| Specialist Production Event Exhibition and Design Limited | Other services | 2002 |
| Spectra Interiors Limited | Construction | 2020 |
| Spectrum Environmental Limited | Professional & scientific | 1995 |
| SPEEDPAWTRANS29310 Ltd | Transport & logistics | 2025 |
| Spencer Catering Services Limited | Hospitality | 2019 |
| SPG Group Ltd | Professional & scientific | 2021 |
| Spiderzone Limited | Manufacturing | 2000 |
| Spingenuity Ltd | Manufacturing | 2026 |
| Spires Scaffolding Limited | Construction | 2025 |
| Spit Nights Ltd | Arts & recreation | 2024 |
| Sportsvibe Limited | Administrative & support | 2017 |
| Spraying Systems Limited | Wholesale & retail | 1993 |
| Spring Garden House Ltd | Hospitality | 2017 |
| Spring Head Securities Limited | Real estate | 1978 |
| Spring View Healthcare Ltd | Health & social care | 2020 |
| Springfield Construction Limited | Construction | 2024 |
| Springfield International Investments Limited | Administrative & support | 2021 |
| SPS Digital Mailing Limited | Administrative & support | 2004 |
| SPW Construction Engineering Limited | Construction | 2007 |
| SPX Brands UK PVT. Ltd | Wholesale & retail | 2019 |
| Sqryl Limited | Manufacturing | 2025 |
| Square Peak Ltd | Real estate | 2024 |
| SRC Capital Limited | Administrative & support | 2025 |
| SS Business Limited | Wholesale & retail | 2017 |
| SS Housing Ltd | Real estate | 2024 |
| SSG Designs Limited | Professional & scientific | 2023 |
| ST Andrews Carpet Company Holdings Limited | Administrative & support | 2021 |
| ST Andrews Carpet Company Limited | Wholesale & retail | 2009 |
| ST. Catherines Limited | Real estate | 1997 |
| ST. Mary Pharmacy Limited | Health & social care | 2003 |
| Stable Wall Ltd | Administrative & support | 2012 |
| Star Crossed Productions Limited | Administrative & support | 2020 |
| Stardio Ltd | Arts & recreation | 2020 |
| Starflex Packaging Europe Limited | Administrative & support | 2008 |
| Starflex Weighing Systems Limited | Administrative & support | 2014 |
| Starley Toys Limited | Wholesale & retail | 2024 |
| Starling Executive Travel Ltd | Transport & logistics | 2026 |
| Starling RA Limited | Wholesale & retail | 2025 |
| Statistics and Strategies Limited | Professional & scientific | 2007 |
| Staverton Flying School @ Skypark Limited | Transport & logistics | 2010 |
| Stay Country LLP | | 2026 |
| Steadfast Industries Limited | Financial services | 2023 |
| Steadfast Solutions Limited | Manufacturing | 2006 |
| Steam Easy Limited | Administrative & support | 2003 |
| Steed and Daughters Limited | Financial services | 2018 |
| Stephen Wakeman GAS Plumbing and Heating Services Ltd | Construction | 2019 |
| Stephill Investments Ltd | Administrative & support | 2018 |
| Sterling Power Products (Holdings) Limited | Manufacturing | 2013 |
| Sterling Power Products Limited | Manufacturing | 2005 |
| Sterne Holdings Ltd | Financial services | 2022 |
| Steve Roberts Investments Ltd | Real estate | 2017 |
| Sticmezt Ltd | Transport & logistics | 2021 |
| Stilgoe Holdings Limited | Financial services | 2021 |
| Stilgoe Property Management Limited | Real estate | 2019 |
| Still Induction Heating Equipment Limited | Manufacturing | 2014 |
| Still Induction Heating Limited | Manufacturing | 2011 |
| Stoplas Ltd | Manufacturing | 2023 |
| Storm Logistics Ltd | Transport & logistics | 2025 |
| Storm Roofing (UK) Limited | Construction | 2008 |
| Stormfour Ltd | Information & communication | 2019 |
| Storrage House Ltd | Health & social care | 2019 |
| Stortford Limited | Professional & scientific | 2023 |
| Stour Precision Tools Limited | Manufacturing | 1966 |
| Strategic Sourcing & Procurement Innovation Ltd | Professional & scientific | 2021 |
| Strathblaine Media Limited | Information & communication | 2011 |
| Stratospheria Ltd | Arts & recreation | 2021 |
| Strikersoft UK Limited | Information & communication | 2018 |
| Strongoak Commerce Limited | Financial services | 2022 |
| Strongoak Consultancy Ltd | Professional & scientific | 2015 |
| Strongoak Education Ltd | Education | 2018 |
| Strongoak Holdings Limited | Financial services | 2017 |
| Strongoak Investments Ltd | Real estate | 2016 |
| Strongoak Lettings Limited | Construction | 2021 |
| Strongoak Trading Group Limited | Financial services | 2024 |
| Stuart Sinclair Silverware Limited | Manufacturing | 2006 |
| Studio Fourteen Interiors Limited | Construction | 2017 |
| Studio Fourteen Limited | Professional & scientific | 2011 |
| Stuk Products Limited | Wholesale & retail | 2008 |
| Stux Ltd | Wholesale & retail | 2024 |
| STW Training Limited | Other services | 2005 |
| Styles Holding Co Limited | Financial services | 2022 |
| Success Holdings Limited | Professional & scientific | 2009 |
| Sulhum Investments Limited | Administrative & support | 2018 |
| Sulhum Limited | Real estate | 2017 |
| Summer REP Season Limited | Arts & recreation | 2016 |
| Sumputh Limited | Real estate | 2019 |
| Sun Test Systems Limited | Manufacturing | 2007 |
| Sundial House Interiors (Campden) Limited | Professional & scientific | 2019 |
| Super Foam Car Wash Ltd | Other services | 2022 |
| Superior Barber 1 Ltd | Other services | 2024 |
| Surebase Limited | Information & communication | 1983 |
| Sureenergy Projects Limited | Administrative & support | 2014 |
| Sureseal Investments Limited | Real estate | 2021 |
| Sureseal Windows Midlands Ltd | Construction | 2002 |
| Sustainable Development Goals Limited | Administrative & support | 2023 |
| Sustainable Properties Powys Limited | Administrative & support | 2013 |
| SVP Cheshire Limited | Professional & scientific | 2022 |
| Swift Hospitality Limited | Hospitality | 2023 |
| Swinc Limited | Wholesale & retail | 2023 |
| Swordfish Wireless Networks Limited | Information & communication | 2025 |