| Snowling VA Services Ltd | Administrative & support | 2023 |
| Sober & Social Ltd | Other services | 2019 |
| Social Hour Limited | Wholesale & retail | 2024 |
| Solartec Services Ltd | Construction | 2022 |
| Solent Road Nominees Limited | Professional & scientific | 2000 |
| Solid Rock Property Ltd | Real estate | 2026 |
| Solitek Limited | Wholesale & retail | 1971 |
| Solvefit Ltd | Professional & scientific | 2021 |
| Somers Gate Residents Management Company Limited | Households | 2014 |
| Something for the Weekend Beauty Ltd | Other services | 2018 |
| Sonnet Marketing Limited | Administrative & support | 2013 |
| Sophos 777 Limited | Professional & scientific | 2025 |
| Soren Learning Solutions Limited | Education | 2009 |
| Soshi Ltd | Hospitality | 2024 |
| Sound of Family Ltd | Information & communication | 2019 |
| South Coast Dog Grooming Academy Ltd | Education | 2020 |
| South Coast GIS Limited | Professional & scientific | 2007 |
| South Coast Properties Management Ltd | Real estate | 2025 |
| South Coast Restaurants Holdings Limited | Financial services | 2025 |
| South Coast Restaurants Limited | Wholesale & retail | 1985 |
| South Coast Scenic Services Ltd | Information & communication | 2013 |
| South Coast Sheet Metal Ltd | Professional & scientific | 2022 |
| South Coast Tyres Ltd | Wholesale & retail | 2022 |
| South Coast Water Mains Ltd | Water & waste | 2026 |
| South Downs Clay Ltd | Wholesale & retail | 2025 |
| South Downs Electrical Services Ltd | Construction | 2012 |
| South Downs PUB Company Ltd | Hospitality | 2026 |
| South East Land Limited | Real estate | 2014 |
| South East Properties (Redhill) Limited | Construction | 1992 |
| South East Properties Limited | Construction | 1988 |
| South Eastern Planning Services Limited | Professional & scientific | 2005 |
| South Heritage Ltd | Real estate | 2021 |
| South Saxon Spirits Limited | Manufacturing | 2020 |
| South Terrace Limited | Real estate | 2019 |
| Southcoastsussex Ltd | Wholesale & retail | 2019 |
| Southern Building & Construction Ltd | Construction | 2002 |
| Southern Flight Limited | Manufacturing | 2006 |
| Southern Home Furnishings Limited | Wholesale & retail | 2013 |
| Southernebikes Ltd | Administrative & support | 2026 |
| Southsea Duck Co Ltd | Arts & recreation | 2019 |
| Sovereign Terrace Management Company Limited | Households | 1990 |
| SP Supply Ltd | Wholesale & retail | 2025 |
| Spare Parts Needed Ltd | Arts & recreation | 2020 |
| Spectrum Industrial Finishing Limited | | 1983 |
| Spencer Terrace Management Limited | Households | 2000 |
| Spencer Terrace Residents Ltd | Households | 2003 |
| Spga Investment Ltd | Real estate | 2017 |
| Spindrift Court (Climping) Management Company Limited | Households | 2002 |
| Spixon Limited | Administrative & support | 2022 |
| Splash and Tickle Limited | Administrative & support | 2008 |
| Sprayaway Cleaning Solutions Ltd | Administrative & support | 2025 |
| Spread Eagle Hotel (Midhurst) Limited(The) | Hospitality | 1949 |
| Springboard Media Limited | Information & communication | 2015 |
| Springbok Care Agency Ltd | Health & social care | 2011 |
| Springers Gardens & Landscapes Ltd | Water & waste | 2015 |
| Springtide LA Ltd | Administrative & support | 2026 |
| SPS Louvre Systems Limited | Construction | 2006 |
| Spud Buoys Ltd | Hospitality | 2026 |
| Squaddie Box CIC | Other services | 2025 |
| Square One Digital Ltd | Information & communication | 2017 |
| Squaredeal Upvc & Renewables Ltd | Construction | 2012 |
| SRW Asset Holdings Limited | Financial services | 2026 |
| SRW Trade Holdings Limited | Financial services | 2026 |
| ST Paul's On-The-Green (Haywards Heath) Management Company Limited | Households | 2007 |
| ST. Francis Veterinary Practice Limited | Professional & scientific | 2018 |
| ST. John's Road Westcliffe Management Limited | Households | 1977 |
| ST. Mary's Close Ltd | Households | 2014 |
| ST. Paulinus Management Limited | Households | 1972 |
| Stackedup Group Ltd | Hospitality | 2025 |
| Stanley Capital Investments Limited | Financial services | 2026 |
| Star Bright Private Limited | Other services | 2012 |
| Star Bright UK Limited | Transport & logistics | 2026 |
| Star Rocket & RAE Ltd | Financial services | 2021 |
| Starling View Management Company Limited | Real estate | 2021 |
| Starteam Global UK Limited | Manufacturing | 1997 |
| Station View (Billingshurst) Residents Management Limited | Households | 2013 |
| Stay Savvy Property Management Ltd | Real estate | 2024 |
| Steampacket Accommodation Ltd | Hospitality | 2017 |
| Steel Drains Limited | Water & waste | 2021 |
| Steels Plumbing & Heating Contractors Ltd | Construction | 2017 |
| Steelstar Ltd | Professional & scientific | 2010 |
| Sterck & Company Limited | Wholesale & retail | 2002 |
| Sterling Capital Homes Limited | Financial services | 2000 |
| Sterling FOX Ltd | Wholesale & retail | 2019 |
| Steve Pagett Ltd | Information & communication | 2018 |
| Steven Case Limited | Professional & scientific | 2012 |
| Stillwell Building Limited | Construction | 2006 |
| Stim's Consultancy Limited | Professional & scientific | 2007 |
| Stone by LEE Stone Ltd | Manufacturing | 2025 |
| Stourbridge Holdings (U.K.) Limited | Professional & scientific | 1965 |
| Strategic Lighting (Europe) Limited | Wholesale & retail | 2003 |
| Streamline Service Providers Limited | Administrative & support | 2024 |
| Street Food Revolution Ltd | Hospitality | 2023 |
| Strengthcourt Limited | Arts & recreation | 1981 |
| Striveas Ltd | Professional & scientific | 2025 |
| Strobilus Cafe Ltd | Hospitality | 2024 |
| Studio Finesse Limited | Administrative & support | 2017 |
| Suds 'N' ME Ltd | Wholesale & retail | 2022 |
| Sumbaba Limited | Information & communication | 2010 |
| Summerbrook Limited | Real estate | 2001 |