| Sstl Limited | Arts & recreation | 2021 |
| ST Catherine's Hospice Trading (Sussex) Limited | Wholesale & retail | 1993 |
| ST Innovation Ltd | Wholesale & retail | 2023 |
| ST James Engineering Limited | Administrative & support | 2013 |
| ST Omer Residential Care Limited | Health & social care | 2023 |
| ST. Athanasius Limited | Health & social care | 2014 |
| ST. Barnabas Court Management Company Limited | Households | 1986 |
| ST. Catherine's Hospice Limited | Public administration | 1980 |
| ST. Mary PVT Ltd | Health & social care | 2024 |
| Staeng Limited | Manufacturing | 1974 |
| Staffbank Recruitment Limited | Administrative & support | 2001 |
| Staffworx Limited | Administrative & support | 2007 |
| Stage Ready Limited | Arts & recreation | 2024 |
| Stainless DID IT Ltd | Other services | 2025 |
| Stair and Banister Ltd | Manufacturing | 2019 |
| Stairs & Banisters Ltd | Manufacturing | 2024 |
| Staniszewski & Richter Limited | Other services | 1994 |
| Star Auto Clinic Ltd | Wholesale & retail | 2019 |
| Star Cars (Gatwick) Ltd | Other services | 2010 |
| Star Fresh UK Limited | Construction | 2016 |
| Star Interiors Limited | Wholesale & retail | 2003 |
| Star-Tastic Academy Limited | Education | 2023 |
| Star-Tastic Camps Limited | Arts & recreation | 2021 |
| Star-Tastic Clothing Limited | Wholesale & retail | 2023 |
| Star-Tastic CPD Limited | Other services | 2017 |
| Star-Tastic Gymnastic Limited | Education | 2017 |
| Star-Tastic Powerhouse Parkour Limited | Education | 2022 |
| Stark Future Limited | Professional & scientific | 2023 |
| Starlet Real Estate Limited | Real estate | 2017 |
| Starlight Fragrance Ltd | Wholesale & retail | 2025 |
| Starmakers Ltd | Arts & recreation | 2025 |
| Starmill Properties Limited | Real estate | 2002 |
| Start (UK) Limited | Administrative & support | 1997 |
| Staupe Engineering Limited | Administrative & support | 2007 |
| Stawbud Limited | Administrative & support | 2014 |
| Stay D Luxe Ltd | Real estate | 2026 |
| Stay Sharp Cleaning Services Limited | Administrative & support | 2021 |
| Staybeyond Limited | Hospitality | 2016 |
| STB Aesthetics Ltd | Other services | 2026 |
| Stco Food and Beverages Ltd | Hospitality | 2024 |
| Stealth Secure Ltd | Administrative & support | 2024 |
| Stebbington Ltd | Public administration | 2021 |
| Steck Depositors Trustees Limited | Financial services | 2025 |
| Stedking Ltd | Professional & scientific | 2025 |
| Steel Calculation Designs Ltd | Professional & scientific | 2014 |
| Steer & Sons Ltd | Construction | 2023 |
| Stefanovici Limited | Construction | 2018 |
| Stellar Aero Ltd | Manufacturing | 2023 |
| Stellar Square Limited | Real estate | 2023 |
| Stephen Mansell Racing Ltd | Arts & recreation | 1995 |
| Stephen Wilkinson Spreadsheet Solutions Ltd | Information & communication | 2016 |
| Stephens & Carter Limited | Professional & scientific | 1912 |
| Stepped Solutions Ltd | Construction | 2025 |
| Steptidy Ltd | Other services | 2025 |
| Sterling and Crest Limited | Manufacturing | 2025 |
| Sterling Consultancies Limited | Information & communication | 2014 |
| Sterling Realty London Ltd | Households | 2026 |
| Steve Braithwaite DJ Entertainment Limited | Arts & recreation | 2019 |
| Steve Meekin Transport Ltd | Transport & logistics | 2006 |
| Steve Nicholson Property Services Limited | Administrative & support | 2016 |
| Stevens Dunn Housing Ltd | Real estate | 2023 |
| Stevens Property Partners Limited | Construction | 2018 |
| Stevensdrake Limited | Professional & scientific | 2010 |
| Steyning Dental Care Limited | Health & social care | 2010 |
| STF Technology Ltd | Information & communication | 2025 |
| STK92 Limited | Professional & scientific | 2020 |
| STM Cargo Specialist Ltd | Transport & logistics | 2017 |
| Stodel Ltd | Transport & logistics | 2015 |
| Stoke Newington Dental Care Ltd | Health & social care | 2011 |
| Stoke Wood Events Ltd | Arts & recreation | 2022 |
| Stone Cross Dental Care Limited | Health & social care | 2007 |
| Stonebridge Investments Sussex Ltd | Real estate | 2026 |
| Stonecorp Co Limited | Financial services | 2025 |
| Stonegate Fencing Ltd | Wholesale & retail | 2025 |
| Stonehaven Advisors Limited | Professional & scientific | 2021 |
| Stormer Trading Ltd | Wholesale & retail | 2022 |
| Storrington Take Away Ltd | Hospitality | 2025 |
| Straight UP Technologies UK Limited | Information & communication | 2011 |
| Strategic Global Partnership Limited | Administrative & support | 2014 |
| Stratton House Leasing Limited | Professional & scientific | 1986 |
| Stratumi Consulting Limited | Wholesale & retail | 2025 |
| Streamline Cars Crawley Ltd | Transport & logistics | 2025 |
| Streets United Limited | Arts & recreation | 2009 |
| Streetwise Couriers Sussex Ltd | Transport & logistics | 2006 |
| Stribe Fitness Limited | Arts & recreation | 2015 |
| Structural Designworks Limited | Extraterritorial | 2016 |
| Strynix Limited | Manufacturing | 2025 |
| STS Media Limited | Information & communication | 2021 |
| STS Real Estate Ltd | Real estate | 2025 |
| Stsoe Investments Limited | Financial services | 2024 |
| Stuart James Leisure Limited | Information & communication | 2025 |
| Studio 13 Ltd | Other services | 2014 |
| Studio Ninety-Three Design & Renovations Ltd | Construction | 2023 |
| Studio Serene Limited | Professional & scientific | 2025 |
| Study Connect UK Ltd | Education | 2013 |
| Study Source Consultant Ltd | Education | 2025 |
| STV Support Ltd | Financial services | 2025 |
| Stylso Sports Ltd | Wholesale & retail | 2020 |
| Sub-Cool FM Limited | Administrative & support | 2015 |
| Sub-Cool FM Prop Limited | Real estate | 2020 |