| T-W-M Associates Ltd | Professional & scientific | 2019 |
| T. Hoare Engineering Ltd. | Professional & scientific | 2020 |
| T.C.W. Fire Safety Consultancy Limited | Public administration | 2026 |
| T.Kavanagh Rigging Solutions Ltd | Construction | 2025 |
| T.L Lettings Ltd | Other services | 2019 |
| T.M. Taylor & Sons Limited | Other services | 1992 |
| T.W Rigging Ltd | Information & communication | 2020 |
| T.W. Tilers (Newport) Limited | Wholesale & retail | 1987 |
| T.W. Tilers Limited | Wholesale & retail | 1964 |
| T1 Yorozuya Ltd | Wholesale & retail | 2024 |
| T10 Football Coaching Limited | Arts & recreation | 2024 |
| T1155 Limited | Construction | 1990 |
| T8 Properties Ltd | Extraterritorial | 2023 |
| Taaaap Limited | Administrative & support | 2012 |
| Tabs Homes Ltd | Households | 2025 |
| Tacteg Ltd | Manufacturing | 2025 |
| TAD Accommodation Ltd | Real estate | 2025 |
| TAD Homes Ltd | Construction | 2024 |
| Taek.Legal Limited | Professional & scientific | 2023 |
| TAF Industrial Ltd | Manufacturing | 2022 |
| Tafe Advanced AG Solutions Limited | Professional & scientific | 2021 |
| Taffys Healthcare Limited | Health & social care | 2019 |
| Tafs Garden Co Ltd | Wholesale & retail | 2020 |
| TAI Brynderi LLP | | 2024 |
| Taigh Properties Ltd | Real estate | 2023 |
| Tajveer Stores Ltd | Wholesale & retail | 2025 |
| Takeaway Tonight Limited | Hospitality | 2026 |
| Taketwominutes Ltd | Information & communication | 2025 |
| Talbot-Owen Limited | Wholesale & retail | 1974 |
| Talent Acquisition Pods Ltd | Administrative & support | 2025 |
| Talibri Kids Wear Ltd. | Manufacturing | 2016 |
| Talink Ltd | Information & communication | 2016 |
| Talink UK Consulting and IT Services Limited | Information & communication | 2023 |
| Talkative Ltd | Information & communication | 2015 |
| Talkback Communications (South Wales) Ltd | Wholesale & retail | 2002 |
| Tally HO Bouldon Ltd | Hospitality | 2017 |
| Talu Studios Ltd | Information & communication | 2025 |
| Tamarind (Ponty) Ltd | Hospitality | 2025 |
| TAMARIND86 Limited | Hospitality | 2023 |
| Tamarindnewport Ltd | Hospitality | 2025 |
| Tambar Limited | Administrative & support | 2021 |
| Tamexpress Ltd | Hospitality | 2018 |
| TAN Lines Ltd | Other services | 2017 |
| Tanbank Garage (Shropshire) Ltd | Administrative & support | 2010 |
| Tandem Transport Limited | Transport & logistics | 2010 |
| Taner Halil Ltd | Other services | 2018 |
| Tango Electrical Services Ltd | Construction | 2024 |
| Tankology Services Ltd | Construction | 2023 |
| Tanner Body Repairs Limited | Wholesale & retail | 2015 |
| Tanner Commissioning Services Limited | Construction | 2015 |
| Tanya Hair & Wellness Ltd | Other services | 2023 |
| Tape Street Inns Limited | Hospitality | 2017 |
| Taranacorp Limited | Construction | 2017 |
| Tarbed Limited | Professional & scientific | 2009 |
| Target Group Limited | Information & communication | 1975 |
| Target Servicing Limited | Information & communication | 2005 |
| Targeted Performance Initiatives Ltd | Administrative & support | 2013 |
| Taro Padel Ltd | Wholesale & retail | 2025 |
| Tarsain Holdings Ltd | Financial services | 2022 |
| Tarsain Limited | Real estate | 2018 |
| Tarsain Properties Limited | Real estate | 2026 |
| TAS Development Consultancy Limited | Real estate | 2004 |
| Task Trades Holdings Ltd | Construction | 2023 |
| Task Trades Ltd | Construction | 2022 |
| Taste Africa Limited | Wholesale & retail | 2025 |
| Taste of Paradise Midlands Limited | Hospitality | 2017 |
| Taste of the MED Ltd | Hospitality | 2025 |
| Tasty Foods Stop Ltd | Hospitality | 2023 |
| Tasty Treats Trading Co Limited | Hospitality | 2023 |
| TAU Transport Ltd | Transport & logistics | 2024 |
| Tauvera Ltd | Professional & scientific | 2023 |
| Tav&Ev Ltd | Transport & logistics | 2020 |
| Tavern Girls 3 Ltd | Hospitality | 2023 |
| Tax House (Newport) Limited | Professional & scientific | 2023 |
| Taxellence Limited | Professional & scientific | 2023 |
| Taxhouse Accountants Ltd | Professional & scientific | 2025 |
| Tayberry Close Management Company Limited | Households | 2020 |
| Tayberry House Management Company Limited | Households | 2018 |
| Taylor & Long Plumbing & Heating Ltd | Construction | 2017 |
| Taylor Civil Engineering & Plant Sales Ltd | Construction | 2026 |
| Taylor Events Limited | Arts & recreation | 2012 |
| Taylor Made Energy Solutions Ltd | Professional & scientific | 2010 |
| Taylor Power Environmental Limited | Construction | 1997 |
| Taylor Print Media Limited | Manufacturing | 2014 |
| Taylor Residential Lettings Limited | Households | 2023 |
| Taylor Wade Limited | Real estate | 2006 |
| Taylor Windscreens Ltd | Wholesale & retail | 2019 |
| Taylor's Housing Company Ltd | Real estate | 2026 |
| Taylorfield Group Ltd | Administrative & support | 2026 |
| Taylorhare Architects Ltd | Professional & scientific | 2017 |
| Taylors Motor Company Ltd | Wholesale & retail | 2016 |
| Tazana Ltd | Hospitality | 2022 |
| TBH Equity Holdings Ltd | Financial services | 2025 |
| TBM Consultancy Services Limited | Professional & scientific | 2022 |
| TBQ Eatery Limited | Hospitality | 2025 |
| TC Car Sales Limited | Wholesale & retail | 2021 |
| TC Competitions Limited | Wholesale & retail | 2024 |
| TC Global Blade Repairs Limited | Manufacturing | 2025 |
| TC Holdings Group Limited | Financial services | 2025 |
| TC Investment Properties Limited | Real estate | 2025 |