| Solune Creation Limited | Wholesale & retail | 2026 |
| Solve 4YOU Services Ltd | Other services | 2022 |
| Sonal Health Limited | Health & social care | 2022 |
| Sonata Europe Limited | Information & communication | 2006 |
| Sonhe Ltd | Professional & scientific | 2019 |
| Sonnys Team Limited | Health & social care | 2018 |
| Soul City Limited | Information & communication | 2025 |
| Soulful Radiance Ltd | Health & social care | 2025 |
| Souraya London Limited | Wholesale & retail | 2019 |
| Southern Classics (92) EOT Ltd | Professional & scientific | 2023 |
| Southern Classics (92) Limited | Wholesale & retail | 1992 |
| Southwark Handyman Services Ltd | Construction | 2016 |
| SP Accounting and Bookkeeping Ltd | Professional & scientific | 2016 |
| SP Javid Limited | Real estate | 2025 |
| SP Legacy Ltd | Wholesale & retail | 2023 |
| Space a Construction Ltd | Construction | 2023 |
| Space White Limited | Professional & scientific | 2019 |
| Spacex Autos Ltd | Wholesale & retail | 2024 |
| Sparkcore Ltd | Wholesale & retail | 2023 |
| Sparkout Solutions Ltd | Professional & scientific | 2024 |
| Sparky Properties Limited | Real estate | 2019 |
| SPE Global Solutions Ltd | Wholesale & retail | 2020 |
| Speak OUT in Hounslow | Other services | 2001 |
| Speed-Tech (UK) Limited | Transport & logistics | 2004 |
| Speedway Trucking Limited | Transport & logistics | 2007 |
| Speroy Consultancy Ltd | Professional & scientific | 2025 |
| Sphinx Refurbishment Ltd | Construction | 2016 |
| Spice Fusion Food Limited | Hospitality | 2025 |
| Spike LAB Ltd | Information & communication | 2021 |
| Spindle Magazine Ltd | Information & communication | 2010 |
| Spintu Ltd | Construction | 2017 |
| Spire Collective Limited | Professional & scientific | 2025 |
| Spiritbe Technology Ltd | Information & communication | 2025 |
| Spiritual Root Limited | Health & social care | 2025 |
| Spond Ltd | Information & communication | 2021 |
| Sport Blasts Ltd | Financial services | 2023 |
| Spotless Express Ltd | Transport & logistics | 2024 |
| Springboard Applications Limited | Administrative & support | 2016 |
| Springett Place Ltd | Information & communication | 2022 |
| Sprout Real Estate Limited | Real estate | 2025 |
| SR Premium Technologies Limited | Construction | 2018 |
| SRE Staines Limited | Construction | 2018 |
| Srinivasa Foods Limited | Hospitality | 2016 |
| SS Ealing Ltd | Real estate | 2019 |
| SS GUY Limited | Professional & scientific | 2021 |
| SSB Enterprises Limited | Other services | 2016 |
| SSG Build Ltd | Construction | 2025 |
| SSM Consulting Limited | Professional & scientific | 2018 |
| SSR System Ltd | Information & communication | 2016 |
| ST Etienne Resources Limited | Administrative & support | 2015 |
| ST Margaret Estates Ltd | Real estate | 2020 |
| ST. George Crown Elite Chauffeurs London Ltd | Transport & logistics | 2026 |
| ST8 Studio Limited | Professional & scientific | 2022 |
| Stannic Stones Ltd | Construction | 2024 |
| Stanton Advisory Limited | Professional & scientific | 2025 |
| Star and 7SKY House Ltd | Hospitality | 2026 |
| Star Zeta Limited | Real estate | 2023 |
| Starck Uberoi Wealth Ltd. | Financial services | 2018 |
| Starfelia Ltd | Wholesale & retail | 2019 |
| Stargate TW8 Ltd | Financial services | 2024 |
| Starling Holdings Limited | Financial services | 2024 |
| Start an American Company.Com Ltd | Extraterritorial | 2012 |
| Start My Business Ltd | Professional & scientific | 2019 |
| Starwerks Limited | Wholesale & retail | 2019 |
| Stash Group Ltd | Wholesale & retail | 2026 |
| Station Parade House Limited | Construction | 2023 |
| Station Road Developments (Cambridge) Limited | Construction | 2005 |
| Stay Comfortable Ltd | Households | 2024 |
| Staywelcome Ltd | Real estate | 2021 |
| Staywhenever Ltd | Real estate | 2019 |
| Steak Inc. Holdings Limited | Wholesale & retail | 2026 |
| Stefsportsphysio Limited | Health & social care | 2023 |
| Sterling Merchant Group Ltd | Wholesale & retail | 2025 |
| Sterling Property Investment Group (UK) Ltd | Real estate | 2021 |
| Sterling-Chapeltown Limited | Professional & scientific | 1963 |
| Steven D Baker Engineering Services Limited | Professional & scientific | 2008 |
| Sticky Faces Ltd | Health & social care | 2018 |
| Sting Sports UK Limited | Wholesale & retail | 2017 |
| Stixo Ltd | Wholesale & retail | 2022 |
| Stoke Poges Estates Limited | Construction | 2001 |
| Stonebrook Motors Ltd | Wholesale & retail | 2011 |
| Stonekast Ltd | Wholesale & retail | 2011 |
| Stonemore Property Holdings Limited | Real estate | 2023 |
| Stoneville (UK) Limited | Construction | 2002 |
| Storevolution Ltd | Transport & logistics | 2018 |
| Strato Enterprises Ltd | Extraterritorial | 2019 |
| Strength Excellence Limited | Arts & recreation | 2018 |
| Stretton Care Limited | Health & social care | 2004 |
| Strictly Accounting Ltd | Professional & scientific | 2021 |
| Strong Point Investments Ltd | Real estate | 2022 |
| Structural United Ltd | Professional & scientific | 2019 |
| STS Global Ltd. | Wholesale & retail | 2007 |
| Studio 9 Barbershop Ltd | Other services | 2026 |
| Studio C&V Ltd | Wholesale & retail | 2025 |
| Studio Como Ltd | Professional & scientific | 2026 |
| Studio Gdlhm Ltd | Professional & scientific | 2020 |
| Studio Silue Ltd | Wholesale & retail | 2024 |
| Studio Zeta Limited | Manufacturing | 2003 |
| Styxtech Ltd | Information & communication | 2020 |
| Subliminal Infrastructure Limited | Information & communication | 2016 |