| Thornham Car Sales Limited | Wholesale & retail | 2010 |
| Thornhill Fenwick & Co. | Agriculture & fishing | 1931 |
| Thornhvac Limited | Professional & scientific | 1993 |
| Thorniehurst Ltd | Construction | 2018 |
| Thornlea Court (Maintenance) Limited | Administrative & support | 1971 |
| Thornleigh Food & Wine Ltd | Wholesale & retail | 2023 |
| Thornley Family Investments Limited | Extraterritorial | 2013 |
| Thornley LS Limited | Extraterritorial | 2010 |
| Thornton & Partners Limited | Professional & scientific | 2026 |
| Thornton Bar Ltd | Hospitality | 2023 |
| Thornton Commercial Property Services Ltd | Construction | 2016 |
| Thornton Court Properties Limited | Real estate | 2022 |
| Thornton Heritage Crafts Ltd | Manufacturing | 2025 |
| Thornton Property Investment Group Limited | Real estate | 2024 |
| Thorntons Barbers Ltd | Other services | 2021 |
| Thoroughbred Business Management Limited | Professional & scientific | 2009 |
| Thorpe Company Inc Ltd | Real estate | 2024 |
| Thorpe Estates Limited | Real estate | 2008 |
| Thorpe Joinery & Construction Ltd | Construction | 2023 |
| Thorpe Lane Precast Ltd | Manufacturing | 2009 |
| Thorpe Packaging Limited | Administrative & support | 1995 |
| Thorpe Park (Wakefield) Management Company Limited | Households | 2006 |
| Thorpe Park A2 Limited | Real estate | 2019 |
| Thorpe Park Developments Limited | Construction | 2001 |
| Thorpe Park Gardens (Leeds) Management Company Limited | Real estate | 2015 |
| Thorpe Park Holdings Limited | Financial services | 2015 |
| Thorpe Properties Yorkshire Ltd | Real estate | 2026 |
| Thorpe Property Development Limited | Real estate | 2005 |
| Thorpe Rise Developments Limited | Real estate | 2018 |
| Thortfolio Ltd | Education | 2022 |
| Thos. Bentley & SON Limited | Real estate | 1965 |
| Thos. C. Fawcett Limited | Arts & recreation | 1974 |
| Thos. Dawes & SON Limited | Manufacturing | 2010 |
| Thought Bubble Festival Limited | Arts & recreation | 2010 |
| Thrayam Ltd | Hospitality | 2021 |
| Threadox Ltd | Wholesale & retail | 2023 |
| Threads Apparel UK Ltd | Transport & logistics | 2023 |
| Threads of Asia Ltd | Wholesale & retail | 2024 |
| Threads&Co Ltd | Wholesale & retail | 2025 |
| Threadsbyrani Ltd | Wholesale & retail | 2025 |
| Threadworks Textiles Ltd | Wholesale & retail | 2025 |
| Threatsense AI UK Limited | Information & communication | 2025 |
| Three Beams Thinking Ltd | Other services | 2023 |
| Three Cottages Cafe Ltd | Hospitality | 2018 |
| Three D Visions Ltd | Professional & scientific | 2022 |
| Three Five Trading Limited | Real estate | 2013 |
| Three Horseshoes (Leeds Road) Ltd | Hospitality | 2023 |
| Three Little Birds Investments | Financial services | 2020 |
| Three Oaks Management Company Limited | Households | 2001 |
| Three Pegasus Group Ltd | Extraterritorial | 2024 |
| Three Rings Consulting Limited | Information & communication | 2002 |
| Three Shinning Stars Limited | Health & social care | 2013 |
| Three SIX Zero Manufacture and Installation Ltd | Construction | 2013 |
| Three Twenty Search Limited | Administrative & support | 2022 |
| Three Valleys Access Ltd | Households | 2021 |
| Three-Yes Ltd | Information & communication | 2012 |
| THREE33 Ventures Ltd | Wholesale & retail | 2022 |
| Threes a Crowd (York) Ltd | Extraterritorial | 2024 |
| Threetenseven Ltd | Administrative & support | 1999 |
| Threetwo Financial Ltd | Financial services | 2025 |
| Threshfield Catering Supplies Limited | Wholesale & retail | 2010 |
| Threshfield Holdings Limited | Financial services | 2023 |
| Threshold Endurance Ltd | Information & communication | 2026 |
| Threshold Marketing Limited | Professional & scientific | 2025 |
| Threshold Property Ltd | Real estate | 2025 |
| Thrift IT Gift IT Ltd | Wholesale & retail | 2025 |
| Thriftysites Group Ltd | Information & communication | 2025 |
| Thrill of the Grill Leeds Ltd | Hospitality | 2020 |
| Thrive Again CIC | Education | 2025 |
| Thrive Again Therapy Ltd | Health & social care | 2025 |
| Thrive Alive Psychotherapy Ltd | Health & social care | 2022 |
| Thrive Bulk Holdings Ltd | Wholesale & retail | 2025 |
| Thrive Commercial Finance Ltd | Financial services | 2022 |
| Thrive Credit Hire Ltd | Administrative & support | 2024 |
| Thrive Data Consultancy Limited | Information & communication | 2025 |
| Thrive Finance Solutions Limited | Professional & scientific | 2026 |
| Thrive Integrative Medical Clinic Ltd | Health & social care | 2022 |
| Thrive Project Management Limited | Professional & scientific | 2020 |
| Thrive Training Ltd | Professional & scientific | 2024 |
| Thrive With US Ltd | Hospitality | 2021 |
| Thrivoai AI UK Limited | Information & communication | 2026 |
| Thrivoai Limited | Information & communication | 2026 |
| Thrown in Stone Limited | Manufacturing | 2013 |
| Throxenby Properties Limited | Real estate | 2023 |
| THS Fashion Limited | Wholesale & retail | 2023 |
| Thubrons Construction Consultants Limited | Construction | 2021 |
| Thulasi Limited | Health & social care | 2019 |
| Thunkd Games Ltd | Information & communication | 2018 |
| Thunkd Ltd | Information & communication | 2011 |
| Thurleigh Ltd | Professional & scientific | 2023 |
| Thursday’S Child Licencing Limited | Professional & scientific | 2023 |
| Thybork Care Ltd | Health & social care | 2025 |
| TIA Business Consultancy Limited | Professional & scientific | 2016 |
| Tia/Tia Ltd | Wholesale & retail | 2023 |
| Tiago Maintenance Limited | Construction | 2021 |
| Tiaj Property Ltd | Real estate | 2024 |
| Tiamel Properties Ltd | Real estate | 2019 |
| Tian Tian Lucky Choice Limited | Hospitality | 2021 |
| Tibbie& Ltd | Wholesale & retail | 2025 |
| Tibby Works Ltd | Households | 2023 |