| Synergy Holdings Sussex Limited | Administrative & support | 2013 |
| Syntech Systems Limited | Information & communication | 2001 |
| Syntergis Ltd | Professional & scientific | 2022 |
| Syred Limited | Construction | 2009 |
| T & G Drylining Limited | Construction | 2008 |
| T & L Commercial Investments Limited | Administrative & support | 2011 |
| T & L Holdings (Hove) Ltd | Administrative & support | 2012 |
| T & S Enterprises (London) Limited | Wholesale & retail | 1999 |
| T D Worrell Ltd | Construction | 2014 |
| T K Installations Limited | Construction | 1997 |
| T Maurice Regen Ltd | Construction | 2025 |
| T S Environment Ltd | Professional & scientific | 2019 |
| T&D Design Labs Limited | Professional & scientific | 2019 |
| T&T Hove Station Car Wash Ltd | Wholesale & retail | 2017 |
| T. G. Fruits Ltd | Wholesale & retail | 2012 |
| T.C.S. Southern Ltd | Real estate | 2025 |
| T.I. Consultancy LLP | | 2016 |
| T.N.P Logistics Ltd | Transport & logistics | 2023 |
| T.W. Sibley (Farms) Limited | Agriculture & fishing | 1970 |
| T3LIVE Ltd | Professional & scientific | 2025 |
| TA Holdings Group Ltd | Real estate | 2021 |
| Tabtime Limited | Wholesale & retail | 2001 |
| Tackle Africa | Health & social care | 2010 |
| Tacs Games Limited | Information & communication | 2014 |
| Tadele Travel Limited | Administrative & support | 2015 |
| Tador (UK) Limited | Wholesale & retail | 2017 |
| Tadsum Ltd | Financial services | 2012 |
| Tafam Ltd | Transport & logistics | 2023 |
| TAG Dental Limited | Health & social care | 2026 |
| Tailwind Investments Limited | Professional & scientific | 2011 |
| Taipan Finance Limited | Real estate | 2009 |
| Taipan Holdings Limited | Real estate | 2009 |
| Taipan Investments Limited | Real estate | 2009 |
| Taipan Properties Limited | Real estate | 2009 |
| Taipan Trustees Limited | Real estate | 2009 |
| Tajdid Ltd | Real estate | 2025 |
| Take the Space Theatre Company Ltd | Arts & recreation | 2017 |
| Taksnet Limited | Information & communication | 2011 |
| Talaat Atiya & Daughters Limited | Hospitality | 2019 |
| Talay HR Consulting Limited | Financial services | 2021 |
| Talbot Associates Ltd | Other services | 2021 |
| Talent Status Group Ltd | Arts & recreation | 2016 |
| Tales of ME Ltd | Wholesale & retail | 2019 |
| Talk Share Grow Ltd | Health & social care | 2023 |
| Tall Oaks Management Company Limited | Households | 2003 |
| Tamara Vodden Limited | Professional & scientific | 2019 |
| Tamarchan Limited | Hospitality | 2020 |
| Tambourine Group Ltd | Wholesale & retail | 2021 |
| Tame Nutrition Ltd | Wholesale & retail | 2022 |
| Taming Tigers Limited | Administrative & support | 2007 |
| Taminoproductions Ltd | Arts & recreation | 2017 |
| Tammy Rennie Physiotherapy Limited | Health & social care | 2015 |
| Tamworth Logistics Ltd | Transport & logistics | 2024 |
| Tanamera Consulting Ltd | Professional & scientific | 2023 |
| Tandemonium Partners Limited | Professional & scientific | 2025 |
| Tanguy UK Limited | Information & communication | 2010 |
| Tanim Express Limited | Hospitality | 2018 |
| Tankus the Henge Ltd | Information & communication | 2019 |
| Tanner Construction (Sussex) Ltd | Construction | 2023 |
| Tanner Construction Services Ltd | Construction | 2026 |
| TAP2PARK Ltd | Information & communication | 2022 |
| Tapwells Limited | Information & communication | 1989 |
| Tardi Group Ltd | Professional & scientific | 2025 |
| Target Services Limited | Wholesale & retail | 1994 |
| Tarragon Properties Limited | Real estate | 2001 |
| Tarumbo Ltd | Hospitality | 2018 |
| Tasker Compliance Limited | Professional & scientific | 2025 |
| Taskplan Limited | Extraterritorial | 2009 |
| Taste of INDIA2 ( Brighton ) Limited | Extraterritorial | 2019 |
| Tasty Nosh Hove Ltd | Hospitality | 2025 |
| Tatangab Ltd | Real estate | 2019 |
| Taxi to Go Ltd | Transport & logistics | 2025 |
| Taylor Made Interiors (UK) Ltd | Construction | 2012 |
| Taylor Made Media Productions Limited | Information & communication | 2016 |
| Taylor Miles Building & Property Maintenance Ltd | Construction | 2024 |
| TAZ Psychology Ltd | Health & social care | 2024 |
| TC Holdings & Lettings Ltd | Real estate | 2025 |
| TCG Bling Ltd | Manufacturing | 2023 |
| TCG Garage Limited | Wholesale & retail | 2025 |
| Tchq Ltd | Information & communication | 2026 |
| Tcipatent Limited | Information & communication | 2009 |
| Tcmm International Limited | Professional & scientific | 2006 |
| TD Global Consulting Ltd | Professional & scientific | 2020 |
| TDL White Limited | Information & communication | 2024 |
| TDP Mariner Point Limited | Real estate | 2021 |
| Team 61 Ltd | Information & communication | 2021 |
| Team Audio Ltd | Administrative & support | 2012 |
| Team Communications International Limited | Other services | 1999 |
| Team Thinking Limited | Professional & scientific | 2010 |
| Teamz Ltd | Information & communication | 2020 |
| Teapot Offices Ltd | Real estate | 2019 |
| Teapot Press Limited | Information & communication | 2001 |
| Teba Food (Brighton) Limited | Wholesale & retail | 2014 |
| Teba Food Online Ltd | Wholesale & retail | 2017 |
| Teba Land Ltd | Wholesale & retail | 2025 |
| Teba Sweets Ltd | Wholesale & retail | 2024 |
| TEC Dent Ltd | Health & social care | 2023 |
| Tech Circus Meetups Ltd | Administrative & support | 2016 |
| Tech Djinn Solutions Ltd | Information & communication | 2020 |
| Tech Music Schools Limited | Education | 2010 |