| Tiny Blue Alien Limited | Professional & scientific | 2007 |
| TL Fleetcare Repair Ltd | Wholesale & retail | 2024 |
| TM Property Group Ltd | Financial services | 2025 |
| TMC Roofing Limited | Construction | 2024 |
| Tmoore Civil Engineering Limited | Extraterritorial | 2021 |
| TMP Commercial Ltd | Real estate | 2025 |
| TMP Land Consultants Ltd | Construction | 2024 |
| Toast Newquay Limited | Hospitality | 2026 |
| Toby Mackay Consults Ltd | Professional & scientific | 2025 |
| Toch Newquay Ltd | Wholesale & retail | 2021 |
| Toddletown Nursery and Daycare (Eastleigh) Ltd | Health & social care | 2018 |
| Toddletown Nursery and Daycare (Farnham) Ltd | Health & social care | 2021 |
| Todka Limited | Manufacturing | 2005 |
| Tokynva Ltd | Arts & recreation | 2021 |
| Tolcarne Properties Ltd | Construction | 2025 |
| TOM Thumb Newquay Ltd | Hospitality | 2016 |
| TOO Tipsy Limited | Professional & scientific | 2015 |
| Tooley Property Solutions Ltd | Construction | 2026 |
| Topmarcs Kitchen and Bathrooms Ltd | Construction | 2020 |
| TOR Creative CIC | Hospitality | 2025 |
| TOR Pottery Works LP | | 2024 |
| Torimbia Limited | Information & communication | 2012 |
| Total Office Print Services Limited | Real estate | 1995 |
| Totnes Computers Limited | Information & communication | 2007 |
| Totspresso Ltd | Wholesale & retail | 2023 |
| Towan IFA Limited | Financial services | 2019 |
| Towan Insurance Brokers Limited | Financial services | 2008 |
| Towan Property Services Ltd | Construction | 2025 |
| Towan Valley Management Company Limited | Hospitality | 2011 |
| Towan Wall Consulting Ltd | Professional & scientific | 2025 |
| Towan Wall Ltd | Real estate | 2022 |
| Tower Road Investments Ltd | Real estate | 2025 |
| Tower Road Laundrette Ltd | Administrative & support | 2017 |
| TPS (22) Limited | Hospitality | 2026 |
| TR7 Skatepark Ltd | Education | 2020 |
| TR8DE Co Ltd | Wholesale & retail | 2024 |
| Tradelance Limited | Administrative & support | 2026 |
| Training in Action Limited | Professional & scientific | 1990 |
| Trans Surf Limited | Wholesale & retail | 2012 |
| Travel Cornwall Ltd. | Wholesale & retail | 2000 |
| Travel Dreamers Ltd | Administrative & support | 2023 |
| Travellers Rest Trevarrian Ltd | Hospitality | 2025 |
| TRE Beau Secure Dog Fields Ltd | Arts & recreation | 2025 |
| Treasure Island Productions UK Ltd | Information & communication | 2022 |
| Treasure Square Ltd | Wholesale & retail | 2025 |
| Tredinnick Farm Accomodation Limited | Real estate | 2024 |
| Treehouse Newquay CIC | Hospitality | 2018 |
| Treescape Cornwall Limited | Agriculture & fishing | 2025 |
| Trefusis Flats Management Company Limited | Hospitality | 2012 |
| Tregarian Developments Ltd | Construction | 2006 |
| Tregonning Village Ltd | Construction | 2021 |
| Tregoss Livery Services Ltd | Agriculture & fishing | 2024 |
| Tregoyne Park Management Company Limited | Real estate | 2000 |
| Treheath Meadows (Carnon Downs) Management Company Limited | Households | 2021 |
| Trelawny Taverns Limited | Hospitality | 2018 |
| Treloy Touring Park Limited | Hospitality | 2008 |
| Trenance Cottages Newquay | Wholesale & retail | 2009 |
| Trenance Court RTM Company Limited | Households | 2018 |
| Trenance Road Flats Management Company Limited | Real estate | 2016 |
| Trenance Roads Limited | Transport & logistics | 2023 |
| Trendeal Energy Limited | Energy | 2013 |
| Tresellick Gardens Management Company Limited | Households | 2015 |
| Treseren Ltd | Professional & scientific | 2019 |
| Treskyber Yard Management Company Limited | Households | 2024 |
| Trethek Studio Ltd | Professional & scientific | 2022 |
| Trethiggey Caravan Park Limited | Real estate | 2018 |
| Trevalsa Hotel Limited | Real estate | 2002 |
| Trevalsa Management Company Limited | Households | 2003 |
| Trevanson Mews Management Limited | Households | 2016 |
| Trevarrian Court Apartments Management Company Ltd | Households | 2024 |
| Treveglos Court Limited | Real estate | 1988 |
| Treveglos Management Company Limited | Households | 2022 |
| Trevelga Court Management Company Limited | Households | 1987 |
| Trevemper 157 Limited | Households | 2023 |
| Trevemper Holdings Limited | Financial services | 2019 |
| Trevenna Property Ltd | Real estate | 2025 |
| Treverrick Consulting Ltd | Information & communication | 2025 |
| Trevilley Close (Management Company) Limited | Households | 2019 |
| Trevine Integrated Services Ltd | Wholesale & retail | 2025 |
| Trevithick Way Management Company Limited | Households | 2023 |
| Trevow Place Management Company Limited | Households | 2021 |
| Trewhiddle Court Property Management Company Ltd | Households | 2021 |
| Trewin Place Management Company Limited | Real estate | 2007 |
| Treworgans Holiday Park Ltd | Hospitality | 2017 |
| Trewyn James Fs&Q Consultancy Ltd | Professional & scientific | 2025 |
| Trivane Ltd | Professional & scientific | 2019 |
| True Cornish Deli Ltd | Hospitality | 2022 |
| True North Labratories Ltd | Wholesale & retail | 2026 |
| Truro Cafe 2024 Ltd | Hospitality | 2024 |
| Trusted Therapy Ltd | Health & social care | 2020 |
| Tryhornek (Management Company) Ltd. | Households | 2002 |
| TT Bars Ltd | Hospitality | 2024 |
| TT Buildings Ltd | Administrative & support | 2024 |
| Tucker Properties Limited | Real estate | 2011 |
| Two Bricks Design Company Ltd | Information & communication | 2024 |
| Tyler Investment Group Ltd | Financial services | 2025 |
| TZT Properties Ltd | Real estate | 2019 |
| U-Tow Caravans (Barrhill Holiday Park) Limited | Hospitality | 2004 |
| U-Tow Caravans Limited | Wholesale & retail | 1976 |
| U-Tow Holdings Limited | Professional & scientific | 1978 |