| Skysilver Optics Ltd | Health & social care | 2017 |
| Slater Signs Ltd | Manufacturing | 2019 |
| Slaters Engineering & Machining Services Ltd | Professional & scientific | 2025 |
| SLC Financial Ltd | Real estate | 2021 |
| Slgm Ltd | Financial services | 2014 |
| Slick Motorsport Ltd | Wholesale & retail | 2025 |
| SLK Plumbing & Heating Limited | Construction | 2025 |
| SM PVT Ltd | Wholesale & retail | 2024 |
| Sm&M Haulage Ltd | Transport & logistics | 2024 |
| Smart Cooling Ltd | Other services | 2016 |
| Smart Families Ltd | Education | 2020 |
| Smart Staff Ltd | Transport & logistics | 2009 |
| Smartpmtrade Ltd | Wholesale & retail | 2022 |
| SMASH06 Ltd | Wholesale & retail | 2025 |
| Smedley Homes Limited | Construction | 1985 |
| Smith & Gold Ltd | Manufacturing | 2021 |
| Smith Enforcement Ltd | Administrative & support | 2019 |
| Smith Malhotra Holdings Ltd | Professional & scientific | 2019 |
| Smith Malhotra Limited | Professional & scientific | 2001 |
| Smithelter LLP | | 2021 |
| Smithland Properties Limited | Extraterritorial | 2022 |
| Smiths Gold Ltd | Wholesale & retail | 2026 |
| Smithy’S Scaffolding Services Limited | Construction | 2022 |
| Smokey Rebel Ltd | Manufacturing | 2020 |
| Smooth Business Services Ltd | Other services | 1999 |
| Snax R US Ltd | Hospitality | 2024 |
| SNG Property Ltd | Real estate | 2021 |
| SNK Eyecare Ltd | Wholesale & retail | 2017 |
| SNL 978 Limited | Wholesale & retail | 2025 |
| Snle Consultancy Ltd | Professional & scientific | 2022 |
| Snop Driving Limited | Transport & logistics | 2017 |
| SO4K Limited | Other services | 2018 |
| Soap N Suds Ltd | Other services | 2005 |
| Soccer Elite FA (South East) Community Interest Company | Arts & recreation | 2010 |
| Soccer Elite FA Limited | Arts & recreation | 2006 |
| Soccer Elite Ltd | Arts & recreation | 2011 |
| Soft WAX Sounds Ltd | Information & communication | 2020 |
| Soixante Neuf Reclamation Limited | Wholesale & retail | 2025 |
| Sokaa Pharm Ltd | Health & social care | 2022 |
| Sol-Gel Materials & Applications Ltd | Professional & scientific | 2017 |
| Solaris Exterior Cleaning Limited | Administrative & support | 2021 |
| Solgelica Chemicals Ltd | Professional & scientific | 2022 |
| Solgelica Ltd | Professional & scientific | 2022 |
| Sollerskel Limited | Administrative & support | 2007 |
| Solomon Greens Ltd | Professional & scientific | 2026 |
| Solutions Audit Limited | Extraterritorial | 2008 |
| Song Signing Academy CIC | Education | 2023 |
| Sookjai Ltd | Other services | 2022 |
| Sopadel Ltd | Health & social care | 2019 |
| Sota Solutions Limited | Information & communication | 1989 |
| Soto Aesthetics Ltd | Health & social care | 2025 |
| Souffle to YOU Limited | Hospitality | 2001 |
| Sound & Vision Offers Limited | Professional & scientific | 2000 |
| Sound in the City Ltd | Administrative & support | 2012 |
| Sourcium Ltd | Wholesale & retail | 2025 |
| South East Land and Development Limited | Professional & scientific | 2022 |
| South East Medical Services Limited | Administrative & support | 2007 |
| South East Property Developments Ltd | Construction | 2005 |
| South East Property Solutions (Kent) Ltd | Construction | 2017 |
| South Eastern Alloy Coatings Ltd | Wholesale & retail | 2007 |
| Southern County Construction Limited | Wholesale & retail | 1986 |
| Southern Lettings Limited | Real estate | 2003 |
| Southern Microbiological Services Limited | Health & social care | 1989 |
| Sparks Hub Ltd | Construction | 2024 |
| Sparkshark Limited | Information & communication | 2026 |
| Spartak Ltd | Transport & logistics | 2015 |
| Spartan Clothing Limited | Administrative & support | 2012 |
| Spartan Safety Limited | Wholesale & retail | 1993 |
| Speccybean Limited | Wholesale & retail | 2020 |
| Spectral Development Ltd | Construction | 2019 |
| Spectrum Pro Limited | Administrative & support | 2025 |
| Speed Communications Limited | Extraterritorial | 1991 |
| Speedwork Limited | Real estate | 1976 |
| Spiller Health Ltd | Administrative & support | 2013 |
| Spiller Holdings Limited | Financial services | 2025 |
| Spinup Services Ltd | Information & communication | 2026 |
| Spitfire Building Services Kent Ltd | Construction | 2021 |
| SPN Multitrade Limited | Construction | 2017 |
| Sport Photo Gallery Limited | Manufacturing | 2000 |
| Sports Promotions Limited | Arts & recreation | 1963 |
| Springbank Contractors (South) Ltd | Construction | 2025 |
| Springbank Contractors Ltd | Construction | 2015 |
| Springwood Financial Ltd | Financial services | 2021 |
| SPW Property Limited | Real estate | 2022 |
| Spyder Creative Limited | Professional & scientific | 2010 |
| Square Elegance Limited | Administrative & support | 2018 |
| Squarehead Ltd | Information & communication | 2026 |
| Squirrel Marine Ltd | Agriculture & fishing | 2012 |
| Squirrel Woodland Rural Industries Ltd | Agriculture & fishing | 2011 |
| SR Glazing Kent Ltd | Construction | 2023 |
| SRB Electrical Services Limited | Construction | 2001 |
| Sreebhadra Limited | Health & social care | 2024 |
| SRJ Retail Hastings Ltd | Wholesale & retail | 2025 |
| SRM Project Engineering Ltd | Professional & scientific | 2018 |
| Srvy Ltd | Professional & scientific | 2023 |
| SSB FM Consultants Limited | Professional & scientific | 2025 |
| SSH Management Limited | Households | 1993 |
| ST Michael's Garage (Kent) Limited | Wholesale & retail | 2015 |
| ST Star Business Ltd | Wholesale & retail | 2026 |
| ST Thomas Place Apartments (Canterbury) Management Company Limited | Households | 2016 |