltd | Wholesale & retail | 2023 |
| Tongsheng International Trade Ltd | Extraterritorial | 2024 |
| Tony Goodman Systems Consulting Limited | Information & communication | 2014 |
| Tooling Intelligence Build Centre Ltd | Administrative & support | 2018 |
| Tooling Intelligence Holdings Limited | Financial services | 2018 |
| Tooling Intelligence Limited | Administrative & support | 2007 |
| Tooling Intelligence Services Limited | Administrative & support | 2018 |
| Top Nosh Food Ltd | Wholesale & retail | 2007 |
| Top Vision Machinery Co. Ltd | Administrative & support | 2021 |
| Topia Group Limited | Financial services | 2025 |
| Topton Leisure Collection Ltd | Extraterritorial | 2014 |
| Topuri Co., Ltd | Extraterritorial | 2017 |
| Torri Ltd | Professional & scientific | 2012 |
| Tortola Sage Arawak Ltd | Extraterritorial | 2017 |
| Total Itil Solutions Ltd | Professional & scientific | 2024 |
| Touchwood Projects Limited | Construction | 2016 |
| Toughweb Ltd | Information & communication | 2010 |
| Towards Outstanding Leadership Limited Liability Partnership | | 2016 |
| Town and Country Training Limited | Extraterritorial | 2024 |
| Toyar Co., Ltd | Administrative & support | 2021 |
| Toyo Valve Co., Limited | Extraterritorial | 2018 |
| Trade Mark Logistics Limited | Transport & logistics | 2008 |
| Trades by Ross Ltd | Other services | 2023 |
| Traditional Livestock Foundation Limited | Agriculture & fishing | 2010 |
| Transcrozz Ltd | Extraterritorial | 2018 |
| Transmission Excellence Limited | Energy | 2015 |
| Transport Decarbonisation Limited | Professional & scientific | 2025 |
| Travel Buddies UK Limited | Administrative & support | 2017 |
| Tredomen Farm Ltd | Agriculture & fishing | 2021 |
| Tree Survey Associates Limited | Extraterritorial | 2005 |
| Trek Precision Industry Co., Ltd | Wholesale & retail | 2019 |
| Trend Fashion Co, Ltd | Administrative & support | 2022 |
| Trevis Holdings Limited | Financial services | 2023 |
| Triangle Nurseries Limited | Education | 1999 |
| Trimcraft Engineering Ltd | Professional & scientific | 2010 |
| Trimech Enterprise Solutions Limited | Information & communication | 1986 |
| Trimech Manufacturing Solutions Limited | Wholesale & retail | 2018 |
| Trimech UK Holdings Limited | Financial services | 2022 |
| Triostack Ltd | Information & communication | 2025 |
| Tripleset Productions Ltd | Arts & recreation | 2022 |
| Tripod Designs Ltd | Professional & scientific | 2026 |
| Tristone Flowtech (UK) Limited | Manufacturing | 2017 |
| Trudson (Wellington) Limited | Real estate | 2006 |
| Trudson Limited | Financial services | 2002 |
| True Romantica Bridal Limited | Wholesale & retail | 2012 |
| True Way Export Co., Ltd | Administrative & support | 2022 |
| Truecaller Limited | Information & communication | 2024 |
| Truly Content Limited | Professional & scientific | 2014 |
| Trustele Holdings Limited | Administrative & support | 2013 |
| Tsbb Ltd | Professional & scientific | 2010 |
| Tss&P Limited | Wholesale & retail | 1997 |
| TSY Industrial Technology Group Co., Ltd | Administrative & support | 2025 |
| TT Travel Limited | Financial services | 2011 |
| Tulip Planning Solutions Ltd | Professional & scientific | 2025 |
| Tulip Tree Court Residents Management Company Limited | Households | 2026 |
| TUO Yuan Trading Co., Ltd | Administrative & support | 2023 |
| Turkish Barber Kenilworth Ltd | Other services | 2024 |