| Sardana Medical Services Ltd | Health & social care | 2015 |
| Saree Hire Store Limited | Wholesale & retail | 2022 |
| Saris of London Ltd | Wholesale & retail | 2013 |
| Sartoux Group Limited | Administrative & support | 2019 |
| Sarya Foods Ltd | Wholesale & retail | 2018 |
| SAS Safety Limited | Professional & scientific | 2026 |
| Sasha Scott Limited | Professional & scientific | 2010 |
| Sashedit Ltd | Manufacturing | 2022 |
| Satori Intelligence Ltd | Administrative & support | 2025 |
| Sats UK Group Limited | Health & social care | 2006 |
| Saturday 3PM Ltd | Wholesale & retail | 2017 |
| Sausage Accounts Ltd | Professional & scientific | 2024 |
| SAV Associates Ltd | Wholesale & retail | 2011 |
| Savage Investment Property Limited | Real estate | 2007 |
| Savani Newsagent Limited | Wholesale & retail | 2018 |
| Sawang Limited | Real estate | 2000 |
| Sawczyn Design Limited | Administrative & support | 2001 |
| Sawyers (Sussex) Limited | Administrative & support | 2005 |
| Saxby Management Services Ltd | Construction | 2024 |
| Saxon County Estates Limited | Real estate | 2002 |
| Saynada Limited | Real estate | 2016 |
| Saywell International Limited | Transport & logistics | 1957 |
| Sbhg Property Ltd | Households | 2022 |
| SBJ Ltd | Information & communication | 2021 |
| SBX Investments Limited | Financial services | 2024 |
| SBX Partners LLP | | 2024 |
| SBX Ventures Limited | Administrative & support | 2015 |
| SC Exports Limited | Wholesale & retail | 2024 |
| SC International Holding Limited | Financial services | 2020 |
| SC Strategy Consultants Ltd | Professional & scientific | 2022 |
| Scaffguard Limited | Administrative & support | 2000 |
| Scalecross Limited | Professional & scientific | 2026 |
| Scampi & Frites Studios Ltd | Information & communication | 2025 |
| Scandi Beach Properties LLP | | 2025 |
| Scannex Electronics Limited | Manufacturing | 1978 |
| Scarnish Holdings Limited | Real estate | 2015 |
| Scarth Baker Ltd | Administrative & support | 2016 |
| Scawen Ltd | Professional & scientific | 2023 |
| Scaws Limited | Information & communication | 2016 |
| SCC Agency Limited | Health & social care | 2012 |
| Scdc Property Ltd | Real estate | 2021 |
| SCE Investments Ltd | Real estate | 2020 |
| Scene Group Limited | Information & communication | 2019 |
| Scent Retail Ltd | Wholesale & retail | 2009 |
| SCH Consultancy Services Ltd | Administrative & support | 2025 |
| School Apps Ltd | Information & communication | 2011 |
| Science Media Studio Ltd | Information & communication | 2012 |
| Scientaria Ltd | Information & communication | 2024 |
| Scofi Plumbing & Heating Limited | Construction | 2020 |
| Scorpio Digital Group Ltd | Professional & scientific | 2025 |
| Scott Baker Properties Ltd | Real estate | 2017 |
| Scott Bourne Commercials Ltd | Professional & scientific | 2026 |
| Scott's Autocare Limited | Wholesale & retail | 2017 |
| Scramblewood Ltd | Information & communication | 2016 |
| Screed Systems Ltd | Construction | 2011 |
| Sculpt & Reform Limited | Arts & recreation | 2025 |
| Sculpt Lifestyle Ltd | Education | 2025 |
| Sculpting Serenity Limited | Wholesale & retail | 2024 |
| SDE Development Solutions Ltd | Professional & scientific | 2020 |
| SDH Builders (Essex) Limited | Construction | 2019 |
| SDJ08 Ltd | Information & communication | 2019 |
| SDR Construction and Consultancy Ltd | Construction | 2025 |
| SDS Building Ltd | Construction | 2018 |
| SDW Landscapes Limited | Construction | 2015 |
| SE Resources Ltd | Real estate | 2023 |
| Sea Aggregates Limited | Extraterritorial | 1985 |
| Sea Colours Ltd | Real estate | 2011 |
| Seaborne Plastics Limited | Manufacturing | 1994 |
| Seabrook House Limited | Health & social care | 2005 |
| Seabrook House Support Services Limited | Health & social care | 2012 |
| Seacroft Freeholders Ltd | Households | 2026 |
| Seagull GIN Ltd | Hospitality | 2017 |
| Seagull RUM Ltd | Hospitality | 2017 |
| Seagull Spirits Ltd | Hospitality | 2019 |
| Seal Roofing Services Limited | Construction | 2019 |
| Sealand Systems Ltd | Information & communication | 1999 |
| Seascape Holdings Limited | Households | 2017 |
| Seaside Creative Ltd | Professional & scientific | 2017 |
| Seaside House Management Ltd | Real estate | 2022 |
| Seasider Films Ltd | Information & communication | 2019 |
| Seatown Accountancy Services Ltd | Professional & scientific | 2018 |
| Seaview Roofing Limited | Construction | 2023 |
| Seaweed GUY CIC | Agriculture & fishing | 2025 |
| Seawhite of Brighton Limited | Wholesale & retail | 1972 |
| Seb.Ly Limited | Information & communication | 2015 |
| Sebastian Bergne Ltd | Professional & scientific | 2003 |
| Sebastien Hinault Limited | Construction | 2021 |
| Sebata Ltd | Real estate | 2017 |
| Second Term Limited | Hospitality | 1996 |
| Secret Rare Ltd | Financial services | 2020 |
| Sector Media Ltd | Information & communication | 2024 |
| Secure Sale Limited | Real estate | 2016 |
| Secured Appliance Limited | Manufacturing | 2026 |
| Securipay Limited | Administrative & support | 2026 |
| Seda Aerospace Limited | Wholesale & retail | 2025 |
| SEE More Projects Ltd | Information & communication | 2014 |
| SEE More Solutions Ltd | Professional & scientific | 2024 |
| Seeachange Ltd | Professional & scientific | 2015 |
| Seedthink Technologies Ltd | Information & communication | 2026 |
| Seeko International Ltd | Wholesale & retail | 2006 |