| Stock Mood Ltd | Wholesale & retail | 2026 |
| Stockd Ltd | Information & communication | 2025 |
| Stod Limited | Information & communication | 2019 |
| Stoke Court Management Company Limited | Real estate | 2005 |
| Stomp Productions Ltd | Arts & recreation | 2005 |
| Stone & Wood Events Ltd | Wholesale & retail | 2026 |
| Stone Signs Limited | Administrative & support | 2025 |
| Stonehouse Farm Developments Limited | Real estate | 1997 |
| Stoopy Ltd | Health & social care | 2024 |
| Stopp Productions Limited | Information & communication | 2018 |
| Storage Bros Limited | Administrative & support | 2024 |
| Storiverse Ltd | Information & communication | 2021 |
| Storm Basketball Club Ltd | Education | 2021 |
| Stormnet Solutions Ltd | Information & communication | 2025 |
| Storrington Auto Repairs Limited | Wholesale & retail | 2002 |
| Storrington Squash Club Limited | Arts & recreation | 2010 |
| Story Designs Limited | Professional & scientific | 2013 |
| Storyscreen Ltd | Information & communication | 2021 |
| Stott Craft Design & Build Limited | Extraterritorial | 2001 |
| Stowmere Ltd | Administrative & support | 2024 |
| Stoy 2015 LLP | | 2015 |
| Strachan Holdings Sussex Ltd | Financial services | 2026 |
| Straight 10 Management Limited | Professional & scientific | 2015 |
| Straightline Carpentry Ltd | Construction | 2022 |
| Strand Pet Supplies Limited | Wholesale & retail | 2019 |
| Strangelove Investments Limited | Real estate | 2015 |
| Strangelove Limited | Administrative & support | 2012 |
| Stranger Media Ltd | Arts & recreation | 2002 |
| Strata-Brocke Limited | Construction | 2015 |
| Stratacore Drilling Services Ltd | Construction | 2025 |
| Strategy Advice Services Limited | Professional & scientific | 2020 |
| Stratesg Ltd | Administrative & support | 2026 |
| Stratford Court Management Company Limited | Households | 1997 |
| Stratovate Ltd | Administrative & support | 2015 |
| Stratus Student Management Limited | Real estate | 2025 |
| Straw HAT Productions Ltd | Information & communication | 2023 |
| Strawberry Marquees Limited | Administrative & support | 2021 |
| Stray K Limited | Professional & scientific | 2015 |
| Street Construction Limited | Construction | 2003 |
| Strenson Brighton Ltd | Hospitality | 2018 |
| Strenson Investments Limited | Construction | 2011 |
| Strenson Leisure Limited | Hospitality | 2014 |
| Strenson West Sussex Ltd | Hospitality | 2018 |
| Stretch Hove Ltd | Hospitality | 2026 |
| Stride Social Ltd | Professional & scientific | 2022 |
| Strogden Limited | Financial services | 2015 |
| Strong Journal Ltd | Information & communication | 2025 |
| Stroudley Road Management Company Limited | Households | 2006 |
| Structural Repairs Direct Limited | Construction | 2024 |
| STS (Sussex) Ltd | Professional & scientific | 2026 |
| Stuart Pendleton Consulting Ltd | Financial services | 2020 |
| Stuart Shepherd Properties Limited | Real estate | 2013 |
| Studio 15 Architects Limited | Professional & scientific | 2015 |
| Studio Consultancy Ltd | Information & communication | 2026 |
| Studio Crook Limited | Information & communication | 2021 |
| Studio Ellis Ltd | Wholesale & retail | 2020 |
| Studio Gang Limited | Administrative & support | 2025 |
| Studio Reid Limited | Professional & scientific | 2024 |
| Studio Sculpture Limited | Arts & recreation | 2025 |
| Studio Sculpture Worthing Limited | Arts & recreation | 2026 |
| Studio YG Ltd | Wholesale & retail | 2023 |
| Studious Fish Limited | Professional & scientific | 2023 |
| Studland Property Holdings Ltd | Real estate | 2018 |
| Stuggy Mania Limited | Other services | 2015 |
| Stukeley Park (Management) Limited | Households | 1995 |
| Stupendium Holdings Limited | Financial services | 2025 |
| Stupendium Softworks Limited | Information & communication | 2025 |
| Sturt 1 Ltd | Manufacturing | 2022 |
| Stuts Live Ltd | Information & communication | 2024 |
| Stylissima Ltd | Administrative & support | 2020 |
| Subway EPS Limited | Manufacturing | 2009 |
| Suddenly, Frogs Ltd | Information & communication | 2016 |
| Sugarloaf Inns Limited | Hospitality | 2013 |
| Sugrue Hutson Vineyards Limited | Agriculture & fishing | 2022 |
| Sugrue South Downs Group Limited | Financial services | 2024 |
| Sugrue South Downs Limited | Agriculture & fishing | 2013 |
| Summa Tech Limited | Information & communication | 2020 |
| Summer Lightning Limited | Other services | 2019 |
| Summit Consult Limited | Professional & scientific | 2005 |
| Summit Mechanical Ltd | Construction | 2025 |
| Sumners Ponds Limited | Agriculture & fishing | 2004 |
| Sunbeam Property Limited | Extraterritorial | 2012 |
| Sunbeam Property Subsidiary Limited | Real estate | 2012 |
| Sunken Knave Limited | Manufacturing | 2023 |
| Sunny Organics Ltd | Agriculture & fishing | 2025 |
| Sunnyhill Developments Limited | Extraterritorial | 2014 |
| Sunrise Entertainment Ltd | Information & communication | 2021 |
| Sunstore Properties Limited | Real estate | 2015 |
| Sunstoresolar Ltd | Manufacturing | 2011 |
| Supa Talent Ltd | Education | 2018 |
| Super GT Limited | Information & communication | 2020 |
| Super Strange Studios Ltd | Information & communication | 2016 |
| Super Stuff Ltd | Arts & recreation | 2018 |
| Superfractory Limited | Wholesale & retail | 2026 |
| Superior Carpet Care Ltd | Construction | 2021 |
| Superliminal Limited | Information & communication | 2025 |
| Superstars Guitar Academy Ltd | Education | 2023 |
| Superstars Media Limited | Financial services | 2026 |
| Supply Chain Insights Ltd | Information & communication | 2019 |
| Support CFO Limited | Professional & scientific | 2024 |