| Trevor Winston Worth Limited | Professional & scientific | 2026 |
| Trevornick Farmhouse Lettings Limited | Real estate | 2024 |
| Trevornick Holiday Park Limited | Arts & recreation | 2010 |
| Trewin Bookkeeping Services Ltd | Professional & scientific | 2020 |
| TRI Ocean Products Limited | Wholesale & retail | 2006 |
| Tribal Songs Community Interest Company | Wholesale & retail | 2024 |
| Tribalmarx Ltd | Wholesale & retail | 2024 |
| Tribeology Limited | Wholesale & retail | 2017 |
| Trident Offshore Ltd | Construction | 2026 |
| Trilogy Property Services Ltd | Real estate | 2023 |
| Trim Design Limited | Professional & scientific | 2012 |
| Trinity Place Management (Plymouth) Limited | Real estate | 2004 |
| Trio Innovations Limited | Wholesale & retail | 2019 |
| Trio Technical Solutions Ltd | Information & communication | 2019 |
| Triple Crown Ventures Ltd | Hospitality | 2026 |
| Triple Junction Limited | Professional & scientific | 2008 |
| Tripleadebos Property Limited | Real estate | 2019 |
| Triscott Technical Solutions Ltd | Information & communication | 2018 |
| Trish Luxe Beauty Ltd | Other services | 2025 |
| Triskele Consulting Services Ltd | Professional & scientific | 2021 |
| Triumph Motorcycles (1984) Limited | Professional & scientific | 1984 |
| Trojan Motor Company Ltd | Wholesale & retail | 2023 |
| Troll Trader Limited | Wholesale & retail | 2010 |
| Tropic Breeze Limited | Administrative & support | 2001 |
| Tropical Feast Ltd | Manufacturing | 2025 |
| Tropical Glow Studio Ltd | Other services | 2025 |
| Trotters Riding Wear Limited | Wholesale & retail | 2013 |
| TRU Resells Limited | Wholesale & retail | 2025 |
| Tru-Tec Heating Ltd | Construction | 2019 |
| True Craft Carpentry Ltd | Construction | 2025 |
| True Financial Partnerships Limited | Financial services | 2016 |
| True Gritt Ltd | Hospitality | 2025 |
| True Wealth Management Limited | Financial services | 2011 |
| True Wealth Planning Solutions Limited | Financial services | 2016 |
| Trueform Leisure Solutions Ltd | Professional & scientific | 2025 |
| Truelop Limited | Real estate | 1988 |
| Truelove Management Limited | Real estate | 2005 |
| Truly Inspirational South West Ltd | Manufacturing | 2024 |
| Trundlewood Limited | Real estate | 2006 |
| Trurich Ventures Ltd | Construction | 2023 |
| Truro Garages Limited | Extraterritorial | 1968 |
| Truro Lock & Leave Limited | Transport & logistics | 2015 |
| Trust Paraplanning Ltd | Administrative & support | 2008 |
| Trusted Building Supplies Ltd | Wholesale & retail | 2024 |
| Trusted Financial Advice Group Ltd | Financial services | 2024 |
| Trustfood Consultants Limited | Other services | 2026 |
| TRY US First Ltd | Wholesale & retail | 2008 |
| TS Partners (Plymouth) Limited | Financial services | 2022 |
| TSL Scaffolding South West Ltd | Construction | 2025 |
| Tslh Property Ltd | Real estate | 2017 |
| TSM Healthcare Limited | Health & social care | 2022 |
| TSS Retail Ltd | Wholesale & retail | 2026 |
| Tszcomposite Ltd | Manufacturing | 2023 |
| TT & E Ltd | Real estate | 2026 |
| TT Combat Retail Ltd | Wholesale & retail | 2026 |
| TT Utilities South West Ltd | Construction | 2025 |
| TTH Holdings Limited | Financial services | 2020 |
| TTJ Developments Ltd | Real estate | 2024 |
| Ttshili Limited | Health & social care | 2017 |
| Tucker's Brook Management Company Limited | Households | 2005 |
| Tudor House Designs Limited | Wholesale & retail | 1995 |
| Tudor Price Properties Limited | Real estate | 2020 |
| Tudor Rose Tearooms and Garden Ltd | Hospitality | 2018 |
| Tufcoat Limited | Construction | 2004 |
| Tuffin & Co. Property Management Limited | Real estate | 2008 |
| Tugboats & Dolphins CIC | Arts & recreation | 2024 |
| Tuku Days Limited | Transport & logistics | 2024 |
| Tuler Ltd | Manufacturing | 2018 |
| Tulgey Woods Sanctuary CIC | Arts & recreation | 2020 |
| Tulkaan Limited | Hospitality | 2018 |
| Tulken Developments (SW) Ltd | Real estate | 2019 |
| Tumbleweed Games Ltd | Information & communication | 2019 |
| Tunabuna Rail Limited | Construction | 2015 |
| Turkish Barber Ziravan Mahdi Ltd | Other services | 2022 |
| Turkish Barbers Plymouth Limited | Other services | 2024 |
| Turkish Style Barber Plymouth Ltd | Other services | 2023 |
| Turn the Page Therapy Limited | Health & social care | 2025 |
| Turner & Horswill Ltd | Construction | 2023 |
| Turner-Carlisle Enterprises Ltd | Administrative & support | 2022 |
| Turnover Consulting Ltd | Administrative & support | 2014 |
| Turnquay Wharf Ltd | Real estate | 2024 |
| Turnuppcrew Ltd | Construction | 2019 |
| Turton Retail Systems Limited | Wholesale & retail | 2000 |
| Tutor Know Ltd | Information & communication | 2026 |
| Tuwcroze Books Ltd | Information & communication | 2013 |
| TW Lady Decorators Ltd | Construction | 2018 |
| Twenty 02 Barbican Management Limited | Real estate | 2002 |
| Twenty Two 22 Group Limited | Hospitality | 2026 |
| Twice TOO Travel Limited | Administrative & support | 2024 |
| Twinavon Developments Limited | Construction | 1987 |
| Twins Construct Services Ltd | Manufacturing | 2026 |
| Twist Cafe Ltd | Wholesale & retail | 2018 |
| Twists Bistro Ltd | Hospitality | 2026 |
| Two Counties Motor Company Limited | Other services | 2012 |
| Two Mile Hill Court Management 1992 Limited | Households | 1991 |
| Two MRX Limited | Wholesale & retail | 2019 |
| Two Superior Studios Limited | Information & communication | 2013 |
| Twobro Properties Ltd | Real estate | 2019 |
| Twofour Broadcast Limited | Information & communication | 1989 |
| Twofour Group Limited | Information & communication | 2005 |