| Simplifiisolutions Limited | Information & communication | 2025 |
| Simply EAT Yoxall Limited | Hospitality | 2016 |
| Simply First Ltd | Wholesale & retail | 2019 |
| Simplymatched Boxing. Ltd | Arts & recreation | 2026 |
| Simulation FTS Limited | Public administration | 2009 |
| Simulation Maintenance Limited | Public administration | 2008 |
| Sinai Management Company Limited | Households | 2023 |
| Sinai Park House Trust | Education | 2016 |
| Sirius Tristar Ltd | Wholesale & retail | 2024 |
| Siterival Property Management Limited | Real estate | 1992 |
| Siwek Trans Ltd | Transport & logistics | 2018 |
| Sixpoint Services Limited | Construction | 2015 |
| SJ Abodes Limited | Households | 2025 |
| SJE Flooring Limited | Construction | 2021 |
| SK Pipework Ltd | Professional & scientific | 2021 |
| SK Prime Ltd | Wholesale & retail | 2021 |
| SK Steel Site Services Ltd | Construction | 2024 |
| SK Store (Burton) Limited | Wholesale & retail | 2018 |
| SKC Supper Clubs Ltd | Hospitality | 2023 |
| Sketch 5 Ltd | Information & communication | 2019 |
| SKG Impact Ltd | Professional & scientific | 2025 |
| Skinny Kitten Cafe and Bar Ltd | Hospitality | 2025 |
| Skipper Consultancy Ltd | Professional & scientific | 2021 |
| Skipper Property Limited | Real estate | 2019 |
| Skom Estates Ltd | Real estate | 2023 |
| Skom Group Ltd | Financial services | 2023 |
| SKW Consultants Limited | Information & communication | 2004 |
| Sky Aesthetics Ltd | Other services | 2025 |
| Sky Consorts Ltd | Information & communication | 2026 |
| Sky Creative Ltd | Information & communication | 2024 |
| Skydat Automotive & Nostalgia Ltd | Manufacturing | 2024 |
| Skytrax Aviation Limited | Professional & scientific | 1999 |
| Slade & Co UK Holdings Ltd | Wholesale & retail | 2025 |
| Slapsta Ltd | Manufacturing | 2019 |
| Slawomir Chrosciel Ltd | Transport & logistics | 2015 |
| Slees Beauty Limited | Other services | 2026 |
| Sliding Sash Supplies Limited | Wholesale & retail | 2010 |
| Slinky Limited | Professional & scientific | 2005 |
| SM Hazelwood Ltd | Real estate | 2025 |
| Small Feet Shoes Ltd | Administrative & support | 2017 |
| Small Universe Ltd | Wholesale & retail | 2017 |
| Smart Abode Systems Ltd | Wholesale & retail | 2019 |
| Smart and Perfect Solution Limited | Construction | 2024 |
| Smart HGV Solutions Ltd | Transport & logistics | 2025 |
| Smart in Book Keeping Services Ltd | Professional & scientific | 2020 |
| Smart Objects Limited | Information & communication | 2015 |
| Smartfits Installations Limited | Information & communication | 2009 |
| Smartfits Scaffolding Ltd | Construction | 2010 |
| SMARTWATCHES4U Ltd | Information & communication | 2014 |
| Smartway Traders Limited | Wholesale & retail | 2025 |
| SMC UK Property Management Ltd | Real estate | 2022 |
| SME Shopping Services Ltd | Wholesale & retail | 2023 |
| SMI Global Consulting Limited | Transport & logistics | 2025 |
| Smile Entertainment Limited | Arts & recreation | 2024 |
| Smith & Platts Homes Ltd | Real estate | 2024 |
| Smith & Platts Property Management Ltd | Real estate | 2020 |
| Smith, Burgess, and Smith Holdings Ltd | Hospitality | 2024 |
| Smithridge Franchising Limited | Administrative & support | 2024 |
| Smiths Avenue Management Company Limited | Households | 2022 |
| Smooth Laser and Skin Clinic Ltd | Other services | 2022 |
| Smurf Audio Limited | Information & communication | 2016 |
| Snap UP Direct Limited | Wholesale & retail | 2022 |
| Snugline Ltd | Wholesale & retail | 2026 |
| Sociatech Limited | Professional & scientific | 2010 |
| Socotec Building Control Limited | Professional & scientific | 1996 |
| Socotec UK Holding Limited | Administrative & support | 2017 |
| Sofintsys Limited | Information & communication | 2013 |
| SOI BEE Limited | Hospitality | 2026 |
| Soil Mechanics Limited | Extraterritorial | 1943 |
| Soku Burton Ltd | Wholesale & retail | 2026 |
| Soladell Limited | Real estate | 2021 |
| Solar Evolution (GBR) Ltd | Manufacturing | 2024 |
| Solarspec Ltd | Construction | 2023 |
| Solbeck Ltd | Professional & scientific | 2024 |
| Solewise Clinic Ltd | Health & social care | 2025 |
| Solidra Limited | Construction | 2026 |
| Solmar Villas Limited | Hospitality | 2010 |
| Solution Suppliers Limited | Information & communication | 2002 |
| Solux Hub Ltd | Wholesale & retail | 2025 |
| Sonder-Uk Ltd | Wholesale & retail | 2025 |
| Sophia Cura Ltd | Manufacturing | 2022 |
| SOSISKI67 Ltd | Wholesale & retail | 2026 |
| Sound Junkeyz Ltd | Arts & recreation | 2017 |
| Sous Arabia Ltd | Wholesale & retail | 2017 |
| South East Growth Fund Limited Partnership | | 2002 |
| Southern Rust Solutions Ltd | Wholesale & retail | 2025 |
| Southern Spices Burton Limited | Wholesale & retail | 2024 |
| Southern Spices Derby Ltd | Wholesale & retail | 2025 |
| Southshore Global Properties Limited | Real estate | 2025 |
| Southshore Motors Limited | Wholesale & retail | 2026 |
| Southwell Estates & Investments Limited | Real estate | 2025 |
| SOV Trans Limited | Transport & logistics | 2021 |
| Sova Engineering Ltd | Professional & scientific | 2025 |
| Sozr Health Care Ltd | Health & social care | 2024 |
| SP Property (PVT) Limited | Real estate | 2021 |
| Spaces Creative Limited | Professional & scientific | 2024 |
| Spacewefilled Ltd | Administrative & support | 2026 |
| Spanish Limited | Transport & logistics | 2024 |
| Sparkies VW Ltd | Wholesale & retail | 2016 |
| Sparkifix Ltd | Construction | 2025 |