| Trusted Payer Limited | Information & communication | 2025 |
| Trusted Touch Medical Aesthetics Ltd | Health & social care | 2022 |
| Trustguard Solutions Ltd | Information & communication | 2023 |
| Truth&Freedom Limited | Administrative & support | 2024 |
| Trutrak FR Ltd | Information & communication | 2020 |
| TRW Solutions Consultants Limited | Administrative & support | 2017 |
| TS Projects Ltd | Professional & scientific | 2023 |
| TSE Electrical Ltd | Construction | 2018 |
| TSG Barber Limited | Other services | 2020 |
| TSI Industrial Roofing Services Ltd | Construction | 2020 |
| TT Digital Limited | Information & communication | 2018 |
| TT Education Limited | Education | 2012 |
| TT Interiors Ltd | Information & communication | 2024 |
| Ttak Services Limited | Education | 2024 |
| TTC Refrigeration Ltd | Manufacturing | 2015 |
| Ttlc Properties Ltd | Real estate | 2021 |
| TU4 Prescriptions Limited | Wholesale & retail | 2018 |
| Tudor Farm Broxbourne LLP | | 2023 |
| Tudor Gardens (Framlingham) Management Company Limited | Households | 2017 |
| Tudor Travel Ltd | Administrative & support | 2024 |
| Tuffour Pharm Group Limited | Financial services | 2016 |
| Tufina Limited | Real estate | 2023 |
| Tufnell Way (Colchester) General Management Company Limited | Households | 2007 |
| Tugby Place (Chelmsford) Management Company Limited | Households | 1985 |
| Tukmar Holdings Ltd | Wholesale & retail | 2026 |
| Tuli Kids Limited | Wholesale & retail | 2019 |
| Tulsa Developments Ltd | Construction | 2023 |
| Tuna Ocean Ltd | Hospitality | 2025 |
| Turf in Essex Limited | Agriculture & fishing | 2017 |
| Turf in London Limited | Agriculture & fishing | 2020 |
| Turingenius Endowment London | Professional & scientific | 2025 |
| Turner Engineering & Project Management Ltd | Professional & scientific | 2025 |
| Turner Process Equipment Limited | Manufacturing | 2003 |
| Turners Reinforcements Limited | Manufacturing | 2012 |
| Turners Software Solutions Limited | Information & communication | 2013 |
| Turnkey Telecom Solutions Limited | Information & communication | 2001 |
| Turtle Farms Limited | Construction | 2013 |
| Turtle Quirk Ltd | Information & communication | 2020 |
| Tuscan Investments Limited | Real estate | 2013 |
| Tushiyah Care Ltd | Health & social care | 2016 |
| Tutanalytics Ltd | Information & communication | 2024 |
| Tutorgrad Ltd | Education | 2023 |
| Tutorkids Limited | Education | 2025 |
| Tvaste Ltd | Real estate | 2020 |
| TVR Building Services Limited | Construction | 2016 |
| TVR Instruments Limited | Wholesale & retail | 2011 |
| TWA Properties Ltd | Real estate | 2019 |
| Twana Fruit & VEG Ltd | Wholesale & retail | 2025 |
| TWB Carpentry & Joinery Ltd | Construction | 2020 |
| TWB Projects Ltd | Construction | 2024 |
| Twelect Ltd | Construction | 2024 |
| Twenty Nineteen MAM Ltd | Real estate | 2019 |
| Twenty Two Management Company Limited | Households | 2006 |
| TWH Tree Services Limited | Agriculture & fishing | 1996 |
| Twha Limited | Professional & scientific | 2003 |
| Twigg Contractors Limited | Construction | 2026 |
| Twin Welding & Fabrications Limited | Manufacturing | 2016 |
| Twin Welding Limited | Manufacturing | 2021 |
| Twinaire Limited | Administrative & support | 2017 |
| Twins Traders Ltd | Wholesale & retail | 2025 |
| Twisted Blonde Ltd | Other services | 2024 |
| Twizy Ltd | Professional & scientific | 2023 |
| Two Brews of Essex Ltd | Wholesale & retail | 2016 |
| Two Cubed Creative Ltd. | Professional & scientific | 2017 |
| Two Elle Ltd | Information & communication | 2013 |
| Two Hoots Property Ltd | Real estate | 2024 |
| Two Islands Group Limited | Wholesale & retail | 2023 |
| Two Roads Diverged | Professional & scientific | 2015 |
| Two Sugars Cafe Limited | Hospitality | 2010 |
| Two Tides Landscaping and Supplies Ltd | Wholesale & retail | 2026 |
| Twqa Limited | Information & communication | 2022 |
| Tyeboom Cleaning Services Ltd | Other services | 2024 |
| Tyler JNB Limited | Construction | 2024 |
| Tyler Property Services Limited | Real estate | 2023 |
| Tylt Consultancy Limited | Administrative & support | 2012 |
| Tymoho Limited | Real estate | 2023 |
| Tymperley Court Maintenance Company Limited | Households | 1992 |
| Tynan Social Work Limited | Health & social care | 2026 |
| Tynedale Square (Highwoods) Management Company Limited | Households | 1988 |
| Tysons Tools Ltd | Administrative & support | 2016 |
| TZE ONG Ltd | Arts & recreation | 2022 |
| U S Auto Services Ltd | Wholesale & retail | 2025 |
| U.K. Schools Limited | Extraterritorial | 1996 |
| Uaa-Mgmt Limited | Arts & recreation | 2024 |
| Uatrans Ltd | Transport & logistics | 2021 |
| Ubeequee Limited | Information & communication | 2019 |
| Ubernet Ltd | Administrative & support | 2017 |
| Ubernet Properties Limited | Real estate | 2018 |
| Uchemokoli Foundation Ltd | Health & social care | 2025 |
| Uclink Logistics Ltd | Transport & logistics | 2015 |
| Ucmf-It Ltd | Information & communication | 2011 |
| Ucmp Builders Ltd | Construction | 2025 |
| UCP (UK) Ltd | Administrative & support | 2011 |
| Ucsc Ltd | Arts & recreation | 2011 |
| Uesu Limited | Wholesale & retail | 2010 |
| Ugwuadutech Ltd | Information & communication | 2025 |
| UHY Corporate Finance Limited | Financial services | 2001 |
| UHY Financial Planning Limited | Administrative & support | 1997 |
| UHY Hacker Young LLP | | 2007 |
| UIS Holdings Limited | Financial services | 2015 |