| Spreadborough Estates Limited | Real estate | 2023 |
| Spreadit Ltd | Construction | 2020 |
| Springboard Properties Limited | Real estate | 2026 |
| Springfield Contracting Ltd | Construction | 2020 |
| SPV Infotech Limited | Information & communication | 2012 |
| SPW Contractors (London & Essex) Ltd | Construction | 2020 |
| Square Project Ltd | Construction | 2013 |
| Squarebit Consulting Limited | Information & communication | 2011 |
| Squarecut Pictures Ltd | Information & communication | 2023 |
| Squirrel Electronics Limited | Professional & scientific | 1999 |
| SR Corporation Limited | Real estate | 2001 |
| SR Developments (UK) Limited | Construction | 2020 |
| SR Heaven Ltd | Real estate | 2023 |
| SR Terra Firma Limited | Professional & scientific | 2019 |
| SR Transport Consultants Ltd | Transport & logistics | 2021 |
| SR. GOS Ltd | Public administration | 2023 |
| SRA Transport Ltd | Transport & logistics | 2023 |
| SRC Flooring (UK) Limited | Construction | 2015 |
| SRI Arunachala Foods Limited | Hospitality | 2026 |
| SRI Consulting and Technologies Ltd | Information & communication | 2025 |
| SRI Durga Bhavani Ltd | Hospitality | 2023 |
| SRI SAI Second Investment Ltd | Real estate | 2025 |
| SRI Shanmukha Foods Limited | Hospitality | 2026 |
| Sria Infra Ltd | Real estate | 2022 |
| Srii Venkateshwara Ltd | Hospitality | 2026 |
| SRM Electrical and Fire Ltd | Construction | 2025 |
| Srph Solutions Limited | Information & communication | 2023 |
| Srra Transport Limited | Transport & logistics | 2026 |
| SRW Private Clinic Ltd | Health & social care | 2025 |
| SS City Plumbing Limited | Construction | 2014 |
| SS Food Consultancy Limited | Hospitality | 2023 |
| Ss&C Financial Services Europe Limited | Financial services | 1991 |
| Ss&C Financial Services International Limited | Information & communication | 1992 |
| Ss&C Trustees Limited | Financial services | 2001 |
| Sscp Limited | Construction | 2021 |
| Ssentials Ltd | Health & social care | 2013 |
| Sshr Properties Ltd | Real estate | 2022 |
| SSI Interiors Ltd | Construction | 2023 |
| SSJ Pizza Ltd | Hospitality | 2026 |
| SSJ Tanning Limited | Other services | 2017 |
| SSP Rileyway Limited | Construction | 2016 |
| Sss&S Decorating Ltd Ltd | Construction | 2022 |
| ST Extreme Cleaning Ltd | Administrative & support | 2019 |
| ST Facilities Limited | Construction | 2019 |
| ST Graphics LP | | 2016 |
| ST Lawrence Construction Limited | Professional & scientific | 2016 |
| ST Marks of London Limited | Construction | 2023 |
| ST Marks Union Limited | Construction | 2023 |
| ST Marys Associates Ltd | Information & communication | 2022 |
| ST Paul's Pre-School (Basildon) Limited | Education | 2013 |
| ST. Luke's Hospice (Basildon & District) Limited | Health & social care | 1984 |
| ST. Mawgan & Co Limited | Professional & scientific | 2003 |
| Stable Stay Management Ltd | Real estate | 2026 |
| Stack London Limited | Construction | 2013 |
| Stack Projects Limited | Professional & scientific | 2017 |
| Staff Roles Jobs Limited | Administrative & support | 2020 |
| Stagwell Electrical Contractors Ltd | Construction | 2022 |
| Stamford International Ltd | Administrative & support | 2021 |
| Stan Logistic Ltd | Transport & logistics | 2018 |
| Standout Performing Arts Ltd | Arts & recreation | 2019 |
| Stanford Supply Limited | Wholesale & retail | 2013 |
| Stanley Marsh & Company Limited | Real estate | 1944 |
| Stanlington NO. 2 PLC | Financial services | 2022 |
| Stanpwood Ltd | Construction | 2022 |
| Star and Light Evangelical Outreach Ltd | Other services | 2025 |
| Star Clean UK Ltd | Administrative & support | 2008 |
| Star Consulting Limited | Information & communication | 2015 |
| Star Drivers Academy Limited | Education | 2023 |
| Star EFX Theatre Productions Limited | Arts & recreation | 2023 |
| Star Electrical Controls Ltd | Construction | 2025 |
| Star Fitness Studio Ltd | Arts & recreation | 2023 |
| Star Notes Issuer 2022-1 Limited | Financial services | 2022 |
| Starcube Limited | Real estate | 2005 |
| Stares Engineering Ltd | Construction | 2024 |
| Starkeds Ltd | Information & communication | 2024 |
| Starlight Diligence Care Ltd | Health & social care | 2022 |
| Starnat Ltd | Health & social care | 2023 |
| Starrman Solutions Limited | Extraterritorial | 2011 |
| Stars Holdings Ltd | Real estate | 2024 |
| Starspoint Ltd | Construction | 2018 |
| Startstrong Fitness CIC | Education | 2023 |
| Station Nails MD Ltd | Other services | 2024 |
| Stay Executive Ltd | Administrative & support | 2025 |
| Stay Restaurant Group Limited | Hospitality | 2024 |
| Stay Safe International Limited | Administrative & support | 2020 |
| Staybright Energy Ltd | Construction | 2018 |
| Stayside Properties Limited | Real estate | 2003 |
| Stb&Bst Limited | Other services | 2017 |
| Steel and Pipe Solutions Limited | Professional & scientific | 2018 |
| Steel Art Scaffolding Limited | Construction | 2019 |
| Steel Banglez Limited | Information & communication | 2014 |
| Steel CAD Services Ltd | Professional & scientific | 2017 |
| Steel Frame Buildings Ltd | Construction | 2017 |
| Steel Wall Ltd | Professional & scientific | 2022 |
| Steeple Developments Limited | Construction | 2026 |
| Stef Fire Limited | Construction | 2011 |
| Stefan Installation Ltd | Construction | 2022 |
| Stefgen Ltd | Construction | 2020 |
| Stenil Limited | Administrative & support | 1983 |
| Step Styles Ltd | Wholesale & retail | 2025 |