| Tegni Cymru CYF | Energy | 2008 |
| Termoil UK Ltd | Professional & scientific | 2014 |
| Texero Ltd | Administrative & support | 2019 |
| THE 41 Abbey Road Management Company Limited | Households | 2006 |
| THE Alex Llandudno Limited | Hospitality | 2018 |
| THE Bay Laser and Beauty Clinic Limited | Other services | 2015 |
| THE Baycourt Llandudno Ltd | Hospitality | 2026 |
| THE Biggest Twitch Limited | Arts & recreation | 2010 |
| THE Black & White Hospitality Group Ltd | Hospitality | 2025 |
| THE C V Lodge Ltd | Hospitality | 2025 |
| THE Creamery Business Parc Management Company Limited | Real estate | 2010 |
| THE DIY School Training Limited | Construction | 2018 |
| THE Doghouse Holyhead Limited | Other services | 2016 |
| THE Edit Partnership Ltd | Information & communication | 2021 |
| THE Escalator Media Limited | Administrative & support | 2025 |
| THE Garage Club Limited | Wholesale & retail | 2025 |
| THE Great Orme Exploration Society Limited | Arts & recreation | 1999 |
| THE HAM Bone (Llandudno) Limited | Hospitality | 2014 |
| THE Hidden Chapel Limited | Hospitality | 2021 |
| THE Kitchen Range (Llandudno) Limited | Wholesale & retail | 2013 |
| THE L Barbershop Llandudno Ltd | Other services | 2025 |
| THE Lemon Tree Tea Rooms Ltd | Hospitality | 2017 |
| THE Llandudno Ice Cream Company Ltd | Extraterritorial | 2014 |
| THE Magic Bar Live Limited | Hospitality | 2023 |
| THE Mediterranean Restaurant Llandudno Ltd | Hospitality | 2022 |
| THE New Kitchen Range Ltd | Wholesale & retail | 2025 |
| THE Northwich Drydock Company Limited | Transport & logistics | 2016 |
| THE Office Providers (Tops) Limited | Extraterritorial | 2018 |
| THE Pier Hotel Limited | Hospitality | 2006 |
| THE Playfulness LAB CIC | Professional & scientific | 2025 |
| THE Seaclyffe Hotel Limited | Hospitality | 2015 |
| THE Seaforth Agency Ltd | Wholesale & retail | 2021 |
| THE Seahorse Restaurant and Bistro Ltd | Hospitality | 2024 |
| THE Stella Llandudno Limited | Hospitality | 2023 |
| THE Willcocks Nursery School Limited | Education | 2005 |
| THE Wine Portfolio UK Limited | Wholesale & retail | 2009 |
| Theodore House Management Company Limited | Real estate | 2001 |
| Thomas & Jones (Surveyors) Limited | Professional & scientific | 2003 |
| Thomas Jones Lettings Ltd | Real estate | 2019 |
| Thomasmaintain Ltd | Construction | 2021 |
| Threadabead Holdings Limited | Real estate | 2022 |
| Threadabead Limited | Wholesale & retail | 2012 |
| Thrive Weight Management Limited | Health & social care | 2026 |
| Tidswell Property Lettings Ltd | Real estate | 2021 |
| Tiffany NW Limited | Hospitality | 2006 |
| TIR a Choed Ltd | Administrative & support | 2016 |
| TJH Builders Limited | Construction | 2016 |
| TK Nails Spa & Beauty Limited | Other services | 2025 |
| TL Offshore Services Ltd | Construction | 2024 |
| TLC Property Lettings and Sales Ltd | Real estate | 2025 |
| TM & a Holdings Ltd | Real estate | 2017 |
| TM Joinery Services Ltd | Construction | 2018 |
| Tolaz Barber Ltd | Other services | 2025 |
| Tolupampy Ventures Ltd | Health & social care | 2025 |
| Toned Within Limited | Health & social care | 2006 |
| Tonjaelectronics Limited | Manufacturing | 2020 |
| Toots Towers Ltd | Real estate | 2015 |
| Topline Digital Satellite Limited | Information & communication | 2002 |
| Total Perfection Auto Detailing Limited | Administrative & support | 2017 |
| Towers PUB Company Ltd | Hospitality | 2014 |
| Tradewell Services Ltd | Information & communication | 2025 |
| Transform Financial Consulting Limited | Professional & scientific | 2018 |
| Travel by Sarah Louise Ltd | Administrative & support | 2021 |
| Trem-Y-Twr Management Company Ltd | Households | 2019 |
| Tresco Ventures Ltd | Other services | 2021 |
| Trinity C P (Llandudno) Limited | Transport & logistics | 2014 |
| Trinity Properties (Wales) Limited | Extraterritorial | 2006 |
| Trinity Student Homes Limited | Real estate | 2012 |
| Triotech Property Innovations Ltd | Real estate | 2023 |
| Trulink Golf Ltd | Wholesale & retail | 2025 |
| TSC Conwy Ltd | Hospitality | 2025 |
| TU Hwnt I'R Bont Limited | Hospitality | 2017 |
| Tudno Developments Limited | Construction | 2016 |
| Tudno Health & Wellbeing Hub Ltd | Health & social care | 2018 |
| Tudno Properties Limited | Hospitality | 2000 |
| Tuscan Fine Foods Limited | Hospitality | 2017 |
| Twiltex Manufacturing Company Limited | Wholesale & retail | 1976 |
| TŶ Glân Community Care CIC | Administrative & support | 2026 |
| Uckers Limited | Professional & scientific | 1992 |
| UK Air Suspension Ltd | Wholesale & retail | 2014 |
| UK CD Transport Ltd | Transport & logistics | 2013 |
| UK Conventions Limited | Arts & recreation | 2001 |
| UK Corporate Training Limited | Administrative & support | 2012 |
| UK. IFN Ltd. | Real estate | 2005 |
| Urban Street Grill Ltd | Hospitality | 2026 |
| UTAK9 Ltd | Wholesale & retail | 2025 |
| Vale Nolan Ltd | Extraterritorial | 2018 |
| Vally Properties Limited | Households | 2025 |
| Vantore Ltd | Wholesale & retail | 2026 |
| Vaughan House RTM Company Limited | Extraterritorial | 2014 |
| Vaughan Investments (Llandudno) Limited | Construction | 2017 |
| Vehicles for Leisure Limited | Wholesale & retail | 2012 |
| Vernon Oliver Consulting Limited | Professional & scientific | 2011 |
| Victoria Club (Craig-Y-Don) Limited | Hospitality | 1929 |
| View From Construction Ltd | Construction | 2012 |
| Villagevenue(Org) Ltd | Administrative & support | 2012 |
| W.W. Flooring Ltd | Wholesale & retail | 2006 |
| Walls Residential Care Home Ltd | Health & social care | 2011 |
| Wanderin Weenies Ltd | Agriculture & fishing | 2025 |
| Wandering Holidays Limited | Hospitality | 2016 |