| Shipbrick Limited | Professional & scientific | 2004 |
| Shipra Limited | Wholesale & retail | 2025 |
| Shirley & Sons Services Ltd | Construction | 2024 |
| Shirt Squad Ltd | Information & communication | 2025 |
| Shishok Limited | Hospitality | 2020 |
| Shisholk CIC | Health & social care | 2026 |
| Shiv Shakti 30 Ltd | Wholesale & retail | 2025 |
| Shiva Divine Ltd | Wholesale & retail | 2023 |
| Shivram Properties Limited | Real estate | 2017 |
| Shivrika Appartments Limited | Real estate | 2016 |
| Shivrika Limited | Hospitality | 2003 |
| Shivrika-Holdings Ltd | Professional & scientific | 2013 |
| Shoolin Properties Limited | Real estate | 2022 |
| Shooting Star Technologies Ltd | Information & communication | 2014 |
| Shopello International Ltd | Wholesale & retail | 2024 |
| Shorehams Emporium Ltd | Wholesale & retail | 2013 |
| Shoreline Carpets and Flooring Limited | Wholesale & retail | 2024 |
| Shoshin Way CIC | Education | 2026 |
| Shot Full of Rock Ltd | Information & communication | 2019 |
| Showice Limited | Construction | 2025 |
| Showuptoday Ltd | Construction | 2025 |
| Shreerang Limited | Real estate | 2008 |
| Shruva Ltd | Wholesale & retail | 2026 |
| Siansons Limited | Construction | 2021 |
| Siav Live Ltd | Administrative & support | 2023 |
| Sibcoal Limited | Professional & scientific | 2016 |
| Sicm Transport Ltd | Transport & logistics | 2015 |
| Sidra Medicine Limited | Health & social care | 2024 |
| Sienair Aviation Services Ltd | Professional & scientific | 2023 |
| Sigma Accountants Limited | Professional & scientific | 2008 |
| Signal Computer Systems Ltd | Information & communication | 2012 |
| Signature by Barry Limited | Health & social care | 2023 |
| Signatures R US Ltd | Wholesale & retail | 2025 |
| Signs by Seymour Limited | Manufacturing | 2001 |
| Sigzen Technologies Limited | Information & communication | 2023 |
| Siia Ventures Limited | Wholesale & retail | 2022 |
| Sila Connect Limited | Information & communication | 2017 |
| Silk Investigation Solutions Ltd | Administrative & support | 2021 |
| Silkline IT SYS Consult Ltd | Information & communication | 2025 |
| Silkstays Ltd | Hospitality | 2025 |
| Silkwebs Internet Services Limited | Information & communication | 2001 |
| Silly Goose Productions Ltd | Arts & recreation | 2025 |
| SILVAS76 Limited | Hospitality | 2018 |
| Silver Basket Limited | Wholesale & retail | 2025 |
| Silvesto Ltd | Wholesale & retail | 2021 |
| SIM Builders Limited | Construction | 2025 |
| Simairbustri Ltd | Education | 2018 |
| Simmons Logistics Solutions Ltd | Transport & logistics | 2025 |
| Simon Petrow Tree Services Limited | Administrative & support | 2015 |
| Simon Shaps Limited | Professional & scientific | 2015 |
| Simpharma Ltd | Wholesale & retail | 2025 |
| Simple Car Funding Limited | Administrative & support | 2018 |
| Simply Bliss Beauty Salons Limited | Other services | 2015 |
| Simply Gold Limited | Health & social care | 2022 |
| Simply Refurb Ltd | Real estate | 2024 |
| Simpson & SON Construction Ltd | Manufacturing | 2018 |
| Simra Azad Ltd | Wholesale & retail | 2026 |
| Sinai Sports Ltd | Arts & recreation | 2015 |
| Sinclair Hammelton Limited | Real estate | 2008 |
| Sindher Property Management UK Ltd | Professional & scientific | 2022 |
| Singh Global Investments Limited | Information & communication | 2020 |
| Singh-Judge Property Management Ltd | Real estate | 2021 |
| Singing in the Drains Limited | Water & waste | 2021 |
| Sipher Accounting & Tax Services Ltd | Professional & scientific | 2012 |
| Sipware Ltd | Manufacturing | 2024 |
| Siren Dental Therapy and Aesthetics Limited | Health & social care | 2025 |
| Sirfin Ltd | Construction | 2021 |
| Site-Assist Facilities Limited | Real estate | 1995 |
| Sithy Taxi Ltd | Transport & logistics | 2026 |
| Siva Admin Services Ltd | Administrative & support | 2024 |
| Sivagurunathan Senthamil Agama Gurupeedam Limited | Manufacturing | 2025 |
| Sizzler Piri Piri Ltd | Hospitality | 2018 |
| SJ Apothecary Ltd | Health & social care | 2025 |
| SJ Does Limited | Professional & scientific | 2021 |
| SJ Learning Ltd | Education | 2026 |
| Sj&Sb Limited | Construction | 2025 |
| Sj's Pokéstore Limited | Wholesale & retail | 2026 |
| SJC Distributions Limited | Transport & logistics | 2020 |
| SJC Training Ltd | Professional & scientific | 2011 |
| Sjcvisuals Ltd | Information & communication | 2023 |
| SJL Digital Planning Ltd | Professional & scientific | 2021 |
| SJM Insight Ltd | Professional & scientific | 2025 |
| SK 1792 Holdings Ltd | Financial services | 2024 |
| SK 1792 Ltd | Professional & scientific | 2021 |
| SK Electronic Solutions Ltd | Manufacturing | 2018 |
| SK Logistiq Ltd | Transport & logistics | 2026 |
| SK RE Holdings Limited | Real estate | 2024 |
| SK Surveying Limited | Professional & scientific | 2023 |
| SK Treasury Services Ltd | Professional & scientific | 2024 |
| SK Vehicle Solutions Ltd | Transport & logistics | 2023 |
| Sk's Retail Limited | Wholesale & retail | 2018 |
| SKC Swift Limited | Wholesale & retail | 2026 |
| Sketch Craft Ltd | Information & communication | 2025 |
| Skills N More Limited | Professional & scientific | 2024 |
| Skin by DM Ltd | Other services | 2021 |
| Skoon Travel Ltd | Administrative & support | 2016 |
| SKS IT Consultancy Ltd | Information & communication | 2024 |
| Sky Cars Gatwick Limited | Transport & logistics | 2025 |
| Sky Voice Records Limited | Information & communication | 2021 |
| Skyclear Solutions Ltd | Agriculture & fishing | 2022 |