| Thorne Poultry Transport Limited | Transport & logistics | 2015 |
| Thorne Regeneration Limited | Administrative & support | 2009 |
| Thorne Rugby Club Limited | Arts & recreation | 1996 |
| Thorne Supermarket Ltd | Wholesale & retail | 2025 |
| Thornemoor Agricultural Services Ltd | Construction | 2026 |
| Thornfield Technologies Ltd | Extraterritorial | 2026 |
| Thornhillhouse Ltd | Real estate | 2023 |
| Thornhurst Leisure Limited | Hospitality | 1989 |
| Thornhurst Ltd | Professional & scientific | 2021 |
| Thornmere Solutions Ltd | Professional & scientific | 2025 |
| Thornwick Property Ltd | Extraterritorial | 2026 |
| Thornwood Close Apartment Block 1 Limited | Real estate | 2005 |
| Thorpe Commercial Holdings Limited | Real estate | 2025 |
| Thorpe Moulding Technology Ltd | Financial services | 2017 |
| Thorpe Park (NS) Ltd | Real estate | 2021 |
| Thorpe Park Rentals (Lincoln) Ltd | Extraterritorial | 2024 |
| Thos,Wade's Estates,Limited | Real estate | 1956 |
| Thought Labs Limited | Education | 2024 |
| THR World Ltd | Administrative & support | 2019 |
| THR1VE Education Services Limited | Education | 2026 |
| Threaded Artistry Ltd | Manufacturing | 2024 |
| Threadsmith Apparel Ltd | Extraterritorial | 2026 |
| Three AM Activewear Ltd | Wholesale & retail | 2025 |
| Three Chies Limited | Health & social care | 2024 |
| Three Fellas Developments Ltd | Construction | 2026 |
| Three Links Property Limited | Real estate | 2026 |
| Three Lions Dining Group Ltd | Hospitality | 2020 |
| Threxley Ltd | Extraterritorial | 2026 |
| Thrive Doncaster Ltd | Health & social care | 2025 |
| Thrive Education Services Limited | Education | 2024 |
| Thrive Together Yoga & Wellness CIC | Health & social care | 2025 |
| THRIVE31 Pilates Limited | Arts & recreation | 2025 |
| Throne Wine UK Ltd | Wholesale & retail | 2025 |
| Thuring Limited | Arts & recreation | 2015 |
| Thurston Design Limited | Information & communication | 2018 |
| THY Grace Ltd | Wholesale & retail | 2024 |
| TIB Agency Ltd. | Wholesale & retail | 2015 |
| Tibeto Limited | Real estate | 2024 |
| TIBI1986 Limited | Transport & logistics | 2021 |
| Tibor Jones & Associates Limited | Arts & recreation | 2007 |
| Tibor Jones Consulting Ltd | Administrative & support | 2010 |
| Tibor Jones Management Ltd | Information & communication | 2010 |
| Tibor Jones Studio Limited | Administrative & support | 2014 |
| Tichill Wines UK Ltd | Wholesale & retail | 2025 |
| Ticketcabin Limited | Wholesale & retail | 2026 |
| Ticketingstack Limited | Financial services | 2026 |
| Tickhill Alpacas Limited | Hospitality | 2020 |
| Tickhill Business Consultancy Limited | Administrative & support | 2013 |
| Tickhill Cabs Limited | Transport & logistics | 2026 |
| Tickhill Engineering Company Limited | Manufacturing | 1964 |
| Tickhill Garage Limited | Wholesale & retail | 1983 |
| Tickhill Investments Limited | Real estate | 2023 |
| Tickhill Kennels Ltd | Agriculture & fishing | 2016 |
| Tickhill Property Maintenance Ltd | Construction | 2025 |
| Tickhill TAP Ltd | Hospitality | 2025 |
| Tickhill Trade Cars Limited | Wholesale & retail | 2017 |
| Tickled Pink (Doncaster) Limited | Wholesale & retail | 2018 |
| Tiddlywinks Pre-School (Bessacarr) Ltd | Education | 2010 |
| Tiger KW Ltd | Health & social care | 2025 |
| Tigers Autos Ltd | Wholesale & retail | 2026 |
| Tigerstyle Industries Ltd | Transport & logistics | 2018 |
| Tigger Investments Limited | Information & communication | 2005 |
| Tiina Carr Limited | Professional & scientific | 2012 |
| Tikvory Trading Ltd | Wholesale & retail | 2026 |
| Tilbury Boots FC CIC | Education | 2025 |
| Tile Holdings Limited | Wholesale & retail | 1994 |
| Tiles 'N' Bathrooms Limited | Wholesale & retail | 2004 |
| Tilewind Limited | Manufacturing | 1973 |
| Tili Safe Ltd | Information & communication | 2020 |
| Tili Safe Training Ltd | Information & communication | 2020 |
| Tilibasa Trans Ltd | Transport & logistics | 2025 |
| Tilly VON Bloom Ltd | Wholesale & retail | 2023 |
| TIM Jackson Limited | Construction | 2010 |
| TIM Richards Engineering Limited | Professional & scientific | 2023 |
| TIM Training C.I.C. | Education | 2021 |
| Timax Ltd | Transport & logistics | 2026 |
| Timber Project Solutions Ltd | Agriculture & fishing | 2013 |
| Time for Diamonds Limited | Wholesale & retail | 2004 |
| Time for YOU (North Lincs) Limited | Administrative & support | 2019 |
| Time for YOU (South Yorkshire) Limited | Other services | 2000 |
| Time Kebap Ltd | Hospitality | 2025 |
| Time OUT Rentals Ltd | Other services | 2019 |
| Time Recycling Limited | Water & waste | 2022 |
| Time to Shine (Moorends) Ltd | Wholesale & retail | 2024 |
| Time to Shine PPF & Detailing Ltd | Wholesale & retail | 2024 |
| Time to Succeed Limited | Administrative & support | 2025 |
| Timeless Nails Ltd | Other services | 2025 |
| Timesheet Solutions Limited | Information & communication | 2014 |
| Timmy Real Estate Ltd. | Real estate | 2023 |
| Timplas Ltd | Manufacturing | 2024 |
| Timroc Corporate Services Ltd | Financial services | 2020 |
| Timucin Brothers Limited | Real estate | 2020 |
| Tina Greaves Coaching Ltd | Administrative & support | 2022 |
| Tineve Limited | Wholesale & retail | 2026 |
| Tinhat LLP | | 2020 |
| Tink Belastingadvies LLP | | 2015 |
| Tinker Finch Ltd | Extraterritorial | 2026 |
| Tintwistle Investments Ltd | Administrative & support | 2013 |
| Tiny Stars Academy Limited | Administrative & support | 2025 |
| Tiny Tadpole Limited | Real estate | 2024 |