| Sharma Capital Partners Ltd | Professional & scientific | 2018 |
| Sharma Engineering Services Ltd | Professional & scientific | 2026 |
| Shaun Cooper Properties Ltd | Real estate | 2024 |
| Shawarma Grill Leamington Spa Limited | Hospitality | 2018 |
| Shaz Prime Properties Limited | Real estate | 2025 |
| She's SO Money Limited | Professional & scientific | 2022 |
| Shebang Design & Marketing Limited | Professional & scientific | 2013 |
| SHED63 Ltd | Manufacturing | 2018 |
| Shera Digital Ltd | Information & communication | 2026 |
| Sheraton Leet Investments Limited | Construction | 2000 |
| Sheridan Electrical Contracting Ltd | Construction | 2025 |
| Shesells Consulting Limited | Professional & scientific | 2018 |
| Shiftec (Leamington) Limited | Manufacturing | 2015 |
| Shiftec (Willenhall) Limited | Manufacturing | 2015 |
| Shiftec Composites Limited | Manufacturing | 2015 |
| Shiftec Ltd | Administrative & support | 2007 |
| Shiftec Manufacturing Limited | Manufacturing | 2015 |
| Shinra Labs Ltd | Information & communication | 2025 |
| Shipston DRY Cleaning Limited | Other services | 2014 |
| Shipston Express Limited | Other services | 2026 |
| Shire Auto Care Ltd | Wholesale & retail | 2026 |
| Shire Foods of Warwick Limited | Extraterritorial | 2009 |
| Shire Hospitality Ltd | Hospitality | 2025 |
| Shire Midlands Group Ltd | Financial services | 2023 |
| SHN Property LLP | | 2026 |
| Shoffa Jewellers & Textiles UK Limited | Wholesale & retail | 2012 |
| Shokarz Limited | Extraterritorial | 2008 |
| Shoo 188 Limited | Financial services | 2024 |
| Shopwiteaze Foods Limited | Wholesale & retail | 2023 |
| Shopwiteaze Limited | Wholesale & retail | 2023 |
| Shoqeen Ltd | Wholesale & retail | 2024 |
| Shoulder and Elbow Solutions Ltd | Health & social care | 2015 |
| Showlec Limited | Construction | 2012 |
| Shradha RAO Limited | Professional & scientific | 2022 |
| Siam Access Limited | Professional & scientific | 2009 |
| Siamatas Design Limited | Professional & scientific | 2015 |
| Siamatas Property Limited | Real estate | 2020 |
| Sian Dumas Ltd. | Administrative & support | 2020 |
| Sicilian Pizza & Kebab Limited | Hospitality | 2021 |
| Sidson Holdings Limited | Administrative & support | 2024 |
| Sidwell & Kaye Limited | Extraterritorial | 1975 |
| Sigell UK Limited | Information & communication | 2007 |
| Sigma Beauty Ltd | Other services | 2023 |
| Sigma Digital Marketing Ltd | Information & communication | 2014 |
| Sigma Finance Limited | Financial services | 2002 |
| Sigmatek Automation UK Limited | Manufacturing | 2011 |
| Signal Construction (Midlands) Limited | Construction | 2008 |
| Siia Limited | Wholesale & retail | 2020 |
| Silicon Brick Ltd | Construction | 2019 |
| Siliu Solutions Ltd | Construction | 2010 |
| Silk & Spice Leamington Spa Limited | Hospitality | 2025 |
| Silver Cloud Enterprises Ltd | Financial services | 2024 |
| Silver Lake Developments Limited | Real estate | 2021 |
| Silver Lake Studio Limited | Professional & scientific | 2016 |
| Silver Sky Textiles Limited | Information & communication | 2015 |
| Silverleaf Capital Limited | Real estate | 2018 |
| SIM K Investments Limited | Real estate | 2019 |
| Simec (Australia) UK Ltd | Financial services | 2017 |
| Simec Highland Hydro Renewables Holdings Ltd | Financial services | 2017 |
| Simec Holdings (Mining) UK Ltd | Financial services | 2017 |
| Simec Holdings (Ports) UK Ltd | Financial services | 2017 |
| Simec Investments 51 Ltd. | Real estate | 2016 |
| Simec Investments 52 Limited | Real estate | 2018 |
| Simec Lochaber Hydropower 2 Limited | Energy | 1963 |
| Simkus Solutions Limited | Information & communication | 2023 |
| Simlectric Limited | Extraterritorial | 2021 |
| Simmba Ventures Limited | Hospitality | 2024 |
| Simon Baldwin Electrical Limited | Construction | 2009 |
| Simon Brain Builder Limited | Construction | 2016 |
| Simon Skellon Consulting Ltd | Professional & scientific | 2025 |
| Simpact Engineering Limited | Professional & scientific | 2000 |
| Simplified Supply Chain Ltd | Professional & scientific | 2024 |
| Simpson Financial Services Ltd | Financial services | 2003 |
| Singapore Sling Limited | Hospitality | 2019 |
| Singhs Fitting Things Limited | Construction | 2020 |
| SIR Property Holdings Limited | Real estate | 2025 |
| Siren's Amphora Ltd | Wholesale & retail | 2023 |
| Sirett Ltd | Professional & scientific | 2010 |
| Sirius Automotive Limited | Manufacturing | 2014 |
| Sirius Nexus Ltd | Professional & scientific | 2022 |
| Siswala Limited | Wholesale & retail | 2020 |
| Site Sentinel Limited | Professional & scientific | 2006 |
| Sivone Retail Limited | Wholesale & retail | 2020 |
| Sizzlers Leamington Spa Ltd | Hospitality | 2024 |
| SJ Mediation Limited | Professional & scientific | 2012 |
| SJB Engineering Services Ltd | Professional & scientific | 2023 |
| SJB Surveying Limited | Professional & scientific | 2019 |
| SJF Design & Consulting Limited | Professional & scientific | 2025 |
| Sjla Solutions Limited | Professional & scientific | 2024 |
| Sjohnson Investments Ltd | Real estate | 2025 |
| SJT Advisors Limited | Professional & scientific | 2025 |
| Skelcher Express Limited | Transport & logistics | 2000 |
| Sketchsmith Ltd | Professional & scientific | 2023 |
| Skid Markz Limited | Arts & recreation | 2025 |
| Skin Haven Limited | Other services | 2023 |
| Skinbox Clinic Ltd | Other services | 2023 |
| Skintech Aesthetics Training Academy Ltd | Other services | 2025 |
| SKJ Investments Limited | Real estate | 2020 |
| Skrc (Design and Build) Limited | Construction | 2024 |
| SKS Legal Consultants Ltd | Professional & scientific | 2021 |