| Trelonk Biosciences Limited | Professional & scientific | 2019 |
| Treloyhan Manor (South) Limited | Households | 2019 |
| Treluggan Court Management Company Limited | Households | 1999 |
| Treluggan Farms Ltd | Professional & scientific | 1984 |
| Trelyn Developments Limited | Construction | 2020 |
| Trelys Ltd | Financial services | 2025 |
| Tremarnic Ltd | Administrative & support | 2017 |
| Trembo Medical Limited | Health & social care | 2019 |
| Tremewan Removals & Storage Ltd | Transport & logistics | 2022 |
| Tremletts Limited | Wholesale & retail | 2014 |
| Tremorvah Construction Ltd | Construction | 2025 |
| Tremorvah Residents Association Limited | Households | 1985 |
| Trenarren House Carlyon Bay Management Limited | Households | 2021 |
| Trenerry Woods Limited | Real estate | 2024 |
| Trengrouse Farm Ltd | Financial services | 2018 |
| Trenona Limited | Manufacturing | 2011 |
| Trenowth Estate Management Ltd | Households | 2007 |
| Tresco Holdings (Adam) LLP | | 2018 |
| Tresco Island Limited | Hospitality | 2021 |
| Treskerby Management Company (Redruth) Limited | Households | 2018 |
| Tresyjo LLP | | 2024 |
| Trethella NO. 1 | Professional & scientific | 2015 |
| Trethellan Estates 1 Limited | Construction | 2020 |
| Trethellan Estates 2 Limited | Construction | 2022 |
| Trethellan Estates 3 Limited | Construction | 2024 |
| Trethellan Estates 4 Limited | Real estate | 2026 |
| Trethellan Holdings Limited | Professional & scientific | 2020 |
| Trethewy Enterprises Ltd | Professional & scientific | 2016 |
| Trevails of Truro Limited | Wholesale & retail | 1976 |
| Trevarno Home Farm Barns Management Limited | Households | 2013 |
| Trevean (Cornwall) Ltd | Financial services | 2020 |
| Trevear Farms Limited | Agriculture & fishing | 2010 |
| Treveglos Farm Limited | Agriculture & fishing | 2010 |
| Trevena Trading Ltd | Arts & recreation | 1999 |
| Trevenson Court Management Company Limited | Households | 1984 |
| Treverran Homes Limited | Construction | 2010 |
| Treverran Investments Limited | Real estate | 2015 |
| Treveth Commercial LLP | | 2021 |
| Treveth Development LLP | | 2019 |
| Treveth Holdings LLP | | 2019 |
| Treveth Investment LLP | | 2021 |
| Treveth Pydar LLP | | 2023 |
| Treveth Tranche a LLP | | 2019 |
| Trevissome Park Limited | Construction | 2015 |
| Trevithick Press Ltd | Information & communication | 2018 |
| Trevone Fields Limited | Households | 2017 |
| Trevow Heights Management Company Limited | Households | 2025 |
| Trewartha Chapel Farm Limited | Agriculture & fishing | 2010 |
| Trewartha Court Management Company Limited | Real estate | 1999 |
| Trewennack Management Co Ltd | Households | 2023 |
| Trewidden Management Limited | Real estate | 1984 |
| Trewince Ltd | Hospitality | 2012 |
| Trewince Manor Holdings Ltd | Hospitality | 2024 |
| Trewithen Energy Limited | Other services | 2014 |
| Trewithen Estate Limited | Agriculture & fishing | 1976 |
| Trewithen Estate Management Company Limited | Construction | 1964 |
| Trewithen Gardens and Parks LLP | | 2017 |
| Trial Balance Consulting Holdings Ltd | Real estate | 2025 |
| Trial Balance Consulting Limited | Real estate | 2009 |
| Trice Leisure Ltd | Wholesale & retail | 2015 |
| Trident Talent Ltd | Administrative & support | 2025 |
| Trigys Construction Ltd | Construction | 2021 |
| Trigys Ltd | Real estate | 2019 |
| Trillow Properties Ltd | Real estate | 2025 |
| Trink Dairy Limited | Agriculture & fishing | 2010 |
| Triplet Car Spares Limited | Professional & scientific | 1995 |
| Tripp Trading Limited | Real estate | 2025 |
| Tritonvogue Limited | Real estate | 1984 |
| Triveru Limited | Health & social care | 2014 |
| TRL Homes Limited | Extraterritorial | 2020 |
| Trophy Textiles SW Limited | Manufacturing | 2020 |
| Tropical Pressure Ltd. | Arts & recreation | 2014 |
| Trst Stock Ltd | Wholesale & retail | 2022 |
| True Teylu Childcare Ltd | Health & social care | 2022 |
| Trueclean Services Limited | Administrative & support | 2025 |
| Trueplayers Ltd | Information & communication | 2021 |
| Truro & Penwith Academy Trust | Education | 2014 |
| Truro & Penwith College Trust Limited | Professional & scientific | 2010 |
| Truro Aggregate Supplies Ltd | Transport & logistics | 2020 |
| Truro Amateur Operatic and Dramatic Society Ltd | Arts & recreation | 2009 |
| Truro and District Motor Club Limited | Arts & recreation | 1977 |
| Truro Building Services (Cornwall) Limited | Construction | 2009 |
| Truro Business Hub Events Ltd | Arts & recreation | 2018 |
| Truro Business Hub Limited | Real estate | 2015 |
| Truro Capital Limited | Hospitality | 2025 |
| Truro Cathedral Limited | Wholesale & retail | 2003 |
| Truro Cathedral School Limited | Education | 1960 |
| Truro Chiropractic Clinic Ltd | Health & social care | 2020 |
| Truro City Football in the Community | Education | 2026 |
| Truro Dental Care Limited | Health & social care | 2009 |
| Truro Development Company Ltd | Construction | 2019 |
| Truro Diocesan Board of Finance Limited(The) | Education | 1896 |
| Truro Dog Minding Ltd | Other services | 2023 |
| Truro EYE Care Limited | Health & social care | 2012 |
| Truro Fabrics Limited | Wholesale & retail | 2012 |
| Truro Fish and Chips Limited | Hospitality | 2018 |
| Truro Golf Club,Limited | Real estate | 1937 |
| Truro Gymnastics Club CIC | Arts & recreation | 2022 |
| Truro Harbourside Ltd | Construction | 2016 |
| Truro Heating & Plumbing Services Limited | Construction | 2002 |