| Theye Limited | Wholesale & retail | 2009 |
| Thieme KPX Limited | Manufacturing | 1999 |
| Think Forensics Limited | Education | 2006 |
| Think Hitech Limited | Information & communication | 2020 |
| Think Smart Security Limited | Administrative & support | 2024 |
| This Candy Sweet Company Limited | Wholesale & retail | 2022 |
| Thistle and Olive Holdings Limited | Construction | 2025 |
| Thlc Limited | Hospitality | 2025 |
| Thomas Brown Engineering Limited | Manufacturing | 2004 |
| Thomas Crapper and Company,Limited | Manufacturing | 1904 |
| Thomas Hayden Ltd | Arts & recreation | 2016 |
| Thomas Lomax Construction Ltd | Construction | 2011 |
| Thomas Rodley Engineering Limited | Professional & scientific | 2018 |
| Thomas Shepherdson Limited | Agriculture & fishing | 2007 |
| Thompson Neuro Assessments Ltd | Health & social care | 2025 |
| Thordale Limited | Construction | 2009 |
| Thorjon 1 | Administrative & support | 2014 |
| Thorjon 2 | Administrative & support | 2014 |
| Thorjon 3 | Administrative & support | 2014 |
| Thorjon 4 | Administrative & support | 2014 |
| Thorjon 5 | Administrative & support | 2014 |
| Thorncliffe Farm Shop Limited | Wholesale & retail | 2006 |
| Thorne Road Ltd | Wholesale & retail | 2026 |
| Thornepharma Ltd | Health & social care | 2022 |
| Thornfield Industries Ltd | Information & communication | 2022 |
| Thornton & Ross Limited | Manufacturing | 1922 |
| Thornton Jones Holdings Limited | Financial services | 2025 |
| Thorntons Joinery and Construction Ltd | Construction | 2025 |
| Thorpe & King Plastering Contractors Ltd | Construction | 2008 |
| Thorpe House Specialist Adult Mental Health Unit Limited | Health & social care | 2004 |
| Thread Connect Ltd | Hospitality | 2024 |
| Three Beans Cafe Ltd | Hospitality | 2025 |
| Three Days Consultancy Ltd | Professional & scientific | 2025 |
| Three Diamonds Commercial Limited | Construction | 2016 |
| Three Fold Property Development Ltd | Real estate | 2023 |
| Three Friends Import & Export UK Limited | Wholesale & retail | 2024 |
| Three Oaks Assets Ltd | Real estate | 2025 |
| Three One Trading Ltd | Wholesale & retail | 2024 |
| Threesixty Talent Limited | Administrative & support | 2023 |
| Thrifty Treasures Ltd | Wholesale & retail | 2025 |
| Thrive (SE) C.I.C. | Education | 2025 |
| Thrive Beyond Abuse CIC | Other services | 2026 |
| Thrive Essence Ltd | Health & social care | 2025 |
| Thriving Homes Ltd | Health & social care | 2022 |
| Thunder Bridge Dogs Ltd | Other services | 2023 |
| Thunderstruck Limited | Extraterritorial | 2014 |
| Thurnscoe Hall Mews Management Company Ltd | Construction | 2022 |
| TI Asset Management Ltd | Real estate | 2021 |
| Tian Shipping Export Ltd | Wholesale & retail | 2023 |
| Tibbit and Smythe Limited | Manufacturing | 2025 |
| Tichila Limited | Health & social care | 2023 |
| Ticketview Limited | Wholesale & retail | 2026 |
| Tidal Bay Veterinary Services Ltd | Financial services | 2022 |
| Tidal Financial Services Ltd | Financial services | 2022 |
| Tieronemodels Limited | Arts & recreation | 2025 |
| Tierra Natural Stone Group Limited | Wholesale & retail | 2024 |
| Tiffany Ryder Limited | Construction | 2024 |
| Tiger International Limited | Wholesale & retail | 2011 |
| Tiger Moth Experience Limited | Other services | 2012 |
| Tiger Security Ltd | Administrative & support | 2024 |
| Tighe Property and Developments Ltd | Construction | 2025 |
| Tilldex Automotive Limited | Wholesale & retail | 2015 |
| TIM Brook Utilities Ltd | Construction | 2010 |
| TIM CBS Limited | Professional & scientific | 2026 |
| TIM Marsella Limited | Professional & scientific | 2005 |
| TIM Reilly Music Limited | Information & communication | 2013 |
| TIM Thornton Consulting Ltd | Professional & scientific | 2022 |
| Timber Specialists (Holdings) Limited | Financial services | 2018 |
| Timber Specialists (Property) Limited | Wholesale & retail | 2012 |
| Timber Specialists (Sheffield) Limited | Wholesale & retail | 1998 |
| Timber Specialists Humber Limited | Wholesale & retail | 2000 |
| Timber Specialists Limited | Wholesale & retail | 2000 |
| Timberbuilduk Ltd | Construction | 2019 |
| Timberwood Management Company Limited | Real estate | 2000 |
| Time for YOU Spa & Beauty Ltd | Other services | 2021 |
| Time Music Ltd | Arts & recreation | 2012 |
| Timelord Education Ltd | Education | 2013 |
| Times Trading Ltd | Wholesale & retail | 2023 |
| Timma Ltd | Construction | 2023 |
| TIN Box Pizza Limited | Hospitality | 2026 |
| Tinga Creations Limited | Wholesale & retail | 2022 |
| Tinstransport Services and Road 2025 Ltd | Transport & logistics | 2025 |
| Tiny Property Investments Ltd | Real estate | 2024 |
| TIP Top Wares Ltd | Wholesale & retail | 2022 |
| Tipple Group Ltd | Manufacturing | 2026 |
| Tipsy COW (Skelmanthorpe) Limited | Hospitality | 2019 |
| Titan Cricket Ltd | Manufacturing | 2023 |
| Titan PS Management Limited | Professional & scientific | 2023 |
| Titan PUB Solutions Limited | Hospitality | 2013 |
| Titan Risk Management Ltd | Administrative & support | 2018 |
| Titanium Waves UK Ltd | Wholesale & retail | 2021 |
| Titantech Innovations Limited | Information & communication | 2024 |
| Tivoli Travel (Cleckheaton) Limited | Administrative & support | 2024 |
| Tivoli Travel (Denby Dale) Limited | Administrative & support | 2024 |
| Tivoli Travel (Holmfirth) Limited | Administrative & support | 2019 |
| Tivoli Travel Limited | Administrative & support | 2015 |
| TJ Search & Selection Limited | Administrative & support | 2020 |
| TJ Thai Japanese Restaurant Limited | Hospitality | 2017 |
| TJI Associates Limited | Professional & scientific | 2023 |
| TJN Properties Ltd | Real estate | 2024 |