| Thehappygarden Ltd | Wholesale & retail | 2024 |
| Therapy Thai Limited | Health & social care | 2024 |
| Theresa Austin Consulting Limited | Professional & scientific | 2009 |
| Theseus Bidco Limited | Financial services | 2026 |
| Thetaphi Ltd | Manufacturing | 2023 |
| Theworkpeople Ltd. | Information & communication | 2025 |
| Think Corporate Reporting Limited | Professional & scientific | 1994 |
| Think Together Ltd | Professional & scientific | 2023 |
| Third Kind Games Limited | Information & communication | 2016 |
| This Girl Runs Ltd | Education | 2017 |
| Thistle & Country Limited | Wholesale & retail | 2026 |
| Thomas James Construction Limited | Manufacturing | 2023 |
| Thorburns Ltd | Wholesale & retail | 2000 |
| Thorburns Menswear Ltd | Extraterritorial | 2012 |
| Thornby Digital Limited | Administrative & support | 2022 |
| Thorpe Mews Management Company Limited | Households | 1995 |
| Three Arch Bridge Property Services Ltd | Real estate | 2025 |
| Three Chickens Investments Limited | Real estate | 2025 |
| Three Counties Car Storage Limited | Transport & logistics | 2022 |
| Three Direct Services Limited | Information & communication | 2025 |
| Threshold Technologies Ltd | Information & communication | 2026 |
| Thrive Careers Ltd | Wholesale & retail | 2010 |
| Thriving Edge Properties Limited | Financial services | 2023 |
| Through My TV Limited | Information & communication | 2011 |
| Thryvana Ltd | Professional & scientific | 2024 |
| Thwaites Limited | Manufacturing | 1944 |
| Ticra Limited | Hospitality | 2024 |
| Tiddington Limited | Professional & scientific | 2013 |
| Tiddlers Limited | Hospitality | 2023 |
| Tiger Mill Media Ltd | Professional & scientific | 2019 |
| Tigs Old Bits Limited | Other services | 2018 |
| Tile and Stone Medic Limited | Administrative & support | 2006 |
| Tile Traders (Midlands) Limited | Construction | 2018 |
| Tilia House Management Limited | Administrative & support | 2026 |
| Tilly Trotter's Brides Limited | Wholesale & retail | 2014 |
| TIM Watts Services Ltd | Professional & scientific | 2024 |
| Timber Digital Limited | Information & communication | 2020 |
| Timberstore Limited | Manufacturing | 2014 |
| Timberstore Rowfant Limited | Manufacturing | 2014 |
| Time to Pause Mwhc Ltd | Health & social care | 2024 |
| Timeflow Property Services Limited | Real estate | 2009 |
| Timms Window Cleaning Limited | Administrative & support | 2016 |
| Tina Martin Ltd | Professional & scientific | 2012 |
| Tina Martin Properties Limited | Real estate | 2015 |
| Tingling Design Ltd | Information & communication | 2021 |
| Tinz Limited | Energy | 2020 |
| Tinz Programme 1 Holdco Limited | Energy | 2020 |
| Tinz Programme 1 Projectco 1 Limited | Energy | 2020 |
| Tinz Programme 1 Projectco 2 Limited | Energy | 2020 |
| Tinz Programme 2 Holdco Limited | Energy | 2021 |
| Tinz Programme 2 Projectco 1 Limited | Energy | 2021 |
| Tinz Programme 2 Projectco 2 Limited | Energy | 2021 |
| Tinz Programme 2 Projectco 3 Limited | Energy | 2021 |
| Tinz Programme 2 Projectco 4 Limited | Energy | 2021 |
| Tinz Programme 3 Holdco Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 1 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 2 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 3 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 4 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 5 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 6 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 7 Limited | Energy | 2021 |
| Tinz Programme 3 Projectco 8 Limited | Energy | 2021 |
| Titan Corporation Ltd | Administrative & support | 2021 |
| TJN Property Ltd | Real estate | 2019 |
| TK Electrical Solutions Ltd | Extraterritorial | 2022 |
| TKG Luna Limited | Information & communication | 2023 |
| TKP (Midland) Services Ltd | Manufacturing | 2011 |
| TKT Royal Leamington Spa Cheer & Dance Ltd | Education | 2025 |
| TLA Research Limited | Professional & scientific | 2011 |
| TLC Engineering Limited | Administrative & support | 2007 |
| Tlcbar Ltd | Wholesale & retail | 2021 |
| TLT Financial Limited | Administrative & support | 2018 |
| TM & CA Services Limited | Professional & scientific | 2026 |
| TM Active Solutions Ltd | Administrative & support | 2025 |
| TM Marketing Limited | Information & communication | 2016 |
| TMC (Tolley Motor Company) Limited | Construction | 2008 |
| TMD Catering Ltd | Hospitality | 2026 |
| TMG Investments Limited | Financial services | 1994 |
| TMG Mortimer Road Limited | Construction | 1999 |
| TMJ Accounting Services Limited | Professional & scientific | 2018 |
| TMK Developments Limited | Construction | 2005 |
| Tofate Group Ltd | Transport & logistics | 2022 |
| Toka Blue Ltd | Professional & scientific | 2024 |
| Tokenhouse Developments Ltd | Construction | 2025 |
| TOM Sykes Racing Limited | Professional & scientific | 2007 |
| TOM Wolstenholme Ltd | Administrative & support | 2019 |
| Tombobulus Games Ltd | Information & communication | 2024 |
| Tomf Ltd | Arts & recreation | 2011 |
| Tomlin & Co Ltd | Professional & scientific | 2013 |
| Tonbridge Management Company Limited | Households | 2005 |
| Tonk Digital Ltd | Extraterritorial | 2025 |
| Tonnat Holdings Ltd | Extraterritorial | 2019 |
| Tony Gous Restaurant Services Limited | Administrative & support | 2025 |
| Tony Harper Consultancy Services Limited | Professional & scientific | 2024 |
| Toor and Sons Limited | Hospitality | 2024 |
| Tootall Limited | Administrative & support | 2011 |
| Top Cloud Solutions UK Limited | Information & communication | 2020 |
| Topaz Business Solutions Limited | Professional & scientific | 2017 |
| Topaz Flex Limited | Professional & scientific | 1998 |