| Tridoor Industrial Door Services Ltd | Administrative & support | 2016 |
| Tridoor Limited | Manufacturing | 2017 |
| Trilogy Games Limited | Arts & recreation | 2025 |
| Trinity Heating Solutions Ltd | Construction | 2018 |
| Trinity Tankers (Barnsley) Ltd | Transport & logistics | 2025 |
| Trinity’S Antiques Limited | Wholesale & retail | 2025 |
| Triple Fast Ltd | Transport & logistics | 2018 |
| Triple H Construction Ltd | Construction | 2024 |
| Triple H Rentals Limited | Real estate | 2024 |
| Triple M Vehicles Ltd | Wholesale & retail | 2012 |
| Triple Nest Lettings Ltd | Real estate | 2025 |
| Triten International Limited | Professional & scientific | 2016 |
| Troopfill Limited | | 1987 |
| Tru-Wall Ltd | Administrative & support | 2019 |
| True Drive Ltd | Transport & logistics | 2017 |
| True Grips Group Ltd | Wholesale & retail | 2025 |
| True Maverick Media Ltd | Professional & scientific | 2018 |
| True-Weld Limited | Manufacturing | 2022 |
| Trueagra Limited | Transport & logistics | 2013 |
| Truly Inc Group Enterprises Ltd | Administrative & support | 2021 |
| Trust Home Care Ltd | Health & social care | 2016 |
| Trusted Mortgage & Protection Advisors Ltd | Financial services | 2023 |
| Trustlet Ltd | Construction | 2013 |
| Trustsport | Wholesale & retail | 2006 |
| Trustwell Drives & Patios Ltd | Administrative & support | 2025 |
| TS Civil Engineering & Utilities Ltd | Construction | 2019 |
| TS Print and Embroidery Limited | Manufacturing | 2025 |
| TS Training Services Limited | Education | 2021 |
| TS9TRANSPORT Ltd | Transport & logistics | 2025 |
| Tsak Foods Ltd | Hospitality | 2025 |
| TSJ Smile Limited | Health & social care | 2011 |
| TSM Hire Ltd | Administrative & support | 2022 |
| TSN Foods Ltd | Wholesale & retail | 2020 |
| TSN Group Property Ltd | Real estate | 2025 |
| Tsoa York Limited | Wholesale & retail | 2024 |
| Tstone Psychology Ltd | Health & social care | 2025 |
| Tsubaki Translations Limited | Professional & scientific | 2011 |
| Tsunami Investments Limited | Financial services | 2025 |
| TSW UK Properties Ltd | Real estate | 2020 |
| TT Electrical Services Ltd | Construction | 2024 |
| Tt&S Solutions Ltd | Administrative & support | 2024 |
| TTN Properties Ltd | Real estate | 2025 |
| Tubecon Limited | Manufacturing | 2010 |
| Tudortransport Ltd | Transport & logistics | 2026 |
| TUE Farming Ltd | Agriculture & fishing | 2020 |
| Tuff Doors Ltd | Financial services | 2017 |
| Tuff Property Ltd | Real estate | 2023 |
| Tuff Workwear Ltd | Wholesale & retail | 2011 |
| Tuffpipes Limited | Manufacturing | 2006 |
| Tuganet Limited | Information & communication | 2008 |
| Tuke Electrical Services Ltd | Construction | 2020 |
| Tulloch - Gray Properties Limited | Real estate | 2025 |
| Tumbling Lane Management Company Limited | Households | 2025 |
| Tumiru Ltd | Transport & logistics | 2021 |
| Tunay Limited | Wholesale & retail | 2018 |
| Turbo Precision Engineering Ltd | Professional & scientific | 2013 |
| Turbo Solutions Ltd | Professional & scientific | 2005 |
| Turner Signs Limited | Administrative & support | 2002 |
| Turnkey Vehicle Solutions Ltd | Wholesale & retail | 2024 |
| Turrim Estate Ltd | Real estate | 2024 |
| Tuscan Gardens (Doncaster Road Barnsley) Management Company Limited | Real estate | 2004 |
| TVS Europe Distribution Limited | Financial services | 2011 |
| TWC Consulting Ltd | Professional & scientific | 2020 |
| Tweaky TV Limited | Financial services | 2025 |
| Tweed & Groom Limited | Wholesale & retail | 2020 |
| Twelve Monkeys Ltd | Hospitality | 2018 |
| Twenty Twenty at Kingswood Park Management Limited | Professional & scientific | 2006 |
| Twiggs Grounds Maintenance Ltd | Administrative & support | 2014 |
| Twiggs Properties Ltd | Real estate | 2020 |
| Twigpro Ltd | Information & communication | 2022 |
| Twin Hammer Investments Limited | Financial services | 2022 |
| Twist & Style Beds Limited | Wholesale & retail | 2018 |
| Twist & Style Limited | Wholesale & retail | 2013 |
| Twist on Twenty Ltd | Wholesale & retail | 2024 |
| Twisted Gigolo Media Ltd | Professional & scientific | 2014 |
| Twnsnd Limited | Information & communication | 2022 |
| Two Gates Fisheries Ltd. | Hospitality | 2016 |
| Two Guys Retail Limited | Wholesale & retail | 2025 |
| Two Short Planks Ltd | Administrative & support | 2017 |
| Two Wheel Nation Limited | Wholesale & retail | 2020 |
| TWS Broadcast Limited | Information & communication | 2017 |
| Twwsy Limited | Hospitality | 2012 |
| Ty.Isherwood Limited | Arts & recreation | 2025 |
| Tykes Chippy Ltd | Hospitality | 2014 |
| Tylr Limited | Information & communication | 2017 |
| Tynebor Ltd | Construction | 2024 |
| Tzaszlos Ltd | Construction | 2024 |
| Tzuk Ltd | Transport & logistics | 2016 |
| Udisteanu Ltd | Transport & logistics | 2018 |
| UFO Burgers & Pancakes Limited | Wholesale & retail | 2025 |
| UK Air Comms Ltd | Information & communication | 2015 |
| UK Car Credit Limited | Financial services | 2025 |
| UK Carpet Wholesale Ltd | Wholesale & retail | 2015 |
| UK Carpets Wholesalers Limited | Wholesale & retail | 2020 |
| UK Electrical Testing and Maintenance Ltd | Construction | 2020 |
| UK Envy Ltd | Wholesale & retail | 2024 |
| UK Home Development Limited | Construction | 2025 |
| UK Lesiure Ltd | Wholesale & retail | 2009 |
| UK Orchid Holdings Limited | Financial services | 2025 |
| UK Solar Supplies Ltd | Wholesale & retail | 2024 |