| Scentual Touch Ltd | Wholesale & retail | 2018 |
| SCF Education Ltd | Education | 2024 |
| School Mews (Felpham) Management Limited | Households | 1989 |
| School Walls Ltd | Education | 2025 |
| Scoffa Ltd | Hospitality | 2023 |
| Scopegrid Ltd | Professional & scientific | 2025 |
| Scott Jenkins Water Softeners Limited | Construction | 2017 |
| Scumrun Limited | Administrative & support | 2001 |
| SD Crockford Holdings Ltd | Financial services | 2026 |
| SDG Care 24/7 Limited | Health & social care | 2022 |
| SDS Carpentry Ltd | Manufacturing | 2019 |
| Sea View Pizza Ltd | Hospitality | 2025 |
| Seaco Screenprint & Signs Limited | Manufacturing | 1995 |
| Seagry Care Limited | Health & social care | 2014 |
| Seal Developments Limited | Construction | 2019 |
| Sealant Expert Ltd | Construction | 2020 |
| Seaview Advisors Limited | Professional & scientific | 2020 |
| Sect Run Limited | Wholesale & retail | 2026 |
| SEE Lovi Ltd | Hospitality | 2023 |
| Seedley Mini Market Ltd | Wholesale & retail | 2018 |
| Select Builds Sussex Limited | Construction | 2016 |
| Sell & Repair Ltd | Wholesale & retail | 2019 |
| Sentinel Equipment Services Ltd | Manufacturing | 2025 |
| Serene Property Solutions Ltd | Real estate | 2019 |
| Serious Scran Ltd | Hospitality | 2026 |
| Serotonin Impex UK Limited | Professional & scientific | 2023 |
| Sethi Residential Ltd | Real estate | 2025 |
| Seven Hills Productions Limited | Information & communication | 2014 |
| Sewing by Barbara Ltd | Manufacturing | 2024 |
| SG Tanks Limited | Construction | 2014 |
| Shadyclay Limited | Construction | 1997 |
| Shakespeare Property Management Limited | Households | 2012 |
| Shakespeare's Landscapes Limited | Administrative & support | 2012 |
| SHC Corporate Consulting Limited | Professional & scientific | 2015 |
| Sheldon Properties (Surrey) Limited | Real estate | 1984 |
| Sheridan Wolf Limited | Wholesale & retail | 2004 |
| Sheytrans Ltd | Transport & logistics | 2021 |
| Ship and Castle (Pompey) Limited | Hospitality | 2026 |
| Shipease Ltd | Wholesale & retail | 2023 |
| Shoeshack Limited | Financial services | 2010 |
| Shogun Solutions Ltd | Administrative & support | 2024 |
| Shore & Family Property Management Limited | Households | 2020 |
| Shore Analytics UK Ltd | Information & communication | 2024 |
| Shore Financial Services Ltd | Financial services | 2004 |
| Shorehome Ltd | Real estate | 2023 |
| Shoreline Financial Planning Limited | Financial services | 2020 |
| Shorts Window Cleaning Ltd | Administrative & support | 2016 |
| Show Weight Solutions Limited | Professional & scientific | 2025 |
| Shripney Road 1973 Limited | Extraterritorial | 2014 |
| Sibel (UK) Ltd | Wholesale & retail | 2012 |
| Sicomtbproducts.Com Ltd | Wholesale & retail | 2019 |
| Sideyard Limited | Transport & logistics | 2025 |
| Sidlesham Body Shop Limited | Wholesale & retail | 2009 |
| Sidney House Development Services Ltd | Professional & scientific | 2012 |
| Siga Creative FX Limited | Manufacturing | 2011 |
| Signquick Limited | Manufacturing | 1995 |
| Signs 4 Golf Ltd | Arts & recreation | 2021 |
| Sillbluff Limited | Professional & scientific | 1981 |
| Silver Lime Holdings Limited | Financial services | 2025 |
| Silverthorne Capital Ltd | Real estate | 2025 |
| Simple Cremation Service Ltd | Other services | 2026 |
| Simply Courteous Limited | Other services | 1997 |
| Sinclair Gardens Investments (Kensington) Limited | Construction | 1963 |
| Singletons Farm Management Company Limited | Households | 2020 |
| Sink Golf Ltd | Manufacturing | 2018 |
| SIS Beauty & Cosmetics Ltd | Other services | 2022 |
| SIX the Steyne Limited | Real estate | 2019 |
| SJ Scaffolding (Sussex) Ltd | Construction | 2025 |
| SJD Supplies Limited | Wholesale & retail | 2000 |
| SJW Catering Consultancy Ltd | Hospitality | 2017 |
| Skad Property Enterprise Ltd | Real estate | 2024 |
| Skilldeed Limited | Manufacturing | 1987 |
| Skinner Landscapes Limited | Administrative & support | 2024 |
| Skulking Loafers Limited | Arts & recreation | 2024 |
| Sky 99 UK Ltd | Health & social care | 2020 |
| SKY99 Holdings Ltd | Financial services | 2026 |
| Skydot Drones Limited | Arts & recreation | 2025 |
| Skyline Scaffold Solutions Limited | Construction | 2018 |
| SL Electrical Ltd | Construction | 2017 |
| SLM Renovations Limited | Construction | 2022 |
| SLP Decorations Limited | Construction | 2009 |
| SLR Swift Services Ltd | Administrative & support | 2023 |
| Smart Kitchens Limited | Manufacturing | 2005 |
| Smart Search Solutions Ltd | Information & communication | 2025 |
| Smart Shop Expert Ltd | Wholesale & retail | 2022 |
| Smart Way Accounting Services Ltd | Professional & scientific | 2015 |
| Smarter Way Group Ltd | Financial services | 2022 |
| Smash Burger Kitchen Limited | Hospitality | 2025 |
| SMB Wealth Management Limited | Financial services | 2007 |
| SMC Southern Contractors Limited | Construction | 2023 |
| Smile FIX Ltd | Health & social care | 2018 |
| Smile Servicing & Repairs Limited | Wholesale & retail | 2009 |
| Smith & Langton Limited | Construction | 2000 |
| Smith and Timber Ltd | Construction | 2024 |
| Smith Commercial Services Limited | Professional & scientific | 2024 |
| Smithco Limited | Construction | 2009 |
| SML Decorators Ltd | Construction | 2020 |
| Snackology Ltd | Manufacturing | 2026 |
| Snell Bros Surfboards LLP | | 2021 |
| Snook's Gift Boutique Ltd | Wholesale & retail | 2019 |