| Teepee Property Group Limited | Real estate | 2025 |
| Tees & Stripes Ltd | Wholesale & retail | 2026 |
| Tees Community Sports CIC | Administrative & support | 2022 |
| Tees Connect Ltd | Other services | 2024 |
| Tees Engineering Solutions (TES) Limited | Professional & scientific | 2022 |
| Tees Hips & Knees Limited | Health & social care | 2009 |
| Tees Valley Anaesthesia Limited | Health & social care | 2013 |
| Tees Valley Digestive Health Limited | Health & social care | 2018 |
| Tees View Developments Ltd | Real estate | 2017 |
| Teesside Aesthetics Ltd | Professional & scientific | 2018 |
| Teesside Financial Management Limited | Financial services | 1996 |
| Teesside Learning Academy Ltd | Education | 2025 |
| Teesside Maintenance Ltd. | Administrative & support | 2007 |
| Teesside Tesla Limited | Administrative & support | 2018 |
| Terra Nova Consultants Limited | Professional & scientific | 2021 |
| Tesla Teesside Limited | Administrative & support | 2018 |
| TF Boutique Ltd | Wholesale & retail | 2022 |
| TF Sound & Light Limited | Arts & recreation | 2012 |
| THE Bagel Brothers UK Limited | Hospitality | 2023 |
| THE Bakersmill Company Limited | Wholesale & retail | 2018 |
| THE Bearded Arborist Ltd | Agriculture & fishing | 2019 |
| THE Beauty Club NE Ltd | Other services | 2021 |
| THE Cabbage Patch Limited | Wholesale & retail | 2017 |
| THE Doocey Partnership LLP | | 2024 |
| THE Falcon at Hilton Limited | Hospitality | 2018 |
| THE Falcon Inn and Restaurant Limited | Hospitality | 2024 |
| THE Garden Goalie Company Limited | Extraterritorial | 2024 |
| THE Hanmade Gift Company Ltd | Manufacturing | 2024 |
| THE Heroes Journey - Education Ltd | Professional & scientific | 2026 |
| THE Maestro Online Ltd | Education | 2023 |
| THE Mockingbird Deli LP | | 2012 |
| THE Muse Party Company Ltd | Hospitality | 2014 |
| THE Old Rectory Management Company Yarm Limited | Real estate | 2007 |
| THE Outdoor Psychologist Ltd | Health & social care | 2022 |
| THE Striped Bear Ltd | Wholesale & retail | 2025 |
| THE Tack Room at Kirklevington Ltd | Hospitality | 2024 |
| THE Tack Room Deli Ltd | Wholesale & retail | 2025 |
| THE Triumph 2000 Register Limited | Other services | 2001 |
| THE Wilkinson Partnership Ltd | Hospitality | 2020 |
| Themis Psychology Limited | Health & social care | 2025 |
| Thirteen Environmental Services Ltd | Water & waste | 2018 |
| Thismustbtheplace Ltd | Extraterritorial | 2019 |
| Three Lights Limited | Professional & scientific | 2012 |
| Three Rivers Cafe Bar Ltd | Hospitality | 2018 |
| TLC Hospitality Ltd | Hospitality | 2026 |
| TMG Finance Ltd | Professional & scientific | 2012 |
| Together in Hospitality Ltd | Professional & scientific | 2018 |
| TOM Riley Limited | Health & social care | 2016 |
| TOP2TOE Academy Ltd | Other services | 2026 |
| Toptec Industries Ltd | Wholesale & retail | 2016 |
| Toptotoe Beauty and Skincare Ltd | Other services | 2023 |
| Total Bolt Solutions Limited | Administrative & support | 2012 |
| Total Recovery Under Strength of Truth Limited | Health & social care | 2022 |
| Total Wheel Solutions Limited | Wholesale & retail | 2016 |
| Town Centre Cars Limited | Extraterritorial | 2006 |
| Transcend Live Ltd | Information & communication | 2020 |
| Travel Lifestyle and Leisure Limited | Information & communication | 2024 |
| Triadsclothing Limited | Wholesale & retail | 2023 |
| Trustulo Limited | Wholesale & retail | 2024 |
| TS Power Ltd | Professional & scientific | 2023 |
| TS15 Engineering Ltd | Construction | 2025 |
| TS5 Limited | Professional & scientific | 2013 |
| Tutelina Solutions Limited | Professional & scientific | 2013 |
| Tyneside Preparation Cluster Limited | Manufacturing | 2000 |
| UNO Ristorante Yarm Ltd | Hospitality | 2016 |
| Urban Rose Yarm Ltd | Other services | 2026 |
| Valley Holdings (UK) Limited | Information & communication | 2011 |
| Vallily Rigging & Lifting Ltd | Construction | 2020 |
| Vani T Limited | Real estate | 2010 |
| VCF Endoscopy Services Ltd | Health & social care | 2021 |
| Victorious Motors Ltd | Wholesale & retail | 2025 |
| VJH Joinery Limited | Construction | 2021 |
| Vordex Limited | Professional & scientific | 2007 |
| VOY LUX Limited | Extraterritorial | 2025 |
| VRW Associates Limited | Health & social care | 2019 |
| W H Plant Services Ltd | Wholesale & retail | 2019 |
| W.O. Alderson Limited | Agriculture & fishing | 1963 |
| Walton Sharp Consultancy Ltd | Professional & scientific | 2023 |
| Warren Cleans Ltd | Administrative & support | 2025 |
| Watercare Management Services Ltd | Water & waste | 2013 |
| Wear Piccola Ltd | Wholesale & retail | 2023 |
| Wearslikethis Limited | Wholesale & retail | 2025 |
| Wellbeing North East Limited | Health & social care | 2025 |
| Whorlton Land Surveys Ltd | Construction | 2018 |
| Wild Elan Ltd | Wholesale & retail | 2025 |
| Wilkinson Legacies Ltd | Real estate | 2026 |
| Will IM Construction Services Ltd | Information & communication | 2024 |
| William Sharp Ltd | Wholesale & retail | 2010 |
| Willow Home Care Solutions Ltd | Health & social care | 2026 |
| Wilson Event Hire Ltd | Hospitality | 2024 |
| Wilton Recovery Ltd | Water & waste | 2019 |
| WLG Housing Limited | Real estate | 2020 |
| Wood Harrison Ltd. | Wholesale & retail | 2010 |
| Wood Home & Lettings Ltd | Real estate | 2025 |
| Woodhorn Homes Ltd | Construction | 2025 |
| Worsall Manor Investments Limited | Real estate | 2015 |
| Wrenn Soliza Solutions Ltd | Administrative & support | 2023 |
| WT Access Ltd | Construction | 2025 |
| Wyke Lodges Ltd | Construction | 2019 |
| Wyke Lodges NO 2 Ltd | Construction | 2021 |