| Thesoxialpath Ltd | Information & communication | 2025 |
| Thespace Consulting Ltd | Professional & scientific | 2023 |
| Thess Collection Limited | Financial services | 2026 |
| Thestitchedsociety Ltd | Manufacturing | 2025 |
| Thesweetsmellco Ltd | Manufacturing | 2023 |
| Theta Constructive Limited | Information & communication | 2007 |
| Theta Electrical Limited | Construction | 2023 |
| Thetechresort Ltd | Wholesale & retail | 2025 |
| Thetford Trustee LLP | | 2009 |
| Thevoipshop Limited | Extraterritorial | 2012 |
| Theweb.Dev Ltd | Information & communication | 2023 |
| Thewellnessguys Limited | Manufacturing | 2025 |
| They Ripped ME OFF Ltd | Financial services | 2019 |
| Thghlh Ltd | Arts & recreation | 2021 |
| Thiara Estate Agents Limited | Real estate | 2016 |
| Thiara Food & OFF Licence Ltd | Wholesale & retail | 2017 |
| Thiara Ltd | Health & social care | 2008 |
| Thiara Power Engineers Ltd | Manufacturing | 2022 |
| Thimble Fabrics & Crafts Limited | Wholesale & retail | 2026 |
| Thimble's Fabrics & Crafts Limited | Manufacturing | 2018 |
| Thimble's Online Limited | Wholesale & retail | 2018 |
| Thimbles Alteration Limited | Professional & scientific | 2023 |
| Thimble’S Fabric & Craft Limited | Wholesale & retail | 2021 |
| Thimble’S Online (U.K.) Limited | Wholesale & retail | 2021 |
| Thin Client Shop Limited | Wholesale & retail | 2014 |
| Thind Midlands Ltd | Transport & logistics | 2022 |
| Think Care Services Ltd | Health & social care | 2022 |
| Think Plus INK Limited | Arts & recreation | 2008 |
| Think POS Limited | Professional & scientific | 2018 |
| Think Strategic Alliances Ltd | Information & communication | 2023 |
| Thinking Digital Agency Ltd | Professional & scientific | 2015 |
| Thinking Focus Games Ltd | Professional & scientific | 2017 |
| Thinkit Solutions Limited | Information & communication | 2007 |
| Thinkmaths Academy Limited | Education | 2025 |
| Thiravi Ltd | Financial services | 2025 |
| Third Dimension Manufacturing Ltd | Manufacturing | 2010 |
| Third Generation Business Services Limited | Professional & scientific | 2011 |
| Third Property Ltd | Real estate | 2020 |
| Third Space Mediation Ltd | Professional & scientific | 2025 |
| Third Space Solutions Limited | Administrative & support | 2018 |
| Thirlby Skilful Ltd | Transport & logistics | 2014 |
| Thirsty H2O Ltd | Wholesale & retail | 2021 |
| Thirsty Holding Limited | Hospitality | 2022 |
| Thirteen House Ltd | Real estate | 2024 |
| Thirteen Plus Limited | Hospitality | 2024 |
| Thiru Builders Limited | Construction | 2025 |
| Thirusi Ltd | Wholesale & retail | 2025 |
| This FAN Girl CIC | Information & communication | 2018 |
| This Girl I Know Ltd | Professional & scientific | 2017 |
| This Works EOR Services Limited | Administrative & support | 2022 |
| This'A Coaching and Consultancy Ltd | Professional & scientific | 2021 |
| Thistle Close Management Limited | Households | 2023 |
| Thistleburrow Ltd | Health & social care | 2020 |
| Thistledome Consulting Ltd | Professional & scientific | 2018 |
| Thiyaab Ltd | Wholesale & retail | 2024 |
| THJ Systems Ltd | Information & communication | 2007 |
| Thobe of Asala Limited | Wholesale & retail | 2025 |
| Tholthorpe Solutions Ltd | Hospitality | 2015 |
| Thomans Group Limited | Wholesale & retail | 2023 |
| Thomas & Sons (Construction) Limited | Construction | 2008 |
| Thomas & Sons (Nottingham) Holdings Limited | Professional & scientific | 2022 |
| Thomas & Sons Nottingham Limited | Extraterritorial | 2016 |
| Thomas Bayley and Company Limited | Real estate | 1931 |
| Thomas Brothers Property Ltd | Real estate | 2020 |
| Thomas Cassie & Sons (Leicester) Ltd | Construction | 2012 |
| Thomas Davies Services Limited | Transport & logistics | 2017 |
| Thomas Firth,Limited | Wholesale & retail | 1932 |
| Thomas Hirst Electrical Ltd | Extraterritorial | 2015 |
| Thomas Lowe Joinery Limited | Extraterritorial | 1963 |
| Thomas Lyons PUB Company Limited | Hospitality | 2016 |
| Thomas Morgan Cleaning Services Limited | Real estate | 2024 |
| Thomas Percy Construction Limited | Construction | 2012 |
| Thomas S Wilson Limited | Construction | 2015 |
| Thomas Smith Studio Limited | Arts & recreation | 2015 |
| Thomas Taad UK Ltd | Other services | 2022 |
| Thomas White (Leicester) Limited | Manufacturing | 1950 |
| Thomson & Taylor (Brooklands) Limited | Wholesale & retail | 1973 |
| Thor IT Ltd | Information & communication | 2012 |
| Thornage Victorious Ltd | Transport & logistics | 2015 |
| Thornbury Avenue Management Limited | Households | 2000 |
| Thornbury Tyler George Limited | Professional & scientific | 2024 |
| Thornby Healthcare Limited | Health & social care | 2026 |
| Thornby Topco Limited | Financial services | 2026 |
| Thorndean Limited | Manufacturing | 2021 |
| Thorney Service Centre Ltd | Wholesale & retail | 2024 |
| Thornhaugh Prestige Ltd | Construction | 2014 |
| Thornhills Logistics Ltd | Transport & logistics | 2014 |
| Thornthorpe Ltd | Wholesale & retail | 2015 |
| Thornton (Midlands) Holdings Ltd | Financial services | 2017 |
| Thorntonbury Limited | Other services | 2014 |
| Thorntree Holdings Limited | Real estate | 2025 |
| Thorpe & Brown Ltd | Manufacturing | 2014 |
| Thorpe & Phillips Properties Limited | Real estate | 2026 |
| Thorpe PUB Company Ltd | Hospitality | 2025 |
| Thorpefields Accountants Limited | Professional & scientific | 2006 |
| Thorpewell Consultancy Limited | Administrative & support | 2021 |
| Thoughtful Interiors Ltd | Professional & scientific | 2024 |
| Thpr Digital Ltd | Professional & scientific | 2014 |
| THQ Holdings Limited | Financial services | 2021 |
| Thraves Groundworks Ltd | Construction | 2020 |