| Trendifysale Ltd | Wholesale & retail | 2025 |
| Trendlox Ltd | Manufacturing | 2024 |
| Trendwave Traders Ltd | Wholesale & retail | 2025 |
| Trendy Barbers Romford Limited | Other services | 2024 |
| Trendy CUT Romford Limited | Real estate | 2023 |
| Trendytreazure Ltd | Wholesale & retail | 2025 |
| Trendyy Limited | Wholesale & retail | 2025 |
| Trescherries Limited | Professional & scientific | 2012 |
| TRI H Ltd | Construction | 2015 |
| Triag Consultancy Services Limited | Health & social care | 2022 |
| Triangle Associates Limited | Administrative & support | 2006 |
| Triangle Consulting Group Limited | Administrative & support | 1999 |
| Triangle Controls Limited | Construction | 2014 |
| Triangle Recruitment Limited | Administrative & support | 1995 |
| Tribe Cybersecurity Ltd | Information & communication | 2023 |
| Tribe Merchandising UK Limited | Wholesale & retail | 2018 |
| Tricon Foodservice Consultants Limited | Professional & scientific | 1980 |
| Tricon Group Ltd | Financial services | 2024 |
| Tricore Global Limited | Financial services | 2025 |
| Tried and Truth Care Ltd | Health & social care | 2024 |
| Triforcegroup Limited | Information & communication | 2025 |
| Trimhouse Limited | Wholesale & retail | 2025 |
| Trims Contractors Limited | Construction | 2019 |
| Trinity CS Consult Ltd | Wholesale & retail | 2025 |
| Trinity Rock Properties Limited | Real estate | 2025 |
| Trinket Trunk Limited | Wholesale & retail | 2021 |
| Triple a Homes Ltd | Real estate | 2023 |
| Triple BB Limited | Construction | 2019 |
| Triplezerosix Management Ltd | Professional & scientific | 2025 |
| TRIPPLE888 Caribbean Restaurant Ltd | Hospitality | 2025 |
| Tripplemss Ltd | Real estate | 2025 |
| Trishakthi Group Limited | Real estate | 2022 |
| Tritan Projects UK Ltd | Real estate | 2019 |
| Tritech Utilities Ltd | Construction | 2017 |
| Triton Traders Ltd | Wholesale & retail | 2015 |
| Triumph Global Limited | Real estate | 2007 |
| Triveni Dwellings Limited | Real estate | 2025 |
| Trivia Fiscals Ltd | Professional & scientific | 2022 |
| Trix Support Limited | Administrative & support | 2022 |
| Trkrz Studios Ltd | Information & communication | 2022 |
| Trojan Fire & Security Ltd | Administrative & support | 2019 |
| Tron Food Ltd | Wholesale & retail | 2026 |
| Tropila Enterprises Limited | Administrative & support | 2008 |
| Tros Y Waen Holidays Ltd | Hospitality | 2016 |
| Troy's Double Glazing Ltd | Construction | 2022 |
| TRS Alliance Limited | Real estate | 2020 |
| True Hearts Unite CIC | Health & social care | 2023 |
| True Skyn Clinic Ltd | Health & social care | 2021 |
| Trueseal Doors & Windows Ltd | Manufacturing | 2026 |
| Truly Scrumptious Day Care Nursery Limited | Education | 2009 |
| Truscope Limited | Information & communication | 2020 |
| Trust Doors Ltd | Transport & logistics | 2018 |
| Trust Point Homes Ltd | Real estate | 2025 |
| Trust Property Maintenance Ltd | Administrative & support | 2024 |
| Trustcert Energy & Safety Services Ltd | Professional & scientific | 2024 |
| Trusted Alliance Ltd | Transport & logistics | 2026 |
| Trusted GAS MAN Limited | Construction | 2017 |
| Trustedge Ltd | Real estate | 2023 |
| Trustguard Services Ltd | Administrative & support | 2024 |
| Trustkey Financial Ltd | Financial services | 2016 |
| Trustway Management Solutions Ltd | Construction | 2026 |
| Truth Academy CIC | Education | 2023 |
| TRX Network Ltd | Professional & scientific | 2026 |
| TRZ Design & Construction Ltd | Construction | 2026 |
| TS Biomed Ltd | Health & social care | 2026 |
| TS Business Consultants Ltd | Professional & scientific | 2014 |
| TS Civil Engineering Limited | Construction | 2015 |
| TS Joinery Solutions Limited | Wholesale & retail | 2015 |
| TS Nexus Limited | Construction | 2010 |
| TS Property Group London Ltd | Real estate | 2025 |
| TS18 Properties Ltd | Real estate | 2018 |
| Tsa-Powerscrub Ltd | Administrative & support | 2025 |
| TSB Biohazard Cleaning Limited | Administrative & support | 2024 |
| TSD FIX Ltd | Construction | 2019 |
| TSG Recruitment Ltd | Administrative & support | 2022 |
| TSL Logistics Limited | Transport & logistics | 2024 |
| TSS Management UK Ltd | Administrative & support | 2024 |
| Tssrct Technologies Limited | Financial services | 2024 |
| TST Foods Ltd | Wholesale & retail | 2009 |
| TST Support Service Limited | Health & social care | 2020 |
| Tsurai Romford Limited | Hospitality | 2025 |
| Tsvetanov Limited | Construction | 2010 |
| TSW Outlet Ltd | Wholesale & retail | 2025 |
| Ttllm Limited | Transport & logistics | 2021 |
| TUD Services Limited | Construction | 2023 |
| Tudar Properties Ltd | Real estate | 2018 |
| Tudar Skills Limited | Education | 2016 |
| Tudor Analytics Ltd | Professional & scientific | 2026 |
| Tudor House Law Limited | Professional & scientific | 2017 |
| Tukis UK Logistics Ltd | Transport & logistics | 2013 |
| Tulip Properties Portfolio Ltd | Real estate | 2023 |
| Tullamore Maintenance Limited | Construction | 2014 |
| Tumbridge Home Services Ltd | Other services | 2015 |
| Turko Ltd | Construction | 2018 |
| Turna Brothers Construction Ltd | Construction | 2021 |
| Turner Comms Ltd | Information & communication | 2022 |
| Turner Health Group Ltd | Public administration | 2024 |
| Turner Healthcare Ltd | Health & social care | 2026 |
| Turners Mill Developments Ltd | Real estate | 2023 |
| Turtl Energy Ltd | Construction | 2026 |