| Smisfatuk Limited | Health & social care | 2021 |
| Sniffair Limited | Administrative & support | 2010 |
| Social Graces Consultants Ltd | Health & social care | 2023 |
| Social Needia Ltd | Manufacturing | 2024 |
| Socro (London) Ltd | Information & communication | 2023 |
| Socro Limited | Information & communication | 2012 |
| SOE Compliance Ltd | Professional & scientific | 2016 |
| Softsol Limited | Information & communication | 1995 |
| Soie Veil Beauty Ltd | Wholesale & retail | 2026 |
| Solar Scale Ltd | Professional & scientific | 2020 |
| Solarcore Partners Ltd | Professional & scientific | 2026 |
| Solaris Energy Group Ltd | Construction | 2024 |
| Solle Projects Ltd | Construction | 2020 |
| Solo Partners Limited | Professional & scientific | 2024 |
| Solo Temple Limited | Construction | 2024 |
| Solvanta Limited | Information & communication | 2025 |
| Solve-X Ltd | Information & communication | 2021 |
| Somerset Road Limited | Households | 2023 |
| Sonic Blue Consulting Ltd | Professional & scientific | 2025 |
| Sonic Blue Tech Ltd | Information & communication | 2020 |
| Sophigma Limited | Professional & scientific | 2023 |
| Soriano Property Investments LLP | | 2012 |
| Sorrell Estate Management (Addington) Limited | Households | 1978 |
| Sorryn Ltd | Construction | 2024 |
| Soul Space Limited | Health & social care | 2003 |
| Soulutionbox (Southern) Ltd | Professional & scientific | 2025 |
| Soundwave Limited | Information & communication | 2010 |
| Source and Deliver Ltd | Wholesale & retail | 2025 |
| Sourced Components Limited | Manufacturing | 2009 |
| South Downs Clinic Ltd | Health & social care | 2011 |
| South East Open Source Solutions Limited | Information & communication | 2007 |
| South East Tennis (SET) Limited | Other services | 2023 |
| South West One Construction Ltd | Construction | 2023 |
| Southbrook (Crawley) Management Company Limited | Households | 1982 |
| Southern Glass and Glazing Repairs Limited | Construction | 2013 |
| Southmarsh Limited | Construction | 2016 |
| Southwark Diocesan Welcare | Health & social care | 2004 |
| SP Project Consultancy Limited | Professional & scientific | 2007 |
| Space 2 Store Limited | Professional & scientific | 2003 |
| Space to BE Coaching Limited | Other services | 2016 |
| Space to BE Consulting Ltd | Professional & scientific | 2022 |
| Space UK Homes Limited | Construction | 2024 |
| Space+Matter (Southern) Ltd | Construction | 2022 |
| Space+Matter Construction Ltd | Construction | 2022 |
| Space+Matter Design Ltd | Construction | 2022 |
| Space+Matter Ltd | Construction | 2015 |
| Sparber Consulting Ltd | Professional & scientific | 2023 |
| Sparkle Laundrette (Merstham) Ltd | Wholesale & retail | 2010 |
| Sparkle Redhill Carpet Cleaning & Upholstery Cleaning Ltd | Administrative & support | 2024 |
| Sparkles and Limes Ltd | Hospitality | 2014 |
| Sparksman Limited | Energy | 2017 |
| Speally Holdings Ltd | Financial services | 2024 |
| Speed Excel Transport Ltd | Transport & logistics | 2023 |
| Speedsells Ltd | Professional & scientific | 2026 |
| Sperrin Property Ltd | Real estate | 2025 |
| Sphere Custom Ltd | Professional & scientific | 2024 |
| Spica Healing Ltd | Health & social care | 2025 |
| Spike Consultancy Limited | Professional & scientific | 2014 |
| Spinfish Publishing Limited | Information & communication | 2015 |
| Spirit Brothers Ltd | Wholesale & retail | 2024 |
| Spirit Tree Ltd | Health & social care | 2023 |
| Sportch Limited | Arts & recreation | 2021 |
| Sporting Elite USA Ltd | Education | 2014 |
| Sportplan Limited | Education | 2000 |
| Sportplan UMS Limited | Arts & recreation | 2018 |
| Sports FUN N Fitness Limited | Arts & recreation | 2013 |
| Spotty Bear Ltd | Information & communication | 2013 |
| SPV Tooting Limited | Extraterritorial | 2025 |
| Square Daisy Ltd | Information & communication | 2011 |
| Squire Homes Ltd | Construction | 2019 |
| SR Mechanical Services Ltd | Construction | 2010 |
| Sreemangal Limited | Hospitality | 2025 |
| Sridhi Tech Ltd | Information & communication | 2022 |
| SRO Engineering Ltd | Transport & logistics | 2019 |
| SRV Infotech Limited | Information & communication | 2021 |
| SS Engineering Innovations Ltd | Professional & scientific | 2025 |
| SSD Holdings Limited | Financial services | 2021 |
| SSK 72PS Ltd | Financial services | 2023 |
| ST Julien Financial Planning Limited | Professional & scientific | 2022 |
| ST K&R Ltd | Health & social care | 2019 |
| ST. Annes Rise (5) Management Company Limited | Households | 1992 |
| ST. Georges (Crawley) Management Limited | Households | 1988 |
| ST. Marcus Fine Foods Limited | Hospitality | 1992 |
| ST. Mark & CEE Cleaning Services Limited | Administrative & support | 2025 |
| ST. Mark & CEE Healthcare Ltd | Health & social care | 2020 |
| ST. Mary's Walk Management Company Limited | Extraterritorial | 1996 |
| Stable Sharc Holdings Ltd | Real estate | 2022 |
| Stacey Clear Ltd | Real estate | 2023 |
| Stalwart Group UK Ltd | Wholesale & retail | 2023 |
| Stamford Project Management Ltd | Construction | 2013 |
| Stamp Developments Limited | Construction | 2014 |
| Stamp Holdings Limited | Professional & scientific | 1999 |
| Standford Consulting Limited | Professional & scientific | 2023 |
| Stanmore Investments Limited | Real estate | 1947 |
| Star Barber Redhill Limited | Other services | 2024 |
| Star Homes Property Limited | Households | 2025 |
| Starborough Road Developments Ltd | Construction | 2024 |
| Starkey Engineered Solutions Ltd | Professional & scientific | 2024 |
| Starline International Ltd | Public administration | 2024 |
| State Management Limited | Households | 1999 |