| Sussex Windows & Construction Ltd | Construction | 2024 |
| Sussex Windows Ltd | Construction | 2025 |
| Sussexfurs CIC | Arts & recreation | 2026 |
| Sutherland Ltd | Wholesale & retail | 2023 |
| Sutton Court Associates Limited | Health & social care | 2003 |
| Sutton Court Homes Limited | Health & social care | 1998 |
| Sutton Roofing Specialists Limited | Construction | 2020 |
| Sutton Roofing Specialists London Limited | Construction | 2022 |
| Suwo Films Ltd | Information & communication | 2021 |
| SVG 511 RTM Company Limited | Extraterritorial | 2025 |
| Svop Ltd | Information & communication | 2024 |
| SW (Finance) I PLC | Financial services | 2021 |
| SW (Finance) II Limited | Financial services | 2021 |
| SW96 Limited | Professional & scientific | 2025 |
| Swain Construction Southern Ltd | Construction | 2020 |
| Swan Digital Limited | Wholesale & retail | 2011 |
| Sweejtech Limited | Information & communication | 2022 |
| Sweeney Todd's Hairdressers Ltd | Other services | 2012 |
| Sweet Justice Sound Limited | Information & communication | 2015 |
| Sweet Tooth Games Ltd | Information & communication | 2018 |
| Sweetpea Limited | Hospitality | 2019 |
| Sweetwater Holdings Limited | Other services | 2019 |
| Swift Build Sussex Ltd | Construction | 2026 |
| Swift Property South Limited | Construction | 2020 |
| Switch and Flow Ltd | Construction | 2026 |
| Switched Maintenance Services Limited | Construction | 2022 |
| SWL Male Grooming Ltd | Extraterritorial | 2025 |
| SWS Group Holdings Limited | Professional & scientific | 2001 |
| SWS Holdings Limited | Professional & scientific | 2001 |
| Syberacquisition Ltd | Professional & scientific | 2024 |
| Sydney James Recruitment Ltd | Administrative & support | 2015 |
| Sylvan Oak U.K. Ltd | Hospitality | 2012 |
| Synergie Estates Limited | Construction | 2008 |
| Synthetic Saga Studio Ltd | Information & communication | 2025 |
| Syntiro Limited | Professional & scientific | 2002 |
| Synx Media Ltd | Information & communication | 2017 |
| System Aqua Ltd | Construction | 2017 |
| System Design Audio Limited | Other services | 2015 |
| System Engineering Consulting Limited | Administrative & support | 2011 |
| Systemroute Limited | Other services | 1995 |
| Systems Coaching Ltd | Information & communication | 2021 |
| Syzofx Ltd | Information & communication | 2023 |
| T & F Maio Property Group Ltd | Real estate | 2021 |
| T & T Environmental Ltd | Professional & scientific | 2017 |
| T Lewis Holdings Limited | Financial services | 2023 |
| T Whitelegg & Sons Ltd | Hospitality | 2025 |
| T&A Hospitality Limited | Hospitality | 2024 |
| T&G Building Solutions Ltd | Construction | 2025 |
| T&G Investments Limited | Information & communication | 2010 |
| T&G Prestige Refurbishment Ltd | Construction | 2015 |
| T. Booty Ltd | Construction | 2000 |
| T. C. G. Associates Limited | Administrative & support | 2006 |
| T. M. Electronics (U.K.) Limited | Manufacturing | 1988 |
| T. Stace & Sons Ltd | Real estate | 2014 |
| T.H. Property Lettings Ltd | Real estate | 2026 |
| T3M Management Ltd | Information & communication | 2022 |
| TA Property Developments Limited | Real estate | 2021 |
| TA Property Holdings Limited | Financial services | 2021 |
| TAB Electricians Limited | Construction | 2022 |
| Tacad Ltd | Administrative & support | 2025 |
| Tacklebox Mail Order Ltd | Agriculture & fishing | 2016 |
| Taco Look at ME NOW Ltd | Hospitality | 2020 |
| Tahmeed Limited | Hospitality | 2024 |
| Tailor Made Products Ltd | Information & communication | 2024 |
| Tailor Made Radio Limited | Information & communication | 2004 |
| Tailored Homes and Lettings Ltd | Real estate | 2021 |
| Tailored Test Solutions Limited | Manufacturing | 1999 |
| Tailspin Films Ltd | Information & communication | 2018 |
| Talent Management (WS) Limited | Other services | 2018 |
| Tall Oak Property Ltd | Construction | 2021 |
| Talos Roofing Ltd | Construction | 2024 |
| Tamar Valley Camping Limited | Hospitality | 2014 |
| Tandyuk Servers Limited | Information & communication | 2012 |
| Tango Bravo Property Limited | Real estate | 2021 |
| Tanjong Public Limited Company | Professional & scientific | 1926 |
| Tank Global Ltd | Wholesale & retail | 2014 |
| Tank US LLP | | 2021 |
| Tank Worldwide Ltd | Administrative & support | 2015 |
| Tantaline Limited | Real estate | 2006 |
| TAP and Pour Limited | Hospitality | 2024 |
| TAP Factory Productions Limited | Arts & recreation | 2012 |
| TAP House Shoreham Ltd | Hospitality | 2017 |
| Tapmagician Limited | Wholesale & retail | 2012 |
| Taptra Limited | Extraterritorial | 2010 |
| Tara Developments (Sussex) Limited | Construction | 2022 |
| Tara Fitzgerald Ltd | Arts & recreation | 2007 |
| Tara Holdings (Sussex) Limited | Financial services | 2017 |
| Tara Property Rentals Limited | Real estate | 2022 |
| Tarring Community Holdings Limited | Financial services | 2017 |
| Tarring Dental Limited | Health & social care | 2007 |
| Tarring Road RTM Company Limited | Households | 2023 |
| Tarring Scaffolding Ltd | Construction | 2015 |
| Tarring Village Inns Ltd | Wholesale & retail | 2009 |
| Tartan OWL Ltd | Information & communication | 2015 |
| Tashbloom Productions Ltd | Information & communication | 2016 |
| Taste Provence Limited | Information & communication | 2006 |
| Tatts Freehold Ltd | Real estate | 2011 |
| Taurus Consulting Ltd | Professional & scientific | 2025 |
| Taurus Recruitment Ltd | Administrative & support | 2021 |
| Tavco Travel Limited | Administrative & support | 2016 |