| STM Investments Limited | Real estate | 2005 |
| Stobart Transport (Sussex) Limited | Transport & logistics | 2025 |
| Stockbury Consulting Ltd | Professional & scientific | 2023 |
| Stone & Black Propco Ltd | Real estate | 2026 |
| Stoneleigh Kitchens & Developments Limited | Construction | 2019 |
| Storyboard PR Limited | Professional & scientific | 2025 |
| Strand Estate Consultancy Ltd | Construction | 2012 |
| Strategic Site Acquisitions Limited | Real estate | 2026 |
| Strawberry Field Homes CIC | Real estate | 2023 |
| Strawberry Fields Hotel Limited | Hospitality | 2016 |
| Streamz Global Limited | Manufacturing | 2010 |
| Strebor Enterprises Limited | Professional & scientific | 2006 |
| String Town Handyman Ltd. | Professional & scientific | 2024 |
| Striver Technologies Limited | Information & communication | 2025 |
| Stroppy Frog Limited | Extraterritorial | 2026 |
| Stuart LEE & Associates Limited | Professional & scientific | 2013 |
| Stud Farm Trading Limited | Professional & scientific | 1999 |
| Studio Bell Ltd | Real estate | 2025 |
| Studio Bonparte Limited | Professional & scientific | 2018 |
| Studio Steel Limited | Professional & scientific | 2022 |
| SUB Demolition & Groundworks Ltd | Construction | 2014 |
| Subterranean Games Limited | Information & communication | 2012 |
| Sudworth Medical Ltd | Health & social care | 2026 |
| Suju Projects Ltd | Professional & scientific | 2024 |
| Summersbybrown Ltd | Hospitality | 2019 |
| Summit Coffee Limited | Extraterritorial | 2020 |
| Sunchalk Limited | Professional & scientific | 1998 |
| Suncoast Migration Limited | Professional & scientific | 2014 |
| Sunnyholme Properties Limited | Professional & scientific | 2014 |
| Superfine Chocolate Limited | Extraterritorial | 2011 |
| Superfine Confectionery Limited | Extraterritorial | 2011 |
| Superfine Foods Limited | Extraterritorial | 2011 |
| Superfine Ingredients Limited | Extraterritorial | 2011 |
| Supermarine Holdings Ltd | Financial services | 2024 |
| Surgeons LLP | | 2021 |
| Surgiplan Ltd | Information & communication | 2026 |
| Surrey Men's Health Ltd | Health & social care | 2025 |
| Sussex Arbor Pro Limited | Agriculture & fishing | 2012 |
| Sussex Auto Parts Limited | Wholesale & retail | 1993 |
| Sussex Auto Services Limited | Wholesale & retail | 1999 |
| Sussex Autos Holdings Limited | Financial services | 2021 |
| Sussex Biologicals Ltd | Manufacturing | 2014 |
| Sussex Building and Landscaping Limited | Construction | 2011 |
| Sussex Business Online Limited | Extraterritorial | 2012 |
| Sussex by the Sea Limited | Wholesale & retail | 2019 |
| Sussex Chicken Ltd | Hospitality | 2014 |
| Sussex Commerce Limited | Information & communication | 2009 |
| Sussex Community Stores Ltd | Wholesale & retail | 2019 |
| Sussex Country Cottages Ltd | Real estate | 2017 |
| Sussex Essentials Ltd | Wholesale & retail | 2020 |
| Sussex Housing Limited | Real estate | 2020 |
| Sussex KBB Ltd | Construction | 2025 |
| Sussex Men's Health Ltd | Health & social care | 2025 |
| Sussex Oak Products Ltd | Manufacturing | 2021 |
| Sussex Repointing Specialists Ltd | Construction | 2021 |
| Sussex Skills 4 U Ltd | Education | 2023 |
| Sussex Stone & Ceramic Limited | Construction | 2013 |
| Sussex Stone Marble & Granite Limited | Manufacturing | 2005 |
| Sussex Strip and Install Ltd | Manufacturing | 2026 |
| Sussex Surgical Solutions Limited | Health & social care | 2023 |
| Sussex Weald Homes Limited | Construction | 2016 |
| Sutton (Unique) Limited | Real estate | 1958 |
| Sutton Road Developments Limited | Professional & scientific | 2011 |
| SW Holdings Sussex Limited | Financial services | 2023 |
| SW Repairs Limited | Wholesale & retail | 2024 |
| Swallow Business Park Management Company Limited | Real estate | 2016 |
| Swayth Ltd | Financial services | 2025 |
| Swaythtrading Ltd | Financial services | 2025 |
| Sweet Bakeart Ltd | Manufacturing | 2022 |
| Swift Electrics Ltd | Construction | 2020 |
| Swole Panda Limited | Wholesale & retail | 2017 |
| Sync Consulting Limited | Professional & scientific | 2026 |
| Synnovate Group Limited | Information & communication | 2023 |
| T Baker Property Renovations Ltd | Construction | 2019 |
| T Collison Construction Ltd | Construction | 2018 |
| T J Decorators Southern Limited | Construction | 2011 |
| T J Oliver & Associates Limited | Financial services | 2017 |
| T J Woodhams Ltd | Construction | 2021 |
| T&B Events Limited | Arts & recreation | 2014 |
| T&B Management Ltd | Hospitality | 2016 |
| T.M.G. Civils Ltd | Construction | 2023 |
| T2 Security Limited | Administrative & support | 2010 |
| Taggel Consulting Ltd | Professional & scientific | 2017 |
| Talwadker Consulting Limited | Health & social care | 2025 |
| Tarble Farm Ltd | Financial services | 2025 |
| Target Padel Limited | Construction | 2025 |
| Taste of the Vine Limited | Administrative & support | 1997 |
| Tayi Investments Limited | Health & social care | 2014 |
| Taylor Bennett Holdings Limited | Professional & scientific | 2004 |
| Taylor Birchwood Limited | Administrative & support | 1986 |
| Taylor Construction South East Ltd | Construction | 2015 |
| Taylor Holdings (South East) Ltd | Professional & scientific | 2019 |
| Taylor Traditional Limited | Manufacturing | 2016 |
| Taylormade Medical Limited | Health & social care | 2024 |
| Taylors Restaurant & Sports Bar Limited | Hospitality | 2019 |
| Taylor’S Fine Goods Ltd | Wholesale & retail | 2025 |
| Tbcorner Limited | Wholesale & retail | 2020 |
| TDH Wheeler Limited | Financial services | 2018 |
| Teal House Limited | Real estate | 1999 |
| Team FD Limited | Wholesale & retail | 2020 |