| Smartworld Tech Ltd | Information & communication | 2018 |
| Smartypants Petts Wood Limited | Other services | 2023 |
| SMC Financial Management Ltd | Information & communication | 2012 |
| SMC Medix Ltd | Health & social care | 2009 |
| Smilemaker Dental Practice Limited | Health & social care | 2011 |
| Smith & Jones Consultants Limited | Information & communication | 2002 |
| Smith and Hogan Limited | Other services | 2020 |
| Smith Ecoflow Ltd | Construction | 2026 |
| Smith Stone & Brickwork Limited | Construction | 2021 |
| Smoke Productions Limited | Information & communication | 2007 |
| SMP Transformations Ltd | Other services | 2025 |
| Smrthi Ltd | Wholesale & retail | 2025 |
| SMS South East Ltd | Professional & scientific | 2012 |
| SMT Takeaway Ltd | Hospitality | 2025 |
| Smyle Design Limited | Administrative & support | 2004 |
| Snelgrove Property Ltd | Real estate | 2026 |
| Snow Pebbles Services Limited | Professional & scientific | 2018 |
| Snowcare Co Limited | Health & social care | 2024 |
| SNS Solutions Ltd | Manufacturing | 2013 |
| Snughaus Ltd | Construction | 2024 |
| SO Appy Limited | Administrative & support | 2024 |
| SO Clean Cleaning & Support Services Limited | Administrative & support | 2018 |
| SO Greene Limited | Water & waste | 2021 |
| So-In Kitchen Ltd | Hospitality | 2026 |
| Soar Estates Limited | Real estate | 2020 |
| Social Athletes Ltd | Information & communication | 2022 |
| Social Care Solutions Consultancy Ltd | Health & social care | 2022 |
| Softcode London Ltd | Information & communication | 2017 |
| SOFTWARE4NG Ltd | Administrative & support | 2017 |
| SOL4LIFE Ltd | Wholesale & retail | 2026 |
| Sola Holdings Inc Ltd | Real estate | 2024 |
| Solar Power London Ltd | Construction | 2024 |
| Sole Moraine Ltd | Manufacturing | 2017 |
| Solec Construction Limited | Construction | 2026 |
| Solec Energy Ltd | Construction | 2024 |
| Solequa Limited | Wholesale & retail | 2017 |
| Solhan 1 Ltd | Hospitality | 2019 |
| Solico Builders Ltd | Construction | 2008 |
| Solid FAB (Kent) Limited | Manufacturing | 2021 |
| Solid Rock Estates Ltd | Real estate | 2017 |
| Solid Rock Estates Services Limited | Real estate | 2025 |
| Solidus Limited | Construction | 2021 |
| Solj Holdings Limited | Financial services | 2026 |
| Soloman Builders Limited | Construction | 2018 |
| Solved Engineering Ltd | Professional & scientific | 2011 |
| Solway House Management Limited | Households | 2006 |
| Somsint Limited | Information & communication | 2016 |
| Sonda Services Limited | Information & communication | 2021 |
| Sonia Lopez Fitness and Wellbeing Ltd | Health & social care | 2021 |
| Sony Joseph Ltd | Information & communication | 2026 |
| Soro Group Ltd | Transport & logistics | 2019 |
| Sorrell Surveying Services Limited | Professional & scientific | 2015 |
| Soul Armour Ltd | Information & communication | 2009 |
| Sound With US Events Ltd | Arts & recreation | 2017 |
| Sourced Buy Limited | Wholesale & retail | 2025 |
| South East BUS Supplies (Kent) Limited | Transport & logistics | 2018 |
| South East BUS Supplies Limited | Wholesale & retail | 2010 |
| South East Film Ltd | Information & communication | 2022 |
| South East Property Holdings Limited | Real estate | 2026 |
| South East Roofing and Cladding Limited | Construction | 2023 |
| South London Mast Limited | Real estate | 2018 |
| South Orpington Learning Alliance Multi-Academy Trust | Education | 2012 |
| South Street Property Management (Haywards Heath) Limited | Real estate | 2023 |
| Southeast Asian Food Ltd | Hospitality | 2020 |
| Southeast Legacies Ltd | Professional & scientific | 2019 |
| Southern Soul Limited | Hospitality | 2022 |
| Southline Inspection Services Ltd | Professional & scientific | 2026 |
| Southside Property Management Services Ltd | Real estate | 2005 |
| Sovereign Complete Property Services Ltd. | Real estate | 2017 |
| Sovereign Management Ltd | Real estate | 2026 |
| Sovereign Suites Ltd | Real estate | 2024 |
| Spa Investors Limited | Real estate | 2024 |
| Spa Scitech Limited | Professional & scientific | 2022 |
| Space Click Ltd | Transport & logistics | 2025 |
| Spark IT Services Limited | Information & communication | 2020 |
| Sparkling Electrical Ltd | Manufacturing | 2023 |
| Sparkster Limited | Construction | 2018 |
| Sparmi Limited | Information & communication | 2024 |
| Sparq Creative Limited | Professional & scientific | 2012 |
| Sparsh & Span Ltd | Real estate | 2023 |
| Sparticus Developments Ltd | Construction | 2024 |
| Sparticus Properties Ltd | Construction | 2024 |
| Spatial Consulting Ltd | Information & communication | 2026 |
| Spatialgb Ltd | Information & communication | 2023 |
| Spcuk LLP | | 2015 |
| Specac Holdco Limited | Financial services | 2024 |
| Specac International Limited | Financial services | 2015 |
| Specac Limited | Manufacturing | 1971 |
| Spectra Services Ltd | Transport & logistics | 2020 |
| Speed Finishers Limited | Manufacturing | 2023 |
| Speed Star Promotions Meets Box Nxation LLP | | 2025 |
| Speedy Cars (UK) Ltd | Transport & logistics | 2012 |
| Spekbilt Limited | Construction | 2026 |
| Spence Recruitment Ltd | Administrative & support | 2015 |
| Spiering Media Limited | Professional & scientific | 2014 |
| Spike Lifting Services Ltd | Construction | 2015 |
| Spilsbury Ward Limited | Professional & scientific | 2017 |
| Spirit D M Limited | Manufacturing | 2010 |
| Spitfire Garage Doors Limited | Construction | 2019 |
| Spools OUT Productions Limited | Arts & recreation | 2014 |