| Stallor Heavy Truck Service Limited | Wholesale & retail | 2026 |
| Stamford Brook Consulting Ltd | Professional & scientific | 2025 |
| Standard Corporation Limited | Real estate | 2003 |
| Standard Jeans Limited | Manufacturing | 2005 |
| Standor Holdings Ltd | Financial services | 2025 |
| Standor House (UK) Limited | Real estate | 2014 |
| Stannard Pressure Wash Ltd | Administrative & support | 2024 |
| Star Anise Ltd | Hospitality | 2024 |
| Star Hawk Investments Limited | Real estate | 2020 |
| Star Property Management Limited | Real estate | 2003 |
| Star Style Luxury Limited | Wholesale & retail | 2020 |
| Stateart Limited | Energy | 2004 |
| Station Convenience Store Limited | Wholesale & retail | 2017 |
| Stayhead Limited | Professional & scientific | 2018 |
| Staymire Flat Management Company Limited | Households | 1982 |
| Stefanel Construction Ltd | Construction | 2025 |
| Stellar Smiles Ltd | Health & social care | 2023 |
| Stephen and Cavalli Ltd | Construction | 2016 |
| Stephen Speller Golf Professional Limited | Arts & recreation | 2010 |
| Stephenson House Management Company 2015 Ltd | Real estate | 2015 |
| Sterling Dental Centres Limited | Health & social care | 2023 |
| Sterling Dental College Limited | Health & social care | 2023 |
| Sterling Dental Group Limited | Health & social care | 2024 |
| Steve Charles Electrical Ltd | Construction | 2011 |
| Steve's Barbers Limited | Other services | 2006 |
| Steven Paul Construction Limited | Construction | 2008 |
| Steven Sara Limited | Professional & scientific | 2011 |
| Stewarts Electrical Limited | Construction | 2018 |
| Stickysites Ltd | Information & communication | 2025 |
| Stinky POO Bar Limited | Hospitality | 2026 |
| Stjameses Limited | Wholesale & retail | 2005 |
| Stock Conversion Limited | Administrative & support | 2017 |
| Stockham Paddocks Management Ltd | Households | 2024 |
| Stompbox Ltd | Wholesale & retail | 2008 |
| Stompbox Music School Ltd | Education | 2013 |
| Stone Ties Ltd | Administrative & support | 2024 |
| Stonebury Properties Limited | Financial services | 2008 |
| Stonehill House Gardens Ltd | Administrative & support | 2025 |
| Stop, Think Property Limited | Real estate | 2006 |
| Stork & MAY Careers Limited | Professional & scientific | 2006 |
| Stratowings Limited | Administrative & support | 2020 |
| Street Enterprises Ltd | Information & communication | 2011 |
| Streetwell Limited | Hospitality | 2017 |
| Stuart Williams Agencies Limited | Wholesale & retail | 2010 |
| Studio 94 Salons Limited | Other services | 2019 |
| Studio ADB Limited | Arts & recreation | 2015 |
| Studio Housing Ltd | Hospitality | 2018 |
| Studio MO2 Limited | Professional & scientific | 2017 |
| Studio SH Creatives Ltd | Information & communication | 2025 |
| Studio Viii Dental & Facial Aesthetics Ltd | Health & social care | 2021 |
| Style by Manisha Limited | Professional & scientific | 2017 |
| Stylease Ltd | Wholesale & retail | 2020 |
| Subira Consulting Ltd | Professional & scientific | 2015 |
| Success Leaves Clues Ltd | Arts & recreation | 2019 |
| Sugalicious by Ridhima Mehta Limited | Wholesale & retail | 2018 |
| Suhail Rashid Ltd | Health & social care | 2015 |
| Sullivan Builders (London) Ltd | Construction | 2019 |
| Sundent Ltd | Health & social care | 2023 |
| Sunray Home Investment Ltd | Real estate | 2019 |
| Suntech Software Solutions Ltd | Information & communication | 2012 |
| Superglobal Studios Holdings Limited | Information & communication | 2025 |
| Superhire Limited | Administrative & support | 1997 |
| Supernova Wedding Boutique Limited | Wholesale & retail | 2016 |
| SUR ROD Ltd | Wholesale & retail | 2022 |
| Suvin Investments Limited | Financial services | 2020 |
| Svna-G Properties Ltd | Real estate | 2025 |
| Swan London Properties Limited | Real estate | 2016 |
| Swedice Ltd | Manufacturing | 2022 |
| Swiss Care Clinic Limited | Other services | 2006 |
| Swiss Star Ltd | Hospitality | 2025 |
| Syal Mandan Estates Ltd | Real estate | 2024 |
| Syen Ltd | Professional & scientific | 2021 |
| Syenlet Ltd | Real estate | 2022 |
| Synapsis Health Ltd | Health & social care | 2023 |
| Synchrotex Limited | Wholesale & retail | 2019 |
| Synergize Advisory Limited | Wholesale & retail | 2020 |
| Synergy Care Developments (Radcliffe) Ltd | Construction | 2024 |
| Synergy Care Developments Ltd | Construction | 2023 |
| Synergy Care Group Ltd | Health & social care | 2023 |
| Synersys Solutions Limited | Information & communication | 2008 |
| Syon (Forest Hill) Limited | Real estate | 2019 |
| SYT Properties Ltd | Real estate | 2021 |
| Szar Consulting Ltd | Real estate | 2018 |
| T & T Consulting (Pinner) Limited | Professional & scientific | 2010 |
| T L Mason & Sons (Property) Limited | Real estate | 1978 |
| T. BRO Investment Limited | Real estate | 1995 |
| T.A.Y. Transport Ltd | Transport & logistics | 2022 |
| Taaji Ltd | Real estate | 2026 |
| Tabea Solutions Limited | Information & communication | 2013 |
| TAI PAN Express Limited | Hospitality | 2022 |
| TAI PAN Oriental Limited | Hospitality | 2022 |
| Take Care of the Bills Limited | Information & communication | 2019 |
| Talwars & Co Limited | Real estate | 2014 |
| TAM Peri Peri Ltd | Hospitality | 2022 |
| Tanco Properties Limited | Real estate | 2003 |
| Tanj Capital Limited | Real estate | 2025 |
| Tapestry Holdings Limited | Information & communication | 2015 |
| Tara Property Management Ltd | Administrative & support | 2001 |
| Taranis Technology Consulting Limited | Information & communication | 2020 |
| Tariffsign Limited | Construction | 1985 |