| Solvion Ltd | Wholesale & retail | 2024 |
| Soma Renovo Group Ltd | Real estate | 2025 |
| Some Like IT Hot Limited | Extraterritorial | 2004 |
| Somebody Lied Inc Ltd | Education | 2018 |
| Someluck Limited | Real estate | 2013 |
| Something Special Cleans Ltd | Administrative & support | 2026 |
| Sona Chandi Empire Ltd | Other services | 2020 |
| Sonali Transport Ltd | Administrative & support | 2017 |
| Sone Marketing Ltd | Professional & scientific | 2024 |
| Songa Global Limited | Financial services | 2024 |
| Sonia's Grill Ltd | Hospitality | 2018 |
| Sonney Bentley Ltd | Administrative & support | 2024 |
| Sonology Limited | Health & social care | 2025 |
| Sonrisa Care Limited | Administrative & support | 2013 |
| Sonya Stephens Consulting Limited | Professional & scientific | 2015 |
| Soori Ltd | Information & communication | 2026 |
| Sophicel Ltd | Administrative & support | 2022 |
| Sophiera Limited | Real estate | 2019 |
| SOS Construction and Building Services Ltd | Construction | 2025 |
| Soulbridge Ventures Ltd | Health & social care | 2025 |
| Sound and Soul Limited | Wholesale & retail | 2025 |
| Sound Financial Advice Limited | Administrative & support | 2008 |
| Sound Property Management Limited | Financial services | 2017 |
| Soundbox Group Ltd | Manufacturing | 2011 |
| Soundbox Holdings Ltd | Information & communication | 2024 |
| Soundbox Music Ltd | Information & communication | 2013 |
| Soundbox Publishing Ltd | Information & communication | 2013 |
| Soundbox Studios Ltd | Information & communication | 2013 |
| Soundward Limited | Real estate | 1981 |
| Soupyakult Ltd | Hospitality | 2020 |
| Sourceco Ltd | Professional & scientific | 2001 |
| South East Construction Training Ltd | Education | 2023 |
| South East Notary Public Limited | Professional & scientific | 2022 |
| South London Builders Ltd | Construction | 2022 |
| South London CVS Partnership | Other services | 2007 |
| South Studios Ltd | Other services | 2025 |
| South Thames Scaffolding Limited | Construction | 2006 |
| Southern Construction Ltd | Construction | 2025 |
| Southern ECS Ltd | Construction | 2025 |
| Southside UK Property Ltd | Real estate | 2018 |
| Southstone Financial Services Ltd | Financial services | 2026 |
| Sovereign Homes UK Limited | Administrative & support | 2018 |
| SP Building Developers Limited | Construction | 2018 |
| SP Consultancy Ltd | Construction | 2021 |
| SP Develop & Build Ltd | Construction | 2025 |
| SP Theatre Ltd | Administrative & support | 2021 |
| Spaceplan Projects Limited | Arts & recreation | 1988 |
| Spacerise Lofts Ltd | Construction | 2024 |
| Spaghetti Tree Restaurants Limited | Hospitality | 2021 |
| Spagtree Limited | Hospitality | 2024 |
| Sparjun Ltd | Real estate | 2022 |
| Sparkle Home London Ltd | Administrative & support | 2023 |
| Sparkly Media Ltd | Other services | 2025 |
| Sparkole Ltd | Manufacturing | 2020 |
| Sparkplugelectric Ltd | Construction | 2024 |
| Sparks Electrical and Solar Ltd | Construction | 2023 |
| Sparksys Limited | Information & communication | 2023 |
| Sparky Pictures Ltd | Information & communication | 2018 |
| Sparrow Building Ltd | Construction | 2014 |
| Spartan Heating Ltd | Construction | 2011 |
| Spatialised Limited | Professional & scientific | 2013 |
| Spears Care Limited | Extraterritorial | 2020 |
| Specctrum Limited | Information & communication | 2020 |
| Special First Steps Ltd | Education | 2024 |
| Specialty Risks Limited | Financial services | 2008 |
| Specialty Solutions Limited | Financial services | 2017 |
| Specific Projects Ltd | Construction | 2006 |
| Spectrum Accountants Ltd | Professional & scientific | 2020 |
| Speedy Concrete Pumping Services Ltd | Construction | 2020 |
| Speedyl Limited | Transport & logistics | 2024 |
| Speedys Scaffolding Limited | Construction | 2010 |
| Spen Investments Ltd | Construction | 2020 |
| SPG Consulting Services Ltd | Information & communication | 2023 |
| SPG London Properties Ltd | Real estate | 2023 |
| Spiceylon Ltd | Hospitality | 2022 |
| Spiff & Spruce Ltd | Administrative & support | 2022 |
| Spiff + Spruce Commercial Cleaning Ltd | Administrative & support | 2023 |
| Spinnbass Limited | Arts & recreation | 2021 |
| Spirit Corporation Ltd | Real estate | 2011 |
| Splash N Dash Dogs Ltd | Other services | 2025 |
| Sponte SUA Ltd | Arts & recreation | 2014 |
| Spotless Solution Services Ltd | Administrative & support | 2026 |
| SPR Public Relations Limited | Professional & scientific | 2022 |
| Spree London Limited | Wholesale & retail | 2019 |
| Spring Court (Ewell) Management Company Limited | Households | 1967 |
| Spring Klean Limited | Other services | 2003 |
| Spring Lakes Campsite and Fisheries Limited | Hospitality | 2021 |
| Springcloud Solutions Limited | Information & communication | 2019 |
| Sprint Waste Clearance Ltd | Water & waste | 2019 |
| SQ Building Services Ltd | Construction | 2024 |
| Squat Success Limited | Professional & scientific | 2025 |
| Sqware Ltd | Wholesale & retail | 2022 |
| SR Physio London Limited | Health & social care | 2025 |
| SR Property Management Ltd | Real estate | 2006 |
| Sram Engineering Ltd | Construction | 2013 |
| Sree Infotech Ltd | Information & communication | 2012 |
| Sree K Limited | Financial services | 2024 |
| Sree K Properties Limited | Real estate | 2024 |
| Srftech Engineering Services and Consultancy Ltd | Information & communication | 2019 |
| SRI Lakshmi Ganesha Limited | Real estate | 2024 |