| Snowdrop Professional Services Limited | Professional & scientific | 2008 |
| Snowpine Limited | Professional & scientific | 1981 |
| Snug BUD UK Ltd | Administrative & support | 2020 |
| SO Lovely Hair and Beauty Limited | Other services | 2018 |
| Society of British and Argentine Lawyers Limited | Administrative & support | 2019 |
| Sofia 23 Limited | Hospitality | 2025 |
| Sofia Market Ltd | Wholesale & retail | 2022 |
| Soilwater Ltd | Wholesale & retail | 2018 |
| Solo Bespoke Jewellery Ltd | Manufacturing | 2003 |
| Solutions Roofing & Construction Limited | Construction | 2014 |
| Some Voices Ltd | Arts & recreation | 2015 |
| Sophie's Kitchen Sussex Ltd | Hospitality | 2023 |
| Soul Kitchen & Bar Limited | Hospitality | 2024 |
| Source Fire Risk Management Ltd | Information & communication | 2012 |
| Source FRM Ltd | Public administration | 2025 |
| Sourdough Sisters Ltd | Hospitality | 2026 |
| South Central Independent Roofing Training Group | Professional & scientific | 2007 |
| South Coast Boudoir Ltd | Hospitality | 2024 |
| South Coast Composites Limited | Manufacturing | 2012 |
| South Coast DPF Cleaning Services Limited | Wholesale & retail | 2022 |
| South Coast Fire and Electrical Ltd | Construction | 2024 |
| South Coast Fire Testing Ltd | Administrative & support | 2019 |
| South Coast Pizza and Chicken Ltd | Hospitality | 2026 |
| South Coast Property Consultants Limited | Construction | 2009 |
| South Coast Property Management Limited | Real estate | 2001 |
| South Coast Roof Training Ltd | Administrative & support | 2005 |
| South Coast Sports Coaching Ltd | Education | 2014 |
| South Coast Sports Coastal CIC | Education | 2023 |
| South Downs Decorators Ltd | Construction | 2024 |
| South Downs Rise Limited | Real estate | 2015 |
| Southcoast Airconditioning Limited | Extraterritorial | 2000 |
| Southcoast Building Services Ltd | Construction | 2016 |
| Southcoast Heating Ltd | Construction | 2025 |
| Southcoast Sweeps Ltd | Administrative & support | 2022 |
| Southdowns Plumbing and Heating Engineers Ltd | Construction | 2014 |
| Southern Automation Specialists Ltd | Manufacturing | 2021 |
| Southern Autos Limited | Wholesale & retail | 2025 |
| Southern Clean Exteriors Limited | Administrative & support | 2018 |
| Southern Cross Garage Ltd | Manufacturing | 2021 |
| Southern GAS Turbines Limited | Manufacturing | 1984 |
| Southern JAR Company Ltd | Wholesale & retail | 2023 |
| Southern Rental Properties Ltd | Real estate | 2022 |
| Southern Scaffold UK Ltd | Construction | 2026 |
| Southern VSR Ltd | Manufacturing | 2024 |
| Southernbrook Estate Management Ltd | Real estate | 2019 |
| Southgate International Limited | Wholesale & retail | 2006 |
| Southlands Court Limited | Households | 1963 |
| Southwood (Kent) Limited | Real estate | 2018 |
| Souzana Rizgkala Therapies CIC | Health & social care | 2024 |
| Sovereignty Ventures Limited | Wholesale & retail | 2024 |
| SP Paving Solutions Limited | Construction | 2026 |
| SP Plumbing (Sussex) Ltd | Construction | 2025 |
| Spaform Limited | Other services | 2018 |
| Sparkhive Tech Ltd | Information & communication | 2025 |
| Sparkle & Shine Valeting Limited | Other services | 2025 |
| Spearium Properties Ltd | Real estate | 2026 |
| Spectrum CFA Ltd | Professional & scientific | 2025 |
| Spice Logic Ltd | Information & communication | 2025 |
| Spicer Property Services Ltd | Construction | 2023 |
| Spike White Lighting Ltd | Information & communication | 2009 |
| Splash Hounds Ltd | Wholesale & retail | 2025 |
| SPM Equity Ltd | Financial services | 2008 |
| Spoontech Ltd | Professional & scientific | 2024 |
| Sportxplore Ltd | Education | 2024 |
| SPT Construction Consultancy Ltd | Professional & scientific | 2019 |
| SRL Power Solutions Ltd | Professional & scientific | 2025 |
| SRM Brickwork Ltd | Construction | 2012 |
| Ss&G Retail Ltd | Wholesale & retail | 2024 |
| Ssbs Associates Limited | Professional & scientific | 2019 |
| SSM C Rentals Ltd | Real estate | 2024 |
| ST Botolphs Lodge (Worthing) Limited | Professional & scientific | 2007 |
| ST Georges Gardens Residential Management Ltd | Real estate | 2024 |
| ST. Andrews Residents Limited | Hospitality | 2001 |
| Stables Square Management Company Limited | Real estate | 2024 |
| Stacey Love Property Limited | Real estate | 2024 |
| Stack House Residents (Oxted) Limited | Households | 1978 |
| Stamforddental Ltd | Health & social care | 2022 |
| Standive Limited | Wholesale & retail | 1993 |
| Stanton Miller Consultancy Limited | Professional & scientific | 2022 |
| Star BBQ Ltd | Hospitality | 2021 |
| Stardam Productions Ltd | Arts & recreation | 2014 |
| Starfish Charter Limited | Agriculture & fishing | 2019 |
| Starling Autocenter Ltd | Wholesale & retail | 2025 |
| Station Garden Limited | Hospitality | 2019 |
| Station Road Bakery&Cafe Ltd | Manufacturing | 2023 |
| Staunch Construction Services Ltd | Construction | 2026 |
| Staunton Funeral Services Ltd | Other services | 2018 |
| Stavecroft Limited | Wholesale & retail | 2002 |
| Staygrip Limited | Manufacturing | 2005 |
| Steam X Ltd | Manufacturing | 2017 |
| Steden Construction Ltd | Construction | 2025 |
| Steel & Strike Ltd | Arts & recreation | 2026 |
| Stef S Cleaning Services Limited | Administrative & support | 2025 |
| Stencil & Forge Ltd | Manufacturing | 2025 |
| Stephen Wall Limited | Administrative & support | 2012 |
| Steve Batchelor Limited | Information & communication | 2008 |
| Steve Hills Maintenance Limited | Administrative & support | 2008 |
| Steve Hodgkins Ltd | Construction | 2021 |
| Stevens Contracting Ltd | Construction | 2017 |
| Stevens Hutchison & Co. Ltd | Construction | 2025 |