| Top Style Haircut Ltd | Other services | 2024 |
| Top Style(Worthing) Ltd | Other services | 2018 |
| Topaz Technology Ltd | Extraterritorial | 2024 |
| Topiary & Hedging UK Limited | Wholesale & retail | 2019 |
| Toplevel Computing Limited | Information & communication | 1989 |
| Toplevel Development Limited | Extraterritorial | 1983 |
| Toplevel Holdings Limited | Professional & scientific | 1996 |
| Toplevel Software Limited | Extraterritorial | 1996 |
| Topline Travel Group Limited | Extraterritorial | 2025 |
| Torbay Car Centre Limited | Professional & scientific | 1983 |
| Tortex Engineering Limited | Wholesale & retail | 1965 |
| Total Carpentry (Sussex) Ltd | Construction | 2006 |
| Total Construction (Sussex) Ltd | Construction | 2008 |
| Total Motor AID Limited | Administrative & support | 2014 |
| Total People and Culture Ltd | Administrative & support | 2026 |
| Total Site Solutions Ltd | Construction | 2017 |
| Totr Findon Limited | Wholesale & retail | 2025 |
| Touch of Magic Limited | Construction | 1994 |
| Touchstone Commercial Ltd | Financial services | 2021 |
| Touchstones Care Ltd | Health & social care | 2011 |
| Tough Mondays Coffee Ltd | Wholesale & retail | 2023 |
| Townsend Electrical Ltd | Construction | 2018 |
| Toxic Beards Ltd | Other services | 2025 |
| Toy's Flying WOK (Chichester) Ltd | Hospitality | 2013 |
| Toy's Flying WOK (Worthing) Ltd | Hospitality | 2012 |
| Tracie Bentley Ltd | Administrative & support | 2024 |
| Track TEN Software Consulting Limited | Information & communication | 2001 |
| Trade Sips Ltd | Manufacturing | 2022 |
| Tradelogic Limited | Information & communication | 2006 |
| Trademark Design and Build Limited | Construction | 2017 |
| Traderon Limited | Wholesale & retail | 2019 |
| Traders DEN Limited | Extraterritorial | 2009 |
| Tradesuite Software Solutions Ltd | Extraterritorial | 2016 |
| Trading Card Grails Ltd | Wholesale & retail | 2026 |
| Trafford Law Ltd | Professional & scientific | 2018 |
| Tramp Trading Limited | Administrative & support | 2012 |
| Trans Millennium Limited | Professional & scientific | 1998 |
| Transcend Talent Consultancy Ltd | Professional & scientific | 2016 |
| Transflow Logistics Ltd | Transport & logistics | 2019 |
| Transformative Marketing Solutions Ltd | Professional & scientific | 2014 |
| Transition Town Worthing CIC | Other services | 2017 |
| Traslyn Court Management Limited | Households | 2007 |
| Trauma Psychology Training Limited | Education | 2017 |
| Travel/On Limited | Wholesale & retail | 2025 |
| Travelling Sideshow Ltd | Information & communication | 2012 |
| TRC Hestech Limited | Professional & scientific | 2018 |
| Tree Assist Ltd | Agriculture & fishing | 2024 |
| Tree Frog Grading Limited | Wholesale & retail | 2021 |
| Trendiing Ltd | Other services | 2023 |
| Trevillion Images Ltd | Arts & recreation | 2010 |
| Tri-Tech Electrical Limited | Construction | 2009 |
| Tribewerk Ltd | Other services | 2017 |
| Tricut Engineering Limited | Manufacturing | 2009 |
| Trident Windows (Southern) Limited | Manufacturing | 2017 |
| Trinity Holdings Limited | Professional & scientific | 1998 |
| Trinity Jackson Unlimited | Real estate | 2021 |
| Trio Medicines Limited | Health & social care | 2005 |
| Triple a Event Security Ltd | Public administration | 2008 |
| Triple AAA Event Security Ltd | Administrative & support | 2021 |
| Triple J Drinks Ltd | Arts & recreation | 2025 |
| Triwonder Digital Limited | Manufacturing | 2017 |
| Triwonder Group Limited | Financial services | 2022 |
| Triwonder Systems Limited | Administrative & support | 2025 |
| Trixyblox Holdings Limited | Financial services | 2024 |
| Trixyblox Ltd | Information & communication | 2023 |
| TRL Properties Limited | Real estate | 1969 |
| Trobador Ltd | Professional & scientific | 2014 |
| Trollope Estates Limited | Households | 1983 |
| Troullos Properties Limited | Real estate | 2018 |
| Trubru Coffee Ltd | Manufacturing | 2021 |
| True Form Cleaning Ltd | Administrative & support | 2026 |
| True North Innovative Limited | Administrative & support | 2013 |
| Trust Diner Ltd | Information & communication | 2025 |
| Trust Research Services Limited | Administrative & support | 2007 |
| Trustactuarial Limited | Administrative & support | 2000 |
| Trustciso Limited | Information & communication | 2021 |
| Trustees of the L.D.S. Leak Detection Specialists EOT Limited | Extraterritorial | 2024 |
| TRW Associates Ltd | Professional & scientific | 2018 |
| TS Consulting Engineering Limited | Professional & scientific | 2023 |
| Tshedza Limited | Health & social care | 2025 |
| Tshidijoy Limited | Health & social care | 2025 |
| Ttproductions Limited | Information & communication | 2022 |
| TTS South Limited | Construction | 2023 |
| Tuatha Holdings Ltd | Financial services | 2025 |
| Tudor Design Solutions Limited | Information & communication | 2020 |
| Tugela Properties Ltd | Other services | 2007 |
| Tullett Electrical Limited | Construction | 2011 |
| Tullett Holdings Limited | Financial services | 2019 |
| Turners Barbershop Ltd | Other services | 2021 |
| Turning Tides Homelessness | Hospitality | 1992 |
| Turquoise Coast Ltd | Hospitality | 2025 |
| Tutor Hive Ltd | Education | 2018 |
| Twelve Marketing Limited | Information & communication | 2020 |
| Twelve Warrior Gardens Residents Management Company Limited | Households | 1992 |
| Twentyfourseven Electrical Ltd | Construction | 2018 |
| Twilight Group Limited | Administrative & support | 2018 |
| Twilight Sparkle Ltd | Administrative & support | 2019 |
| Twinbox Group Ltd | Construction | 2025 |
| Twineham Properties Limited | Real estate | 2022 |
| Twinpath Consultancy Limited | Professional & scientific | 2025 |