| Traban Construction Limited | Construction | 2009 |
| Track Logix Limited | Information & communication | 2022 |
| Trackwest Ltd | Construction | 2015 |
| Trade Direct (Kent) Ltd | Wholesale & retail | 2009 |
| Trade Flows International Limited | Professional & scientific | 2021 |
| Trade Paintings Services Limited | Other services | 2019 |
| Trademarc Construction Ltd | Administrative & support | 2012 |
| Trademarkfiredoors Ltd | Construction | 2020 |
| Tradesouk Group Limited | Wholesale & retail | 2020 |
| Traditional Travel Limited | Transport & logistics | 2008 |
| Traffic Signals & Electrical Installations Limited | Construction | 2005 |
| Traffic Watch (U.K) Limited | Transport & logistics | 1998 |
| Trailer Repair Direct Ltd | Manufacturing | 2026 |
| Train for Group Ltd. | Transport & logistics | 2018 |
| Traize Ltd | Real estate | 2022 |
| Tranquil Support Services Ltd | Health & social care | 2023 |
| Transfast Premier Ltd | Transport & logistics | 2025 |
| Transnet I.T. Limited | Information & communication | 2000 |
| Transport & Travel Limited | Transport & logistics | 2017 |
| Tranye Ltd | Real estate | 2021 |
| Trapped in the Web Ltd | Arts & recreation | 2020 |
| Travelley Limited | Administrative & support | 2022 |
| Travelplanners Southsea Limited | Administrative & support | 2019 |
| Traze Limited | Wholesale & retail | 2026 |
| Tregony Consultants Limited | Professional & scientific | 2017 |
| Trender Labs Limited | Information & communication | 2024 |
| Trendy Beauty Ltd | Other services | 2020 |
| Trenear Consulting Limited | Information & communication | 2018 |
| Treval Engineering Limited | Manufacturing | 1999 |
| Tribe-People Limited | Administrative & support | 2009 |
| Trident Healthcare Solutions Limited | Administrative & support | 2021 |
| Trinity Education Dyslexia Assessment & Training Limited | Education | 2015 |
| Trinity GAS Plumbing Electrical Ltd | Construction | 2023 |
| Trinity Nest Properties Ltd | Hospitality | 2025 |
| Trinity Village (Phase 1B) Residents Company Limited | Households | 2011 |
| Trinity Village Estate Company Limited | Households | 2011 |
| Trio Consulting (UK) Limited | Professional & scientific | 1994 |
| Trio Investments Limited | Professional & scientific | 2011 |
| Triple a Educational Consult Ltd | Administrative & support | 2023 |
| Triple EYE Limited | Professional & scientific | 2024 |
| Triple Star Fire & Security Limited | Administrative & support | 2006 |
| Triumph Construction Ltd | Construction | 2017 |
| TRL Electrical Services Ltd | Construction | 2022 |
| Trosley Limited | Construction | 2010 |
| True Dawn Limited | Professional & scientific | 2018 |
| True North Consulting Group Ltd | Administrative & support | 2019 |
| True Seed Ltd | Wholesale & retail | 2021 |
| Trueight Ltd | Information & communication | 2026 |
| Truenorth Search Limited | Administrative & support | 2023 |
| Truest Health Limited | Information & communication | 2016 |
| Trussall ROW Limited | Information & communication | 2009 |
| Trustee Alarms Limited | Administrative & support | 2018 |
| Trustee Fabrications Limited | Manufacturing | 2020 |
| Trustee Fire and Security Limited | Administrative & support | 1978 |
| Truvend Group Ltd | Wholesale & retail | 2025 |
| TRW Consultants Limited | Administrative & support | 2017 |
| TS Accounting Services Ltd | Professional & scientific | 2015 |
| TS Design Studio Ltd | Manufacturing | 2018 |
| TS Detailing Limited | Wholesale & retail | 2025 |
| Tsalach Services Ltd | Health & social care | 2025 |
| Tsanga Consulting Ltd | Wholesale & retail | 2013 |
| Tshirt Showroom Ltd | Wholesale & retail | 2014 |
| Tsight IT Ltd | Information & communication | 2019 |
| Tsubaki London Limited | Real estate | 2021 |
| TSZ Construction Ltd | Construction | 2023 |
| TTC Leisure Group Limited | Administrative & support | 2016 |
| Ttny Properties Limited | Real estate | 2021 |
| Ttnywbm Ltd | Real estate | 2025 |
| Tudor Glass & Security Limited | Administrative & support | 2008 |
| Tuhi Investment Limited | Financial services | 2021 |
| Tuhi UK Limited | Health & social care | 2020 |
| Tula Balance Ltd | Other services | 2024 |
| Tully Electrical Ltd | Construction | 2021 |
| Turay and Co. Limited | Information & communication | 2003 |
| Turbowash Solutions Ltd | Administrative & support | 2026 |
| Turnkey GRP Ltd | Construction | 2019 |
| Turnpike Property Limited | Real estate | 2023 |
| Turpin of Greenwich Limited | Real estate | 2001 |
| Turtle Group Limited | Wholesale & retail | 2024 |
| Tushy's Fishy Ltd | Hospitality | 2024 |
| Tutoring Learning Base Ltd | Education | 2025 |
| TV Studio Group Limited | Administrative & support | 2018 |
| TVR Groundworks Ltd | Construction | 2018 |
| TWELVE01 Limited | Professional & scientific | 2018 |
| TWG the Works Group Ltd | Professional & scientific | 2026 |
| Twilight Trading Ltd | Wholesale & retail | 2026 |
| Twinz & Sister Limited | Hospitality | 2026 |
| Twixus (Holding) Limited | Financial services | 2022 |
| Two Little ES Ltd | Other services | 2015 |
| Two Oceans Properties Ltd | Real estate | 2012 |
| Two Potts Property Limited | Real estate | 2006 |
| Two TEN Consulting Ltd | Professional & scientific | 2019 |
| TY Town Limited | Wholesale & retail | 2023 |
| Tyagi Estates Limited | Real estate | 2019 |
| Tyler Services Ltd | Administrative & support | 2025 |
| Typoria Ltd | Information & communication | 2025 |
| Tyrolese (751) Limited | Professional & scientific | 2012 |
| U Turn Community Solutions Limited | Education | 2016 |
| U-Recruitment Ltd | Administrative & support | 2018 |
| U.R Esturi Ltd | Information & communication | 2015 |