| S&W Letting Solutions Limited | Real estate | 2013 |
| S. Webb Building & Plastering Limited | Construction | 2003 |
| Saaria Limited | Administrative & support | 2021 |
| Saasdragon Ltd | Professional & scientific | 2022 |
| Sabayjai Thai Therapy Ltd | Other services | 2008 |
| Sabreline (UK) Limited | Manufacturing | 2005 |
| Sacred Estates Limited | Real estate | 2024 |
| Safe Accountancy Limited | Professional & scientific | 2020 |
| Safe Consultancy London Ltd | Professional & scientific | 2021 |
| Saffiana Ltd | Information & communication | 2017 |
| Saffron Fusions Limited | Hospitality | 2026 |
| Sage & Sage Ltd | Administrative & support | 2018 |
| Sages Education Limited | Education | 2024 |
| Sagr Consulting Limited | Professional & scientific | 2024 |
| Sagwal & Co UK Ltd | Wholesale & retail | 2026 |
| Sahara Technologies Ltd. | Professional & scientific | 2014 |
| SAI Children Centre Ltd | Health & social care | 2010 |
| Saidden Ltd | Professional & scientific | 2025 |
| Saint Margaret's Ventures Limited | Administrative & support | 2025 |
| Saipan Construction Ltd | Construction | 2023 |
| Sake Limited | Real estate | 1998 |
| Salaries Selective Ltd | Professional & scientific | 2009 |
| Salisbury Building & Plant Maintenance Ltd | Other services | 2008 |
| Sallaku Farm Limited | Hospitality | 2021 |
| Salt and Vinegar Fish Bar Limited | Hospitality | 2023 |
| Salt and Vinegar Twickenham Ltd | Hospitality | 2026 |
| Salt Studios Wellness Ltd | Other services | 2025 |
| Saltburn House Mgmt Limited | Households | 2020 |
| Salts Consulting Limited | Information & communication | 2017 |
| Salty Restaurant Ltd | Hospitality | 2020 |
| Salvere Consulting Limited | Professional & scientific | 2011 |
| SAM Day Ltd | Information & communication | 2024 |
| Sama Veda Ltd | Wholesale & retail | 2023 |
| Samels Court (W6) Limited | Households | 1995 |
| Sami's Hair & Beauty Limited | Other services | 2020 |
| Samlar Limited | Extraterritorial | 2021 |
| Samrai Arts Ltd | Arts & recreation | 2018 |
| Samsoft Solutions Ltd | Information & communication | 2010 |
| Sanaa Properties Ltd | Real estate | 2018 |
| Sanaahar Limited | Real estate | 2021 |
| Sanctuary Events Ltd | Arts & recreation | 2020 |
| Sanctum Imports & Distribution Limited | Wholesale & retail | 2025 |
| Sanctum Services Limited | Information & communication | 2008 |
| Sandra Griffin Management Limited | Administrative & support | 2003 |
| Sane Investments Ltd | Real estate | 2018 |
| Sangita Trade Limited | Real estate | 2025 |
| Sanharsha Limited | Real estate | 2018 |
| Santiago Restaurant Ltd | Hospitality | 2023 |
| Sapphire Blue Boutique Ltd | Wholesale & retail | 2017 |
| Sapphire INT Ltd | Wholesale & retail | 2018 |
| Sapphire Skies Media Ltd | Manufacturing | 2017 |
| Saralotte Limited | Financial services | 2011 |
| Sarsfield Associates Ltd | Construction | 1989 |
| SAS Beauty Ltd | Other services | 2022 |
| SAS Plumbing Ltd | Construction | 2026 |
| Sathya Care Ltd | Health & social care | 2018 |
| Sathya Medics Limited | Health & social care | 2015 |
| Savvy IQ Consulting Ltd | Professional & scientific | 2026 |
| Savvykidz Limited | Education | 2014 |
| SAX Healthcare Limited | Health & social care | 2026 |
| Saynama Ltd | Wholesale & retail | 2020 |
| Sayurit Sushi Ltd | Hospitality | 2018 |
| SB Spray Ltd | Construction | 2019 |
| SBM Accountancy Ltd | Professional & scientific | 2016 |
| Sbmosaic Ltd | Manufacturing | 2013 |
| Sbtf Publishing Ltd | Information & communication | 2015 |
| Scarsdale (UK) Limited | Real estate | 2011 |
| Science Defied Limited | Information & communication | 2009 |
| SCM Financial Holdings Ltd | Professional & scientific | 2024 |
| Scoliosisuk Limited | Health & social care | 2015 |
| Scorpian Industries Limited | Professional & scientific | 2005 |
| Scotia Philately Limited | Wholesale & retail | 1984 |
| Scott Castillo Property Ltd | Real estate | 2024 |
| Scott Co Consulting Ltd | Information & communication | 2025 |
| Scrambled Books Ltd | Administrative & support | 2025 |
| Screen Play London Limited | Arts & recreation | 2013 |
| Sculpt Your Skills Ltd | Arts & recreation | 2021 |
| SD Construction London Ltd | Construction | 2024 |
| Sean B Ltd | Arts & recreation | 2016 |
| Seascape Properties Ltd | Real estate | 2023 |
| Seawing-Ilk General Contractors Limited | Professional & scientific | 2025 |
| Seba JUH Ltd | Transport & logistics | 2019 |
| Sebastian George Limited | Professional & scientific | 2012 |
| Sebram Limited | Real estate | 2014 |
| Secret Garden Caffe Ltd | Hospitality | 2018 |
| Secret Starbase Ltd | Information & communication | 2025 |
| Seed Accounting Solutions Ltd | Professional & scientific | 2014 |
| Sehgal Brothers Limited | Wholesale & retail | 2004 |
| Selene Collective Ltd | Real estate | 2026 |
| Selfie Optic Limited | Wholesale & retail | 2020 |
| Selwyn Avenue Limited | Real estate | 2020 |
| Sema Childcare Ltd | Health & social care | 2019 |
| Sema Invest Limited | Professional & scientific | 2022 |
| Senda Holdings Ltd | Financial services | 2024 |
| Senior Leader Strategic Support Ltd | Professional & scientific | 2015 |
| Senior Property Portfolio Ltd | Real estate | 2026 |
| Sennen Studio Ltd | Professional & scientific | 2023 |
| Senseful Ltd | Information & communication | 2025 |
| Senseofduty Media Ltd | Information & communication | 2021 |
| Sequin Souls Limited | Other services | 2021 |