| Surya Real Estate Group Ltd | Real estate | 2024 |
| Sushi Express London Limited | Administrative & support | 2014 |
| Suso Removal Ltd | Transport & logistics | 2025 |
| Sussex Place (Slough) Management Company Limited | Other services | 1984 |
| Sustain & Able Limited | Information & communication | 2017 |
| Sustainable Energy Centre Limited | Manufacturing | 2016 |
| Sustane Properties Ltd | Construction | 2024 |
| Suthar Creative Ltd | Information & communication | 2017 |
| Sutherland IFA Limited | Financial services | 2012 |
| Sutherlands Holdings Ltd | Real estate | 2019 |
| Sutton and Banaczek Property Investments Limited | Real estate | 2021 |
| Sutton House Property Limited | Real estate | 2016 |
| Sutton Minor Properties Ltd | Real estate | 2025 |
| Suva Water Limited | Wholesale & retail | 2025 |
| Suvrentals Ltd | Professional & scientific | 2026 |
| Svan Homes Ltd | Construction | 2026 |
| Svelto Ltd | Wholesale & retail | 2025 |
| Svetovid Ltd | Professional & scientific | 2026 |
| SVI JM Property Ltd | Real estate | 2024 |
| SVI Property Ltd | Real estate | 2022 |
| SVI Solutions Ltd | Information & communication | 2017 |
| Svish Consulting Limited | Information & communication | 2013 |
| Svtnc Services Ltd | Information & communication | 2017 |
| SVV Limited | Information & communication | 2010 |
| SVV Properties Ltd | Real estate | 2019 |
| Swag Enterprises Ltd | Construction | 2019 |
| Swagath Ltd | Hospitality | 2025 |
| Swaich Home Developments Ltd | Construction | 2024 |
| Swami Hair Salon Limited | Other services | 2026 |
| Swann Secure Limited | Other services | 2015 |
| Swap Byte Ltd | Information & communication | 2024 |
| Swapna Picture Company Ltd | Information & communication | 2026 |
| Swash Tech Ltd. | Information & communication | 2014 |
| Sweep Limited | Other services | 2018 |
| Sweet Bonds Forever Ltd | Wholesale & retail | 2025 |
| Sweet Property Estates Limited | Real estate | 2025 |
| Sweet Pulses Ltd | Manufacturing | 2020 |
| Sweet Rush Ltd | Wholesale & retail | 2026 |
| Sweet Treats by Sukh Ltd | Manufacturing | 2021 |
| Sweetest Affair Limited | Administrative & support | 2017 |
| Swift Car Sales Swindon Ltd | Wholesale & retail | 2026 |
| Swift Courier Services Ltd | Transport & logistics | 2016 |
| Swift Express Ltd | Transport & logistics | 2020 |
| Swift Express Trading Ltd | Wholesale & retail | 2023 |
| Swift Freight Limited | Transport & logistics | 2020 |
| Swift London Roofing and Building Ltd | Construction | 2014 |
| Swift Manors Ltd | Real estate | 2025 |
| Swift Mindcraft Limited | Health & social care | 2022 |
| Swift Ryde Ltd | Transport & logistics | 2024 |
| Swift Task Ltd | Wholesale & retail | 2019 |
| Swift Traders Inc Limited | Wholesale & retail | 2025 |
| SWIFT2PASS Limited | Education | 2026 |
| Swiftex-Deliverix Limited | Professional & scientific | 2025 |
| Swiftfix Auto Ltd | Wholesale & retail | 2025 |
| Swiftpoint PVT Ltd | Transport & logistics | 2025 |
| Swiftsource Trading Ltd | Wholesale & retail | 2026 |
| Swiftstock Wholesale Ltd | Wholesale & retail | 2025 |
| Swiftwind Consulting Limited | Information & communication | 2010 |
| Swindon Chamber of Commerce | Other services | 2008 |
| Swiss Associates Limited | Other services | 2013 |
| Swiss Gold London Ltd | Other services | 2023 |
| Swits Ltd | Information & communication | 2016 |
| Swiz Ltd | Wholesale & retail | 2025 |
| SWJ Homes Ltd | Real estate | 2023 |
| Swordfish Locomotive Services Ltd | Wholesale & retail | 2022 |
| SX Construction Ltd | Construction | 2018 |
| SX Developments Ltd | Real estate | 2024 |
| SXO Ltd | Real estate | 2025 |
| SXO Property Advisory Ltd | Construction | 2019 |
| Syam First Ltd | Transport & logistics | 2022 |
| Syan Management Company Limited | Health & social care | 2025 |
| Sydney Community Project Ltd | Extraterritorial | 2012 |
| Syed Akbar ALI Limited | Wholesale & retail | 2025 |
| Syed Estates Ltd | Real estate | 2017 |
| Syed Medics Ltd | Health & social care | 2021 |
| Syed Transport Ltd | Other services | 2023 |
| Syeda Mirha Limited | Wholesale & retail | 2024 |
| Sykes Developments Ltd | Real estate | 2022 |
| Sykes Fabrication Limited | Manufacturing | 2018 |
| Sykes London Shopfronts Ltd | Construction | 2023 |
| Sykes Shopfitters Limited | Construction | 2013 |
| Syln Business Systems Limited | Information & communication | 2013 |
| Syln Property Investments Limited | Real estate | 2025 |
| Syloq Limited | Information & communication | 2026 |
| Symbioptic Ltd | Wholesale & retail | 2023 |
| Symiz Limited | Wholesale & retail | 2021 |
| Symt Limited | Information & communication | 2016 |
| Symtech Services Limited | Construction | 2024 |
| Sync UP Limited | Information & communication | 2024 |
| Syndicate Developers Ltd | Real estate | 2019 |
| Syndicate Haulage Ltd | Transport & logistics | 2024 |
| Synergific FZC Ltd | Manufacturing | 2023 |
| Synergy (London) Limited | Information & communication | 2022 |
| Synergy Advisory Ltd | Professional & scientific | 2022 |
| Synergy Cars Limited | Transport & logistics | 2009 |
| Synergy Recycling Ltd | Water & waste | 2022 |
| Synoent Limited | Wholesale & retail | 2023 |
| Syplan Ltd | Professional & scientific | 1999 |
| SYS Facility Management Ltd | Administrative & support | 2025 |
| Sysflow Ltd | Information & communication | 2025 |