| Sandelford Limited | Professional & scientific | 2006 |
| Santon Ltd | Real estate | 2024 |
| SAR Films Limited | Information & communication | 2025 |
| Sara Bird Ltd | Other services | 2021 |
| Sarwar Trading Ltd | Wholesale & retail | 2015 |
| Satiad Limited | Information & communication | 2018 |
| Satvik Food Ltd | Hospitality | 2022 |
| Saunders Group Ltd | Construction | 2013 |
| Saxon Investment Properties Ltd | Real estate | 2015 |
| SBH Finance Ltd | Professional & scientific | 2010 |
| Scala Renewables Group Limited | Professional & scientific | 2022 |
| Scimetrics Limited | Financial services | 2023 |
| Second Southfleet Maintenance Limited | Real estate | 1962 |
| Secondary Science Learning Centre Limited | Education | 2018 |
| Seethrough Ltd | Arts & recreation | 2017 |
| Semantic Business Services Ltd | Professional & scientific | 2019 |
| Semoni Group Limited | Professional & scientific | 2019 |
| Senex Property Ltd | Real estate | 2022 |
| Serendib Assets Ltd | Professional & scientific | 2021 |
| Serene Paws Studio Ltd | Other services | 2026 |
| SET UA Limited | Transport & logistics | 2021 |
| SEV Events Limited | Other services | 2016 |
| Seymore Estates Limited | Real estate | 2013 |
| Shady Baby Ltd | Wholesale & retail | 2019 |
| Shakeel Optical Ltd | Health & social care | 2018 |
| Shanembra Partners Limited | Professional & scientific | 2022 |
| Share Type Ltd | Information & communication | 2013 |
| Sharp Clicks Ltd | Professional & scientific | 2017 |
| Shatra Ltd | Construction | 2019 |
| Sheet Roofing Ltd | Construction | 2016 |
| Shield Service Group Limited | Professional & scientific | 1998 |
| Shikha Takeaway Ltd | Hospitality | 2025 |
| Shore Studios Limited | Construction | 2015 |
| Shoreditch 123 Ltd | Extraterritorial | 2014 |
| Shortland Electrical Ltd | Construction | 2023 |
| Shroomstar Ltd | Manufacturing | 2024 |
| Shrubs & Tubs Garden Services Ltd | Administrative & support | 2012 |
| Shrubs & Tubs Limited | Wholesale & retail | 1979 |
| Sigela Limited | Financial services | 2014 |
| Signature Projects (London) Limited | Construction | 2025 |
| Signature Projects (South East) Ltd | Construction | 2020 |
| Silverfox Associates Limited | Professional & scientific | 2011 |
| Silverway Engineering Ltd | Professional & scientific | 2022 |
| Simon Hawkins Futures Limited | Financial services | 1995 |
| Simply Academy Ltd | Information & communication | 2011 |
| Simply Apprenticeships Ltd | Administrative & support | 2013 |
| Simply Know Ltd | Education | 2022 |
| Sirius Plumbing and Heating Ltd | Construction | 2023 |
| SJC Consulting Services Limited | Professional & scientific | 2025 |
| Sketch & Stitch Limited | Wholesale & retail | 2021 |
| SL Ecom Ltd | Wholesale & retail | 2025 |
| SLE Building Refurb Ltd | Construction | 2022 |
| Slomer Limited | Information & communication | 2016 |
| Sl’Ice Global Ltd | Administrative & support | 2025 |
| Small and Cute Ltd | Wholesale & retail | 2023 |
| Smart Bayes Ltd | Information & communication | 2015 |
| Smart Mobility Limited | Transport & logistics | 2017 |
| Smart Plumbing Limited | Construction | 2006 |
| Smart Recovery TS Ltd | Wholesale & retail | 2019 |
| Smart Urban Mobility Solutions Limited | Professional & scientific | 2017 |
| Smita Trivedi Ltd | Health & social care | 2026 |
| Smith and Goat Limited | Other services | 2019 |
| SNR Construction Ltd | Construction | 2018 |
| SO & Co Developments Ltd | Real estate | 2022 |
| SO & Co Maintenance Limited | Construction | 2020 |
| Sofia Marino Limited | Wholesale & retail | 2018 |
| Soios for Business Ltd | Information & communication | 2018 |
| Something Different Catering Ltd | Hospitality | 2020 |
| SON Takeaway Limited | Hospitality | 2022 |
| Sorrellis Ltd | Information & communication | 2023 |
| Soular Space Ltd | Other services | 2024 |
| South East Painting Decorating Ltd | Construction | 2025 |
| Spearhead Technology Limited | Information & communication | 2006 |
| Specialised Hire Solutions Ltd | Other services | 2012 |
| Specs & Sight Ltd | Wholesale & retail | 2026 |
| Spectrum Line Limited | Transport & logistics | 2025 |
| Spencer Craig Partnership Limited | Real estate | 2005 |
| Spinaq Services Limited | Professional & scientific | 2026 |
| Spiritz Limited | Wholesale & retail | 2019 |
| Splashlime Ltd | Information & communication | 2011 |
| Sporting Profiles (2025) Ltd | Wholesale & retail | 2025 |
| Sporting Profiles Limited | Wholesale & retail | 2008 |
| Spray Pals Ltd | Wholesale & retail | 2026 |
| Springbank Electrical Services Ltd | Construction | 2008 |
| Spurriers Farm Management Company Ltd | Households | 2008 |
| Square Mile London Ltd | Transport & logistics | 2014 |
| Srilimbadriproperties Limited | Real estate | 2025 |
| SS Beauty & Aesthetics London Ltd | Other services | 2025 |
| SS Engineering PVT Limited | Professional & scientific | 2014 |
| SS Fixing Ltd | Construction | 2020 |
| ST Matthews Financial Services Ltd | Financial services | 2020 |
| Stage One Parties Limited | Arts & recreation | 2015 |
| Stage One Theatre School Ltd | Arts & recreation | 2007 |
| Staka & Sons Ltd | Construction | 2024 |
| Stakd Burger Ltd | Hospitality | 2024 |
| STANFIELD1 Limited | Construction | 2016 |
| Stanley Rose Associates Limited | Professional & scientific | 2024 |
| Stanley Rose Audit Services Limited | Professional & scientific | 2022 |
| Stanley Rose Payroll Services Limited | Information & communication | 2025 |
| Stanley Rose Probate Services Limited | Professional & scientific | 2025 |