| Spaceworks Project & Design MGT Ltd | Professional & scientific | 2018 |
| Spadvert Services Limited | Professional & scientific | 2021 |
| Spalter Fisher LLP | | 2010 |
| Sparkle Estates and Facilities Management Limited | Real estate | 2019 |
| Sparklingskinaesthetics Ltd | Health & social care | 2025 |
| Sparkrose Ltd | Extraterritorial | 2020 |
| Spat Prop Limited | Real estate | 2023 |
| Spatariu Ltd | Construction | 2026 |
| Spdq Ltd | Information & communication | 2018 |
| Special Blend Props Ltd | Information & communication | 2021 |
| Specialist Digital Marketing and SEO Ltd | Information & communication | 2026 |
| Specs Gonzalez Holdings Limited | Financial services | 2026 |
| Specs Gonzalez Management Limited | Administrative & support | 2026 |
| Specs Gonzalez Productions Limited | Information & communication | 2026 |
| Speedway Limited | Hospitality | 2007 |
| Speedy Building Ltd | Real estate | 2015 |
| Spencer Fire Protection Ltd | Construction | 2026 |
| Spenoyd Limited | Real estate | 2016 |
| Spi.London Limited | Administrative & support | 2016 |
| Spice of Life (South West Midlands) Ltd | Health & social care | 2021 |
| Spice Tandoori Liverpool Limited | Hospitality | 2019 |
| Spiderhub Limited | Information & communication | 2023 |
| Spinecare Ltd | Health & social care | 2020 |
| Spivack Investments Limited | Financial services | 2023 |
| Splash Prestige Motors Limited | Wholesale & retail | 2014 |
| Split Decision Limited | Professional & scientific | 2025 |
| SPM Marketing Limited | Administrative & support | 2017 |
| Spondeo Homes Ltd | Real estate | 2019 |
| Spoof.Global Limited | Wholesale & retail | 2020 |
| Sport on Spec Limited | Information & communication | 2012 |
| Sporty Heroes Ltd | Health & social care | 2026 |
| Spray Foam Removal Experts Ltd | Administrative & support | 2023 |
| Spraycandi Ltd | Administrative & support | 2021 |
| Spring Block Property Management Limited | Real estate | 2026 |
| Spring Partners Estates Limited | Real estate | 2014 |
| Springers (Freehold) Limited | Households | 2014 |
| Spruce Property Solutions LLP | | 2022 |
| SPV Business & Co Ltd | Administrative & support | 2025 |
| SPW Residential Investments Limited | Real estate | 2021 |
| SPY Tech Limited | Information & communication | 2023 |
| SQ Properties (Chadwell Heath) Limited | Real estate | 2006 |
| Squad Accounting and Tax Services Ltd | Professional & scientific | 2018 |
| Square Eyed Pictures Ltd | Information & communication | 2022 |
| Squared Intelligence Limited | Information & communication | 2014 |
| Squires Court Highworth Management Company Limited | Households | 2012 |
| SR Fitzgerald Limited | Information & communication | 2022 |
| SR Health Limited | Health & social care | 2012 |
| SR Property Rentals Limited | Real estate | 2017 |
| SR Services and Solutions Ltd | Information & communication | 2016 |
| Sramek Yearwood Ltd | Professional & scientific | 2025 |
| Sran Properties & Investments Ltd | Real estate | 2016 |
| SRB Lets Limited | Real estate | 2007 |
| SRC Healthcare Ltd | Health & social care | 2016 |
| SRC SPV Ltd | Financial services | 2024 |
| SRD Productions Limited | Information & communication | 2006 |
| Sree SAI Properties Ltd | Real estate | 2024 |
| SRI Lankan Women Cricket League Ltd | Arts & recreation | 2026 |
| SRI London Ltd | Arts & recreation | 2025 |
| SRI Sainath Medical Services Ltd | Health & social care | 2017 |
| SRJ Accounting Services Limited | Professional & scientific | 1995 |
| SRV Property Group Limited | Real estate | 2021 |
| Srvd Limited | Health & social care | 2024 |
| SS Foodz Ltd | Financial services | 2019 |
| SS Skanda Limited | Health & social care | 2019 |
| Ssdn Anand Ltd | Real estate | 2019 |
| SSG Security Services Ltd | Administrative & support | 2020 |
| SSH Apps Limited | Information & communication | 2009 |
| SSP Construction Ltd | Construction | 2018 |
| ST Albans Home Cinema Company Ltd | Wholesale & retail | 2020 |
| ST George Healthcare Limited | Health & social care | 1999 |
| ST Gohil Property Limited | Real estate | 2023 |
| ST Mobile Carwash Limited | Wholesale & retail | 2025 |
| ST Nicholas London Limited | Real estate | 2013 |
| ST Stag Ltd | Construction | 2024 |
| ST. John's Preparatory & Senior School Limited | Education | 2004 |
| ST. Stephens Close (Residents Association) Limited | Households | 1996 |
| St.Peter's Close Residents Association Limited | Households | 1971 |
| Stable Silks Investments Limited | Arts & recreation | 2023 |
| Stacey Cowen & Associates Limited | Professional & scientific | 2013 |
| Stacey Dooley Productions Limited | Information & communication | 2018 |
| Stafflocks Ltd | Financial services | 2023 |
| Stag & Grip Ltd | Construction | 2019 |
| Stag IT RJD Limited | Construction | 2015 |
| Stagecraft Ltd | Construction | 2022 |
| Stags Construct Ltd | Information & communication | 2026 |
| Stair Master Ltd | Manufacturing | 2008 |
| Stalion Prestige Motors Ltd | Wholesale & retail | 2026 |
| Stamp Duty Rebate Ltd | Administrative & support | 2021 |
| Stan Waste Removals Limited | Water & waste | 2015 |
| Stanborough Holdings Ltd | Professional & scientific | 2008 |
| Stanborough Leisure Limited | Construction | 1997 |
| Stanciuc Contractors Ltd | Construction | 2007 |
| Standon Mill Residents Company Limited | Households | 2004 |
| Standric Flat Management Limited | Households | 1997 |
| Stanilov Medical Ltd | Health & social care | 2020 |
| Stanley Court (Freehold) Limited | Households | 1995 |
| Stanley Court (Gloucester) Management Ltd | Real estate | 2010 |
| Stanley Court Management (Chichester) Ltd | Real estate | 2022 |
| Stanley Court Management Company (Stanmore) Limited | Households | 1973 |
| Stanley Dock Hotel Limited | Hospitality | 2012 |