| Think Like a Pony CIC | Education | 2013 |
| Think Pacific Limited | Arts & recreation | 2006 |
| Think Properties Solutions Limited | Real estate | 2023 |
| Think Real Limited | Professional & scientific | 2019 |
| Think Site Services Ltd | Construction | 2023 |
| Think SO Limited | Professional & scientific | 2006 |
| Think Tech Resourcing Limited | Professional & scientific | 2022 |
| Think Traffic Management Ltd | Administrative & support | 2020 |
| Thinking Digital Strategy Limited | Professional & scientific | 2016 |
| Thinking Monsters Ltd | Administrative & support | 2025 |
| Thinknd: Inclusive Solutions Ltd | Professional & scientific | 2025 |
| Thinkprintsolutions Ltd. | Administrative & support | 2014 |
| Thinksentient Limited | Information & communication | 2008 |
| Thinksmart Marketing Limited | Professional & scientific | 2016 |
| Thinksyntra Portals Limited | Information & communication | 2025 |
| Thinktribal Limited | Information & communication | 2019 |
| Third Coast Ltd | Information & communication | 2018 |
| Third EYE Property Limited | Real estate | 2019 |
| Third Fundamental Ltd | Information & communication | 2019 |
| Third Life Ltd | Health & social care | 2017 |
| Third Official Ltd | Wholesale & retail | 2025 |
| Thirsk Solutions Ltd | Professional & scientific | 2019 |
| Thirteen Barbers Ltd | Other services | 2019 |
| Thirteen Four Limited | Wholesale & retail | 2020 |
| Thirty-Four Leeds Limited | Hospitality | 2023 |
| Thirty-Six Leeds Limited | Hospitality | 2021 |
| Thirtyone Sigma Limited | Information & communication | 2017 |
| This Architecture Limited | Professional & scientific | 2023 |
| This Green Moon Limited | Hospitality | 2015 |
| This IS CGI Limited | Transport & logistics | 2023 |
| This IS Distorted Limited | Information & communication | 2013 |
| This IS My: Body Limited | Health & social care | 2015 |
| This IS My: Healthcare Holdings Limited | Health & social care | 2018 |
| This IS My: Limited | Health & social care | 2010 |
| This IS My: Sports Medicine Limited | Health & social care | 2014 |
| This IS My: Ultrasound Services Limited | Health & social care | 2016 |
| This IS Serious. Ltd | Hospitality | 2025 |
| This IS Tight Ltd | Professional & scientific | 2016 |
| This IS Tomoro Ltd | Professional & scientific | 2018 |
| This IS Vision Ltd | Real estate | 2007 |
| This IS WHO WE ARE Ltd | Other services | 2023 |
| This IS Yorkshire Beauty Ltd | Administrative & support | 2024 |
| Thisisallgood Limited | Professional & scientific | 2006 |
| Thisldome LLP | | 2013 |
| Thisolutions Limited | Information & communication | 2009 |
| Thistle & Rose Productions Limited | Arts & recreation | 2019 |
| Thistle and Rose Concepts Ltd | Construction | 2019 |
| Thistle Print Limited | Manufacturing | 2003 |
| Thisyear Limited | Real estate | 2013 |
| Thjb Beauty Limited | Administrative & support | 2022 |
| THL Realisation Limited | Health & social care | 2017 |
| THM Estates Limited | Real estate | 2023 |
| Thomas & Whitley Limited | Manufacturing | 2012 |
| Thomas Alexander Consulting Limited | Other services | 2020 |
| Thomas Ambler & Sons Limited | Professional & scientific | 1948 |
| Thomas and Forrest Maintenance Limited | Administrative & support | 2021 |
| Thomas and Ginger Limited | Wholesale & retail | 2026 |
| Thomas Balmforth Music Ltd | Information & communication | 2019 |
| Thomas Black.Limited | Real estate | 1928 |
| Thomas Carr Limited | Manufacturing | 1907 |
| Thomas Clifford Ltd | Wholesale & retail | 2023 |
| Thomas Coombs Limited | Professional & scientific | 2012 |
| Thomas Coombs Wealth Management Limited | Extraterritorial | 2019 |
| Thomas Elizabeth Investments Limited | Other services | 2025 |
| Thomas Grant Digital Limited | Information & communication | 2018 |
| Thomas Hardy's (Horsforth) Limited | Hospitality | 2026 |
| Thomas Hardy's Limited | Hospitality | 2026 |
| Thomas Harvey Legal Limited | Professional & scientific | 2023 |
| Thomas Henry Mallaband Limited | Health & social care | 2004 |
| Thomas Judd-Cooper Limited | Information & communication | 2022 |
| Thomas Meneaud Limited | Real estate | 2024 |
| Thomas Portas Limited | Wholesale & retail | 2013 |
| Thomas Samuel Limited | Construction | 2010 |
| Thomas Street Business Centre Limited | Real estate | 2012 |
| Thomas Taylor Real Estate Ltd | Real estate | 2018 |
| Thomasons Funeral Services Limited | Other services | 2003 |
| Thompson & Co (Great Horton) Limited | Wholesale & retail | 1943 |
| Thompson & Wright Ltd. | Hospitality | 2021 |
| Thompson Actuarial Ltd | Professional & scientific | 2022 |
| Thompson Green & Co. Limited | Real estate | 1948 |
| Thompson Technik (Newcastle) Limited | Water & waste | 1993 |
| Thompson Transport Consultancy Ltd | Other services | 2022 |
| Thompson-Automation Ltd | Professional & scientific | 2015 |
| Thompsonco Limited | Administrative & support | 2018 |
| Thompsons Interior Solutions Ltd | Construction | 2025 |
| Thomson Welding Limited | Manufacturing | 2020 |
| Thongpoon Therapy Ltd | Health & social care | 2023 |
| Thor Energy Leeds Ltd | Energy | 2023 |
| Thor Storage Solutions Limited | Transport & logistics | 2022 |
| Thorax Medical and Legal Services Ltd | Professional & scientific | 2014 |
| Thordisa Limited | Information & communication | 2021 |
| Thorgreen Holdings Limited | Information & communication | 2023 |
| Thornaway Properties Ltd | Real estate | 2025 |
| Thornbridge Joiner Ltd | Construction | 2023 |
| Thornbury Properties Bradford Ltd | Real estate | 2021 |
| Thorne Management Company Limited | Administrative & support | 2016 |
| Thorner Building Services Ltd | Construction | 2024 |
| Thorner Flooring Services Limited | Construction | 2023 |
| Thorner Lane Limited | Hospitality | 2021 |
| Thornes House (Management) Ltd | Real estate | 2011 |