| Theskincoach Ltd | Other services | 2023 |
| Thetechcreators Ltd | Information & communication | 2023 |
| Thetidytouch Ltd | Other services | 2023 |
| They'Re Behind YOU Productions Limited | Wholesale & retail | 2021 |
| Thimyl (UK) Ltd | Health & social care | 2021 |
| Thind Construction Works Limited | Construction | 2017 |
| Thind Courier Services Limited | Transport & logistics | 2016 |
| Thinkglobal Properties Ltd | Real estate | 2025 |
| Thinkteq Technology Ltd | Wholesale & retail | 2023 |
| Third Space Collective Ltd | Information & communication | 2025 |
| Thirdwaveict Ltd | Information & communication | 2019 |
| Thirteen Holdings Unlimited | Administrative & support | 2017 |
| THIRTEEN57 Ltd | Health & social care | 2011 |
| Thirtythree-It Limited | Information & communication | 2014 |
| THJ Global Properties Ltd | Real estate | 2023 |
| Thoba Enterprise Ltd | Transport & logistics | 2026 |
| Thomas & COE Limited | Professional & scientific | 2022 |
| Thomas Associates (Wolverhampton) Limited | Professional & scientific | 2011 |
| Thomas Baugh Media Limited | Information & communication | 2012 |
| Thomas Flowers Limited | Wholesale & retail | 2025 |
| Thomas Harvey Estate Agents Limited | Real estate | 2024 |
| Thomas Mann Holdings Limited | Financial services | 2018 |
| Thomas Skidmore & SON | Administrative & support | 1940 |
| Thomas Sonography Ltd | Professional & scientific | 2016 |
| Thomason Engineering Solutions Ltd | Administrative & support | 2014 |
| Thompson Audio Visual Communications Limited | Administrative & support | 2000 |
| Thompson Automotive Vehicle Consultancy Limited | Administrative & support | 2008 |
| Thompson AVC (TFL) Ltd | Administrative & support | 2010 |
| Thompson DC Limited | Administrative & support | 2014 |
| Thompson Meredith Associates Ltd | Professional & scientific | 1996 |
| Thompson Unified Communications Ltd | Information & communication | 2016 |
| Thomson Straw & Haulage Limited | Agriculture & fishing | 2015 |
| Thorark Holdings Ltd | Financial services | 2025 |
| Thoritra Ltd | Administrative & support | 2021 |
| Thorley Palombo Limited | Real estate | 2024 |
| Thornbury Accountants Ltd | Professional & scientific | 2014 |
| Thorne International Boiler Services Limited | Manufacturing | 1973 |
| Thornebridge Acquisitions and Lettings Ltd | Real estate | 2023 |
| Thornes Legal Limited | Professional & scientific | 2013 |
| Thorneycroft Modular Construction Company Limited | | 1976 |
| Thornton Claverley Independent Financial Advisers Limited | Financial services | 1999 |
| Thousand Face Limited | Wholesale & retail | 2015 |
| Threat Fence Ltd | Wholesale & retail | 2026 |
| Three Black Cats and a Crocodile Ltd | Manufacturing | 2017 |
| Three Brothers Collective Ltd | Wholesale & retail | 2025 |
| Three Cups Ltd | Hospitality | 2026 |
| Three KAY Properties Limited | Construction | 2003 |
| Three Lillies Healthcare Ltd | Health & social care | 2025 |
| Three Peaks Logistics Limited | Wholesale & retail | 2026 |
| Three Pines Automotive Ltd | Wholesale & retail | 2025 |
| Three Pines Building Co. Limited | Construction | 1972 |
| Three Pines Estates Limited | Real estate | 2021 |
| Three Pines Group Limited | Financial services | 2025 |
| Three Pines Holdings Limited | Financial services | 2021 |
| Three Pines Management Limited | Real estate | 2021 |
| Three Seven Investment Group Ltd | Financial services | 2023 |
| Three Tuns Contractor Limited | | 2016 |
| Threefab Ltd | Health & social care | 2022 |
| Threesixty Holdco 8 Limited | Financial services | 2023 |
| Threesixty Investco 8 Limited | Financial services | 2023 |
| Thrive Alive Limited | Information & communication | 2017 |
| Thrive Bestie Ltd | Extraterritorial | 2025 |
| Thriveplus Recruitment Ltd | Administrative & support | 2020 |
| Through This Therapy Ltd. | Health & social care | 2025 |
| Thryvix Ltd | Wholesale & retail | 2025 |
| Thryxnara Ltd | Administrative & support | 2021 |
| Thunderbolt Clothing Limited | Manufacturing | 2011 |
| Tiap Investment Ltd | Real estate | 2024 |
| TIC Engineering Services Limited | Manufacturing | 2018 |
| Tick Tech Emipire Ltd | Wholesale & retail | 2025 |
| Tiddan Foods Limited | Manufacturing | 2021 |
| Tideway House Ltd | Real estate | 2025 |
| Tidmarsh & Co. Limited | Extraterritorial | 2015 |
| Tidmarsh Estate Agents Limited | Extraterritorial | 2015 |
| Tidmarsh Group Limited | Extraterritorial | 2015 |
| TIE My Turban Limited | Other services | 2016 |
| Tierce Properties Ltd | Real estate | 2021 |
| Tiffany Clark Hair Ltd | Other services | 2024 |
| Tiffu's Dining Ltd | Hospitality | 2023 |
| Tiger EYE Hospitality Ltd | Arts & recreation | 2023 |
| Tiger Promotions Agency Limited | Administrative & support | 2019 |
| Tigerfleck Ltd | Real estate | 2025 |
| TIJ Limited | Health & social care | 2021 |
| TIJ Property Management Ltd | Real estate | 2025 |
| Tijite Ltd | Agriculture & fishing | 2024 |
| Tikartyzatok Ltd | Wholesale & retail | 2025 |
| Tikucooperation & Team Ltd | Construction | 2025 |
| Tiley Smith Limited | Professional & scientific | 2015 |
| TIM Fast-Food Ltd | Hospitality | 2025 |
| TIM Wilde MMA Ltd | Arts & recreation | 2014 |
| Timber KIT Solutions Ltd | Manufacturing | 2008 |
| Time IS the New Money Limited | Real estate | 2014 |
| Timeless & Flow Investments Ltd. | Real estate | 2021 |
| Timetrics Ltd | Professional & scientific | 2025 |
| Timewise Recruitment Ltd | Administrative & support | 2024 |
| Timmy Pharell Entertainment Limited | Arts & recreation | 2022 |
| Timothy's Toy Box Limited | Wholesale & retail | 2020 |
| Tinamwari Ltd | Administrative & support | 2019 |
| Tinsleynet Limited | Information & communication | 2014 |
| Tiny Toez Childrens Day Nurseries Limited | Education | 2013 |