| Thinkhoos Ltd | Information & communication | 2025 |
| Thomas Black Developments Limited | Real estate | 2006 |
| Thorad Ltd | Real estate | 2021 |
| Thornex Developments Limited | Financial services | 2022 |
| Thornex Limited | Construction | 2014 |
| Thrive Collaborative Care Ltd | Professional & scientific | 2025 |
| Thrive Enterprises Ltd | Wholesale & retail | 2016 |
| THT Associates Limited | Construction | 2021 |
| Tilbury Property Limited | Real estate | 2003 |
| Tilford Estates Limited | Real estate | 2017 |
| Tilly Nails Spa Ltd | Other services | 2023 |
| Time Consultants Family Partnership LLP | | 2021 |
| Timec 1673 Limited | Real estate | 2018 |
| Tio-Ivy Holdings Limited | Real estate | 2024 |
| TIS (NGA) Limited | Professional & scientific | 2015 |
| TM8 Limited | Education | 2022 |
| TMD Brickwork Limited | Construction | 2018 |
| Tmfrt Property Ltd | Real estate | 2025 |
| TN Health Care North East Ltd | Professional & scientific | 2023 |
| TN Locum Ltd | Health & social care | 2022 |
| TN Precision Engineering Ltd | Professional & scientific | 2024 |
| Toby Mods Ltd | Information & communication | 2026 |
| Tokai Trading Ltd | Wholesale & retail | 2024 |
| TOM D Rigging Services Ltd | Construction | 2026 |
| TOM Ryan Family Partnership LLP | | 2020 |
| Tomax Homes Limited | Real estate | 2017 |
| Tomlinson, Hall Group Limited | Financial services | 2025 |
| Tomlinson,Hall & Company Limited | Manufacturing | 1954 |
| Top Drawer Properties Limited | Health & social care | 2004 |
| Top TAN & Beauty NO 1 Limited | Other services | 2018 |
| Topp Ltd | Real estate | 2021 |
| Topside Facade Engineering Limited | Manufacturing | 2000 |
| Touchdown Offices Limited | Information & communication | 2003 |
| Towngate Enterprises Limited | Wholesale & retail | 2008 |
| Townsley Consultancy Ltd | Professional & scientific | 2021 |
| TR Simmonds Developments Ltd | Construction | 2014 |
| TR Simmonds Investments Ltd | Real estate | 2014 |
| TR Simmonds Property LLP | | 2020 |
| Tracerco Global (Topco) Limited | Professional & scientific | 2022 |
| Tracerco Limited | Professional & scientific | 2002 |
| Traff Ltd | Administrative & support | 2026 |
| Treat Your Staff Ltd | Other services | 2023 |
| Treebin Limited | Information & communication | 2010 |
| Tribo - Synthetics Limited | Wholesale & retail | 2004 |
| Trinity Legends LLP | | 2019 |
| Triplex Lloyd Properties Limited | Construction | 1887 |
| Trium Consultancy Group Limited | Professional & scientific | 2026 |
| True Colours Rising Limited | Wholesale & retail | 2025 |
| True North Performance Improvement Ltd | Professional & scientific | 2018 |
| TS1 Property Maintenance Services Ltd | Households | 2025 |
| TSD Facades Limited | Construction | 2015 |
| Tths North East Ltd | Manufacturing | 2019 |
| Tulus Properties Limited | Real estate | 2018 |
| Tulus Properties Partnership LLP | | 2019 |
| Turbo Tool Hire Limited | Wholesale & retail | 2021 |
| Turboactive Limited | Wholesale & retail | 1997 |
| Turtle North East Limited | Real estate | 2017 |
| TW Civils Ltd | Construction | 2026 |
| TW Teesside Ltd | Professional & scientific | 2020 |
| Twenty Twenty Financial Solutions Limited | Financial services | 2017 |
| Twin Line Access Ltd | Construction | 2026 |
| Twinkle Coffin 3D Ltd | Wholesale & retail | 2026 |
| TYA (London) Limited | Administrative & support | 2016 |
| Tyler Allen RA Limited | Construction | 2024 |
| U Bhatti and F Zaman W P Ltd | Administrative & support | 2024 |
| UA Select Ltd | Wholesale & retail | 2024 |
| UK AI Group Ltd | Information & communication | 2023 |
| UK Construct Limited | Construction | 2000 |
| UK De-Fleet Services Limited | Manufacturing | 2004 |
| UK Energy Support Limited | Professional & scientific | 2020 |
| UK Rail Ltd | Transport & logistics | 2013 |
| UK Travel Luxury Ltd | Wholesale & retail | 2026 |
| Uner Ltd | Transport & logistics | 2024 |
| Union Gilkinson Ltd | Financial services | 2020 |
| Unique Professional Properties Limited | Real estate | 2016 |
| Unishoplive Ltd | Wholesale & retail | 2021 |
| United Merchants Ltd | Information & communication | 2020 |
| UNO Pizzeria 4U Ltd | Hospitality | 2021 |
| Upstream Asset Services Limited | Real estate | 2012 |
| Urban Quarters Partnership LLP | | 2020 |
| Urbanconcepts Property Services Ltd | Real estate | 2024 |
| URO3 Healthcare Limited | Manufacturing | 2024 |
| Urocare 4 U Ltd | Health & social care | 2026 |
| Used Food Machines Ltd | Manufacturing | 2016 |
| Used Food Machines Worldwide Ltd | Manufacturing | 2018 |
| Usman Healthcare Limited | Health & social care | 2023 |
| Utility Civil Engineering Limited | Construction | 2017 |
| UWE Houses LLP | | 2017 |
| Valles Collins Estates LLP | | 2023 |
| Valles Collins Holdings Ltd | Real estate | 2023 |
| Vanguard Energy Projects Ltd | Professional & scientific | 2018 |
| Vanilla Black Chancery Limited | Hospitality | 2014 |
| Vanilla Rocca Properties Limited | Real estate | 2025 |
| Vara.Xr Limited | Information & communication | 2021 |
| Vase Group Limited | Financial services | 2025 |
| Vase Homes Limited | Real estate | 2025 |
| Veliath Enterprise PVT Limited | Hospitality | 2023 |
| Velkie Consultants Limited | Information & communication | 2011 |
| Veni Govender Family Ltd | Real estate | 2021 |
| Veni Govender Family Partnership LLP | | 2021 |