| Tailored for YOU Ltd | Information & communication | 2008 |
| Take 5 Snacks Limited | Hospitality | 2014 |
| Take Swift Limited | Transport & logistics | 2024 |
| Takeaway Dining Limited | Hospitality | 2021 |
| Takk Care Ltd | Health & social care | 2019 |
| Taldannash Limited | Wholesale & retail | 2020 |
| Talk Electronics Limited | Manufacturing | 1996 |
| Talkartech Ltd | Information & communication | 2019 |
| Talwandhi Consultancy Limited | Professional & scientific | 2026 |
| TAM LOG Ltd | Transport & logistics | 2023 |
| TAM Scaffolding (Swindon) Ltd | Construction | 2022 |
| Tamagi Limited | Real estate | 2025 |
| Tamah Crown Limited | Hospitality | 2021 |
| Tamed Systems Limited | Professional & scientific | 2017 |
| Tamoli Limited | Manufacturing | 2025 |
| Tamushinga Ltd | Health & social care | 2010 |
| TAN Home Refurbs Ltd | Construction | 2025 |
| Tanate Global Ltd | Information & communication | 2025 |
| Tandoori Flames Swindon Ltd | Hospitality | 2017 |
| Tangerine Segment Limited | Real estate | 2023 |
| Tangle | Arts & recreation | 2011 |
| Tangled Bank Holidays Ltd | Hospitality | 2019 |
| Tanner Leisure Ltd | Hospitality | 2022 |
| Tanning LM Ltd | Other services | 2025 |
| Tanpo Ltd | Information & communication | 2014 |
| Tanuj Legal and Immigration Services Limited | Professional & scientific | 2015 |
| Tanup Ltd | Other services | 2024 |
| Tanvir Pharm Ltd | Other services | 2021 |
| Tanwood Theatrical Appointments Ltd | Administrative & support | 2025 |
| Tanya Care Limited | Health & social care | 2013 |
| Tanya Transport Ltd | Transport & logistics | 2020 |
| TAP Attack Limited | Extraterritorial | 2010 |
| TAP Room Evolution Ltd | Extraterritorial | 2024 |
| Tara Keane Consulting Limited | Administrative & support | 2012 |
| Target Hire HR Ltd | Information & communication | 2026 |
| Target Leadership Consulting Ltd | Professional & scientific | 2019 |
| Targo Group Limited | Wholesale & retail | 2026 |
| Tariro Homes Ltd | Real estate | 2018 |
| Tariro Limited | Health & social care | 2011 |
| Tarn Logistics Ltd | Transport & logistics | 2024 |
| Tarosso Transport Limited | Transport & logistics | 2019 |
| Tarso Lopes Management Ltd | Real estate | 2018 |
| TAS Care Limited | Health & social care | 2009 |
| Tashtay (2020) Ltd | Energy | 2022 |
| Tasika Enterprises Limited | Real estate | 2021 |
| Taste of Bharat PVT Limited | Hospitality | 2025 |
| Taste of India Swindon Ltd | Hospitality | 2019 |
| Taste of Tomorrow Ltd | Hospitality | 2019 |
| Tasty's Peri Peri Limited | Hospitality | 2009 |
| Tattsync Ltd | Information & communication | 2025 |
| Tavolo Medical Solutions Limited | Administrative & support | 2023 |
| Tax Ebooks Limited | Professional & scientific | 2012 |
| Taxi Ride Limited | Transport & logistics | 2016 |
| Taxman Limited | Professional & scientific | 2021 |
| Taxtful Consulting Ltd | Information & communication | 2021 |
| Tayju Associates Limited | Construction | 2004 |
| Taylens Private Hire Ltd | Transport & logistics | 2021 |
| Taylor Arts LLP | | 2021 |
| Taylor Engineering Limited | Manufacturing | 2001 |
| Taylor Made Cleaning Ltd | Administrative & support | 2025 |
| Taylor Welding Ltd | Construction | 2015 |
| Taylored Alliance Ltd | Administrative & support | 2024 |
| TB Couriers Swindon Ltd | Transport & logistics | 2021 |
| TB Transport Limited | Transport & logistics | 2016 |
| TBA Management Ltd | Real estate | 2021 |
| Tblw Ltd | Other services | 2023 |
| TBN Services Ltd | Extraterritorial | 2016 |
| Tborowski Ltd | Transport & logistics | 2020 |
| TC Carpentry Limited | Construction | 2022 |
| TC Expert Cleaning Limited | Administrative & support | 2026 |
| TCC Coventry Ltd | Administrative & support | 2021 |
| TCG1 UK Limited | Construction | 2019 |
| Tcgrealm Limited | Wholesale & retail | 2025 |
| Tcpc Limited | Real estate | 2012 |
| TCR Haulage Ltd | Transport & logistics | 2022 |
| TCS Contracts (Swindon) Limited | Financial services | 2024 |
| TCS Contracts Holdings Limited | Financial services | 2020 |
| TDC Transport Ltd | Transport & logistics | 2018 |
| TDH Property Developments Ltd | Real estate | 2014 |
| Tdhj Ltd | Wholesale & retail | 2019 |
| TDI Driving School Ltd | Education | 2021 |
| TDP Operations Improvement Ltd | Professional & scientific | 2024 |
| TDP UK Holdings Ltd | Financial services | 2024 |
| TE Connectivity Limited | Professional & scientific | 2012 |
| TE Connectivity UK Trustee Ltd | Financial services | 2024 |
| Teach Pips Ltd | Education | 2020 |
| Teaghlach Nominees Limited | Financial services | 2020 |
| Teal Events Limited | Manufacturing | 2006 |
| Team ACG Ltd | Professional & scientific | 2024 |
| Team Anco Limited | Administrative & support | 2019 |
| Team Bubblez Ltd | Hospitality | 2025 |
| Team Lawrie Limited | Information & communication | 2010 |
| Team Oasis Ltd | Wholesale & retail | 2022 |
| Team Outram Ltd | Information & communication | 2025 |
| Team PMA Ltd | Professional & scientific | 2024 |
| Team Steam PUB Company Ltd | Hospitality | 2019 |
| Team TI Swindon Ltd | Hospitality | 2020 |
| Team-I Solutions Ltd | Professional & scientific | 2017 |
| Teamability CIC | Education | 2025 |
| Teamzara Limited | Health & social care | 2018 |