| Solve IG Solutions Ltd | Professional & scientific | 2013 |
| Solven Brooks Ltd | Wholesale & retail | 2025 |
| SOM Projects UK Limited | Real estate | 2021 |
| Soma Consulting Limited | Information & communication | 2014 |
| Somal Properties Limited | Real estate | 2006 |
| Somearth Realtors Limited | Real estate | 2006 |
| Somerton Gardens Cricklewood Limited | Households | 1998 |
| Sometal Limited | Water & waste | 2022 |
| Somji Ltd | Health & social care | 2015 |
| Sonas Beauty Ltd | Other services | 2021 |
| Soneji Studios Ltd | Real estate | 2020 |
| Songul Csonka Consulting Ltd | Information & communication | 2025 |
| Soni Mandair Law Ltd | Professional & scientific | 2022 |
| Soni Real Estates Ltd | Real estate | 2021 |
| Sonic Builders Limited | Construction | 2017 |
| Sonicount Limited | Administrative & support | 2024 |
| Sonnenbear Ltd | Professional & scientific | 2013 |
| Sonny & Rubys Limited | Hospitality | 2026 |
| Sono IT LP | | 2017 |
| Sons of BW Limited | Administrative & support | 2016 |
| Sons of Carpentry Ltd | Manufacturing | 2026 |
| Sons of Earth Ltd | Administrative & support | 2024 |
| Sonteri Limited | Wholesale & retail | 2019 |
| Soorena LP | | 2017 |
| Sophias Kitchen Ltd | Hospitality | 2023 |
| Sophisticated Savers Ltd | Information & communication | 2017 |
| Sophos Advisors Limited | Professional & scientific | 2010 |
| Soraya Studio Ltd | Professional & scientific | 2025 |
| SOS Financial Ltd | Professional & scientific | 2025 |
| Sosafe Security Limited | Information & communication | 2022 |
| Sote Canteen Ltd | Hospitality | 2018 |
| Soufriere Consulting Ltd | Professional & scientific | 2022 |
| Soul Survivor | Other services | 2000 |
| Soul Survivor Trading Limited | Wholesale & retail | 1994 |
| Soulart Limited | Manufacturing | 2024 |
| Souldern Ltd | Real estate | 2021 |
| Soumi Mitra Limited | Real estate | 2018 |
| Soun Enterprise Ltd | Health & social care | 2013 |
| Sound Creative AM Ltd | Education | 2026 |
| Sound Gurus Limited | Wholesale & retail | 2008 |
| Soundplay Holdings Limited | Financial services | 2019 |
| Soundplay International Limited | Other services | 2019 |
| Soundplay Music Limited | Education | 2013 |
| Soundwalkers Ltd | Professional & scientific | 2015 |
| Source Merchandising Limited | Professional & scientific | 2017 |
| Sous Limited | Information & communication | 2000 |
| Sousou Connect Limited | Financial services | 2015 |
| South African Foods Limited | Wholesale & retail | 2008 |
| South Beach Digital Ltd | Real estate | 2020 |
| South Beach Lettings Ltd | Real estate | 2025 |
| South North Properties Limited | Real estate | 2013 |
| South Oxhey Cafe 26 Ltd | Hospitality | 2026 |
| Southend Property Investment Limited | Real estate | 2022 |
| Southend Restaurant Limited | Hospitality | 2023 |
| Southern Airways Limited | Administrative & support | 1939 |
| Southern Aluminium and Upvc Window Company (London) Limited | Construction | 1981 |
| Southern Heights Ltd | Construction | 2025 |
| Southgrove Flooring Ltd | Construction | 2024 |
| Southgrove Group Ltd | Financial services | 2024 |
| Southgrove Painting Contractors Limited | Construction | 1977 |
| Southmoore Limited | Real estate | 2021 |
| Southwark Management Ltd | Construction | 2022 |
| Southwell Gardens (Conversions) Company Limited | Households | 1999 |
| Sova Media Ltd | Information & communication | 2016 |
| Sovereign London Properties Ltd | Real estate | 2024 |
| Sovereign Wealth Investments Limited | Real estate | 2021 |
| Sovereign Wellbeing Ltd | Professional & scientific | 2025 |
| Sovereignx Limited | Real estate | 2023 |
| Sowan Builders Ltd | Construction | 2024 |
| SP Accounting & Consulting Ltd | Professional & scientific | 2009 |
| SP Creative Ltd | Professional & scientific | 2025 |
| SP Greens Ltd | Information & communication | 2025 |
| SP Grocery Limited | Wholesale & retail | 2024 |
| SP Tech Ltd | Information & communication | 2024 |
| SP2020 Associates Limited | Professional & scientific | 2026 |
| Spa Private Limited | Wholesale & retail | 2025 |
| Space Associates Limited | Other services | 1999 |
| Space Bridge Properties Limited | Real estate | 2020 |
| Space by the Day Limited | Real estate | 2022 |
| Space Five Creative Limited | Information & communication | 2017 |
| Spade Investments Limited | Real estate | 2018 |
| Spag Holdings Ltd | Construction | 2024 |
| Spain and France Accountants Ltd | Professional & scientific | 2018 |
| Span Services Ltd | Professional & scientific | 2023 |
| Spar Medicare Limited | Health & social care | 2015 |
| Sparetech Solutions Limited | Wholesale & retail | 2025 |
| Sparkbudd Technologies Inc Ltd | Information & communication | 2026 |
| Sparking Success Ltd | Health & social care | 2025 |
| Sparklabs Electronics Limited | Wholesale & retail | 2025 |
| Sparkle Girls Limited | Administrative & support | 2022 |
| Sparkle Works Ltd | Administrative & support | 2021 |
| Sparkling Residence Ltd | Construction | 2019 |
| Sparkling Stars Day Nursery and Preschool Ltd | Education | 2026 |
| Sparks E-Cigarettes Limited | Wholesale & retail | 2013 |
| Sparks Three Ltd | Professional & scientific | 2020 |
| Sparksaver Ltd | Wholesale & retail | 2024 |
| Sparksphere Consulting Ltd | Information & communication | 2025 |
| Sparktrizity London Ltd | Construction | 2019 |
| Sparkwave Services Ltd | Administrative & support | 2018 |
| Sparky Squirrel Ltd | Professional & scientific | 2023 |