| Trusyncinfotech Limited | Information & communication | 2026 |
| Truth About LG Limited | Public administration | 2024 |
| Truth in Colour Ltd | Other services | 2025 |
| Truth Investments Ltd | Real estate | 2019 |
| Trylight Productions Ltd | Administrative & support | 2018 |
| TS Body Repairs Limited | Wholesale & retail | 2025 |
| TS Plus International Limited | Wholesale & retail | 2025 |
| TSC Plumbing Services Ltd | Construction | 2010 |
| TSG Holdings (UK) Limited | Financial services | 2015 |
| TSK Budgets Limited | Wholesale & retail | 2019 |
| TSK Solutions Ltd | Professional & scientific | 2012 |
| TSL Interiors Ltd | Professional & scientific | 2021 |
| TSN Accountancy Limited | Professional & scientific | 2022 |
| Tsog Limited | Construction | 2024 |
| TSS MOT Center Ltd | Wholesale & retail | 2025 |
| Tsume Supplies Ltd | Wholesale & retail | 2020 |
| Tsvai Solutions Limited | Wholesale & retail | 2025 |
| TSW Marketing Limited | Other services | 2010 |
| TSW Media Limited | Other services | 2012 |
| TT Construction (Northern) Limited | Construction | 1996 |
| TT Law Ltd | Professional & scientific | 2013 |
| TT2905 Limited | Wholesale & retail | 2025 |
| Ttcn Ltd | Hospitality | 2026 |
| TTE Design Ltd | Professional & scientific | 2024 |
| TTH NE Limited | Hospitality | 2023 |
| Ttjs Group Limited | Financial services | 2022 |
| TTM (NE) Ltd | Construction | 2026 |
| TTM Holdings (NE) Limited | Financial services | 2022 |
| TTM Management Limited | Professional & scientific | 2011 |
| TTP Bots Ltd | Information & communication | 2021 |
| TTS Offshore Limited | Administrative & support | 2019 |
| TTT Coffee Ltd | Manufacturing | 2022 |
| TTW International Ltd | Wholesale & retail | 2023 |
| TU Analytics Ltd | Professional & scientific | 2024 |
| Tuba Atas Ltd | Wholesale & retail | 2025 |
| Tubby Media Ltd | Manufacturing | 2021 |
| Tudor Newcastle Ltd | Construction | 2019 |
| Tughall Manor Management Company Limited | Real estate | 2004 |
| Tulip Property Limited | Real estate | 2017 |
| Tulips and Beetles Ltd | Manufacturing | 2026 |
| Tumbling Dice Limited | Professional & scientific | 2003 |
| Tumz Property Ltd | Real estate | 2024 |
| Tundas Capital Limited | Financial services | 2015 |
| Tuneator Limited | Information & communication | 2025 |
| TUP TUP Palace Limited | Hospitality | 2008 |
| Turbinesmax Ltd | Wholesale & retail | 2026 |
| Turbo Nation Limited | Wholesale & retail | 2025 |
| Turbulence Tamers Ltd | Manufacturing | 2015 |
| Turc Limited | Real estate | 2008 |
| Turilon Limited | Information & communication | 2024 |
| Turkington Psychiatry Limited | Health & social care | 2010 |
| Turkish Barber Hair Art Limited | Other services | 2016 |
| Turkish Cafe & Bar Ltd | Hospitality | 2024 |
| Turn NE Limited | Wholesale & retail | 2014 |
| Turnbull Coatings Ltd | Construction | 2018 |
| Turner Holdings (NE) Ltd | Real estate | 2020 |
| Turner Left Ltd | Administrative & support | 2024 |
| Turning Tides Psychology Ltd | Health & social care | 2023 |
| Turnitin UK Ltd | Administrative & support | 2010 |
| Turnkey Hmos Ltd | Real estate | 2026 |
| Turnleaf Later Lifestyles Limited | Hospitality | 2025 |
| Turnover XXV Ltd | Information & communication | 2025 |
| Turpentyne Ltd | Education | 2017 |
| Turretpharma Ltd | Wholesale & retail | 2025 |
| Turtle Childcare Ltd | Health & social care | 2020 |
| Turtle Tots North East Limited | Arts & recreation | 2018 |
| Turtle's Wraparound Care Ltd | Health & social care | 2025 |
| Turtléar Ltd | Administrative & support | 2023 |
| TUS Ltd | Administrative & support | 2019 |
| Tutto Products & Services Ltd | Wholesale & retail | 2025 |
| Tutum Group Holdings Limited | Financial services | 2023 |
| TVC Gloucester Limited | Wholesale & retail | 2023 |
| TVS Digital Services Limited | Information & communication | 2001 |
| Tvst Property Group Ltd | Real estate | 2026 |
| TVV Productions Limited | Information & communication | 2006 |
| TW Investments North East Ltd | Real estate | 2024 |
| Twam Enterprises Ltd | Wholesale & retail | 2017 |
| Tweasy Ltd | Information & communication | 2024 |
| Tweed Technology Limited | Information & communication | 2011 |
| Twelve Muqam Ltd | Wholesale & retail | 2023 |
| Twenty Eight Beauty Ltd | Other services | 2026 |
| Twenty Fourth Ltd | Professional & scientific | 2024 |
| Twenty Third Ltd | Health & social care | 2014 |
| Twenty Two Properties NE Ltd | Real estate | 2024 |
| Twentysix Productions Ltd | Wholesale & retail | 2021 |
| TWH Autoservices Ltd | Wholesale & retail | 2019 |
| TWH Property Solutions Ltd | Real estate | 2026 |
| Twilsalaso Limited | Wholesale & retail | 2021 |
| Twilspremium Limited | Wholesale & retail | 2021 |
| Twinfix Building and Joinery Ltd | Construction | 2017 |
| Twinkle Twinkle Little Star Limited | Real estate | 2025 |
| Twins 24 Studio Limited | Manufacturing | 2025 |
| Twinview Limited | Information & communication | 2019 |
| Twit Solution Limited | Information & communication | 2026 |
| Twizell Estates Limited | Agriculture & fishing | 2020 |
| Twizell Poultry (Ponteland) Limited | Agriculture & fishing | 1983 |
| Two Ball Lonnen American Market Limited | Wholesale & retail | 2025 |
| Two Ball Lonnen Euro Market Limited | Wholesale & retail | 2025 |
| Two Ball Lonnen Indian Restaurant Ltd | Hospitality | 2019 |
| Two Belle Grove Villas Limited | Extraterritorial | 2002 |