| Squire Golf Limited | Manufacturing | 1999 |
| Squire Promotions Limited | Manufacturing | 1951 |
| SRC Advisors Limited | Professional & scientific | 2019 |
| SRE Conservatories, Windows & Doors Ltd | Construction | 2016 |
| SRL International Ltd | Professional & scientific | 2025 |
| SST Training & Development Ltd. | Administrative & support | 2010 |
| ST Athanasius Property Investment Ltd | Real estate | 2025 |
| ST Ediths Court (Kent) Limited | Households | 2018 |
| ST Helens 26 Freehold Ltd | Households | 2020 |
| ST Nicholas Court Management Company Limited | Households | 1997 |
| ST. Botolphs Avenue Management Company Limited | Households | 2011 |
| ST. Botolphs House Ltd | Real estate | 2023 |
| ST. James's Square Holdings Limited | Professional & scientific | 1999 |
| ST. James's Square Nominees Limited | Professional & scientific | 1999 |
| Stabilis Capital Limited | Real estate | 2020 |
| Stag Community Arts Centre | Arts & recreation | 2009 |
| Stag Community Arts Centre Trading Limited | Arts & recreation | 2011 |
| Stag Youth Theatre Ltd | Arts & recreation | 2020 |
| Stainless Steel Holding Limited | Administrative & support | 2009 |
| Stanbrook Abbey Hotel Limited | Hospitality | 2013 |
| Standard Business AI Generator Limited | Professional & scientific | 2017 |
| Stanford Accountancy & Management Limited | Professional & scientific | 2018 |
| Stanhope Medical Limited | Financial services | 2014 |
| Star Spangle Limited | Real estate | 2010 |
| Startpick Limited | Professional & scientific | 1990 |
| Stayora Ventures Ltd | Real estate | 2026 |
| Steadfast Services Ltd | Construction | 2023 |
| Steen FPM (UK) Limited | Manufacturing | 2009 |
| Stellar Building and Maintenance Ltd | Construction | 2019 |
| Stellprint Ltd | Professional & scientific | 2021 |
| Step Three Construction Limited | Construction | 2013 |
| Steph Parry Ltd | Arts & recreation | 2024 |
| Stephen Cooke Consultancy Limited | Professional & scientific | 2011 |
| Stephen Royce Ltd | Construction | 2022 |
| Stevensonwithers Associates Limited | Administrative & support | 2003 |
| Stevian Holdings Limited | Financial services | 2020 |
| Stidulph Capital Limited | Real estate | 2004 |
| Still Jarndyce Limited | Professional & scientific | 2009 |
| Stirling Financial Ltd | Construction | 2024 |
| Stirling Property Limited | Real estate | 2005 |
| Stns Construction Limited | Construction | 2015 |
| Stone Street Coffee Limited | Manufacturing | 2019 |
| Stonefield Estates, Limited | Real estate | 1936 |
| Stonefield Investments Limited | Real estate | 1937 |
| Stonehouse Building Services Ltd | Construction | 2024 |
| Stonehouse Electrical Ltd | Construction | 2014 |
| Stonehouse Workplace & Facilities Management Services Limited | Other services | 2018 |
| Stonewood Interiors Ltd | Construction | 2011 |
| Storm Financial Ltd | Information & communication | 2003 |
| Storybear Studios Limited | Information & communication | 2025 |
| Stovio Skills Limited | Professional & scientific | 2024 |
| Strada London Limited | Wholesale & retail | 2021 |
| Strategic Disciplines International Limited | Professional & scientific | 2016 |
| Strategy and Transformation Services Ltd | Professional & scientific | 2025 |
| Stratify Edge Consulting Limited | Information & communication | 2024 |
| Stratisec Ltd | Information & communication | 2023 |
| Stratistic Ltd | Information & communication | 2013 |
| Strawberry Audio Visual Ltd | Wholesale & retail | 2018 |
| Streamline Office Services (Kent) Limited | Administrative & support | 2018 |
| Streetvibes Dance Academy Ltd | Arts & recreation | 2021 |
| Streetvibes Studios Ltd | Arts & recreation | 2025 |
| Stringer Design Ltd | Information & communication | 2014 |
| Strong Healthcare Ltd | Administrative & support | 2015 |
| Strong Performance Wheels Limited | Wholesale & retail | 2026 |
| Strong Pillars Sales & Marketing Ltd | Wholesale & retail | 2024 |
| Stronghold Legacy Ltd | Real estate | 2018 |
| Structured Asset Finance Ltd | Financial services | 2021 |
| STS Property Solutions Ltd | Real estate | 2023 |
| Studio 107 Limited | Professional & scientific | 2024 |
| Studio 40 Art Ltd | Arts & recreation | 2025 |
| Studio DON Ltd | Professional & scientific | 2020 |
| Studio Gilchrist Limited | Professional & scientific | 2017 |
| Studio Hitchie Limited | Information & communication | 2024 |
| Studio NO. 17 Ltd | Professional & scientific | 2021 |
| Studio Pont Limited | Professional & scientific | 2011 |
| Studio Vespertine Ltd | Professional & scientific | 2024 |
| Sturla Consulting Ltd | Professional & scientific | 2024 |
| Styles Court (Paddock Wood) Management Limited | Households | 2003 |
| Styles Gardens Ltd | Administrative & support | 2008 |
| Stylesoflondonuk Ltd | Wholesale & retail | 2023 |
| Stylus Stationers Limited | Wholesale & retail | 2008 |
| Styrka Leotards Limited | Wholesale & retail | 2026 |
| Suave Resourcing Ltd | Professional & scientific | 2018 |
| Subliminal Consulting & Analytics Ltd | Extraterritorial | 2016 |
| SUE Hill Designs Limited | Manufacturing | 2011 |
| Sullivan & White Building Services Limited | Construction | 2025 |
| Sumaya Group Ltd | Professional & scientific | 2021 |
| Summerhill Court (Freehold) Company Limited | Households | 2009 |
| Sumtrust Ltd | Real estate | 2022 |
| Sundaisy Ltd | Manufacturing | 2024 |
| Sundownfilms Limited | Information & communication | 2024 |
| Sundridge Studio Limited | Wholesale & retail | 2025 |
| Sunflower (South East) Ltd | Real estate | 2013 |
| Sunlit Plains Limited | Financial services | 2025 |
| Sunlit Plains Productions Ltd | Information & communication | 2025 |
| Sunlit Plains Trading Ltd | Information & communication | 2025 |
| Sunspot Tours (Transportation) Limited | Administrative & support | 2003 |
| Sunspot Tours Limited | Administrative & support | 1979 |
| Superior Care Limited | Health & social care | 2008 |
| Superior Complex Care Limited | Extraterritorial | 2021 |