| SNT Properties LLP | | 2011 |
| SO What Labs Ltd | Information & communication | 2024 |
| Social Ascents Limited | Wholesale & retail | 2023 |
| Sofia Pharma UK Limited | Wholesale & retail | 2026 |
| Softech IT Consultancy Limited | Professional & scientific | 2022 |
| Soha Corporate Ltd | Construction | 2022 |
| Soho Bars & Clubs Ltd | Hospitality | 2019 |
| Soho Futures Holdings Limited | Financial services | 2015 |
| Soho Futures Limited | Financial services | 2015 |
| Sojen Limited | Information & communication | 2017 |
| Solar Roofing and Construction Ltd | Construction | 2022 |
| Solentura Energy Limited | Wholesale & retail | 2025 |
| Sonic Screenworks Ltd | Information & communication | 2010 |
| Sorlek Ltd | Information & communication | 2024 |
| SOS Holdings Ltd | Other services | 2009 |
| SOS Maintenance and Construction Limited | Extraterritorial | 2010 |
| SOS Payroll Limited | Administrative & support | 2017 |
| SOS Responsive Recruitment Limited | Extraterritorial | 2008 |
| SOS Safety Solutions Limited | Professional & scientific | 2020 |
| South East Heating Limited | Construction | 1988 |
| South East Mastclimbers Ltd | Construction | 2022 |
| South London Aesthetics Ltd | Other services | 2023 |
| South Park Removal Service Limited | Transport & logistics | 1952 |
| South Park Storage and Removals Limited | Transport & logistics | 2020 |
| Southern Oak Ltd | Wholesale & retail | 2023 |
| Southmere Limited | Professional & scientific | 2023 |
| SP Location Rental Limited | Administrative & support | 2012 |
| Space Brentwood Ltd | Arts & recreation | 2021 |
| Spaces Services Ltd | Administrative & support | 2022 |
| Sparkle Trading Limited | Manufacturing | 2001 |
| Sparrow Management Services Limited | Professional & scientific | 2009 |
| Speaktheworld Saturday School Ltd | Education | 2024 |
| Specialist Heavy Haulage Ltd | Transport & logistics | 2017 |
| Speke Property Holdings Limited | Transport & logistics | 2019 |
| Spica Windows Ltd | Construction | 2016 |
| Spice Cleaning Ltd | Administrative & support | 2024 |
| SPK Contracting Limited | Construction | 2003 |
| Sportnation Ltd | Information & communication | 2025 |
| Spot Textile Ltd | Wholesale & retail | 2012 |
| Spraytech Solutions Limited | Construction | 2015 |
| SR Business Consulting Ltd | Professional & scientific | 2018 |
| SRW Advisors Ltd | Professional & scientific | 2013 |
| SS Investments & Properties Ltd | Real estate | 2025 |
| SS6 Pubco Ltd | Hospitality | 2022 |
| ST Hilary Kings Lynn Management Company Limited | Households | 2016 |
| ST Laurence PRE School Limited | Education | 2018 |
| ST. James's Asset Management LLP | | 2005 |
| ST. James's Capital Partners Ltd | Administrative & support | 2012 |
| ST. Joseph's Catholic Club (Upminster) Limited | Hospitality | 2002 |
| Stadium Rider Training (Operations) Ltd | Wholesale & retail | 2014 |
| Stadium Rider Training Ltd | Education | 2014 |
| Staffxpert Ltd | Administrative & support | 2025 |
| Standage Business Ltd | Real estate | 1962 |
| Stanton Calverley Street Car Park Ltd | Real estate | 2026 |
| Stanton Capital Holdings Ltd | Financial services | 2026 |
| Stanton Services Ltd | Real estate | 2022 |
| Star Strategies Limited | Professional & scientific | 2024 |
| STAR1 Alliance Limited | Hospitality | 2025 |
| Starflo Ltd | Information & communication | 2025 |
| Stark Developments Ltd | Construction | 2022 |
| Stark Management Limited | Construction | 2018 |
| Stark Sourcing Solutions Ltd | Real estate | 2025 |
| Starstruck Autographs Limited | Wholesale & retail | 2015 |
| Steam and Gleam Limited | Administrative & support | 2025 |
| Stephen Hands Photography Limited | Professional & scientific | 2017 |
| Stma Property Services Ltd | Real estate | 2020 |
| Stoic Ascent Limited | Other services | 2022 |
| Storm Brooks Limited | Professional & scientific | 1998 |
| Storm Willow Limited | Health & social care | 2026 |
| Storybook Day Nurseries Limited | Education | 2014 |
| Strat House Ltd | Administrative & support | 2007 |
| Stretford Property Holdings Limited | Construction | 2014 |
| Stringz Events Ltd | Arts & recreation | 2026 |
| Student Rooms Limited | Real estate | 2020 |
| STUDENT2STUDENT Ltd | Education | 2019 |
| Sturge Interiors Ltd | Construction | 2015 |
| Submarine Production Ltd | Professional & scientific | 2021 |
| Successor Studios Limited | Wholesale & retail | 2025 |
| Sujas Limited | Professional & scientific | 2023 |
| Sullivan Consultancy Ltd | Professional & scientific | 2020 |
| Summermills Ltd | Construction | 2025 |
| Summit Financial Solutions (UK) Ltd | Financial services | 2014 |
| Summit Services London Ltd | Construction | 2025 |
| Sunny Horizon Property Ltd | Real estate | 2019 |
| Sunny Pumpkin Properties Limited | Real estate | 2023 |
| Sunny Pumpkin Services Limited | Real estate | 2023 |
| Sunny Rain Housekeepers Limited | Administrative & support | 2016 |
| Suns Power Ltd | Construction | 2024 |
| Sunset Consulting Limited | Information & communication | 2023 |
| Superior Shutters Limited | Construction | 2025 |
| Supply Chain Academy Holdings Limited | Education | 2011 |
| Supply Chain Academy Limited | Administrative & support | 1997 |
| Suzie Perry Events Ltd | Administrative & support | 2023 |
| Swap ANY Car Ltd | Other services | 2022 |
| Swider Properties Ltd | Real estate | 2024 |
| Swift Management Services Limited | Other services | 2019 |
| Swim-Back Legal Ltd | Information & communication | 2025 |
| SX Pest Control Ltd | Professional & scientific | 2018 |
| Synergistic Change Ltd | Information & communication | 2020 |
| Synertrade Limited | Wholesale & retail | 2008 |