| Saunasupply Ltd | Wholesale & retail | 2023 |
| Saunders Says Ltd | Information & communication | 2015 |
| Savage Music Nigeria (UK) Ltd | Arts & recreation | 2023 |
| Savage Rose House Ltd | Wholesale & retail | 2025 |
| Save OUR Shutter Ltd | Manufacturing | 2019 |
| Savista Investments Limited | Real estate | 2017 |
| Savoir Aesthetics Limited | Health & social care | 2023 |
| Savoy Laboratories (International) Limited | Manufacturing | 1965 |
| Savvy Letting Ltd | Real estate | 2024 |
| Sawyers Church | Other services | 2010 |
| Saxonhurst Limited | Real estate | 2003 |
| Sayal Ltd | Professional & scientific | 2010 |
| SBA Reworks Ltd | Administrative & support | 2018 |
| SBI Consultancy Limited | Professional & scientific | 2009 |
| SBP Realisations Limited | Wholesale & retail | 2002 |
| SBS Essex Ltd | Professional & scientific | 2025 |
| SC Digital Ltd | Other services | 2025 |
| SC Vending Limited | Other services | 2021 |
| Sc&W Ltd | Professional & scientific | 2017 |
| Scale Point Marketing Ltd | Professional & scientific | 2025 |
| Scalexa Ltd | Information & communication | 2016 |
| Scarbella Ltd | Administrative & support | 2021 |
| Scarlett Consulting Ltd | Professional & scientific | 2019 |
| Sceats Coal Report Ltd | Professional & scientific | 2023 |
| SCF Talent Ltd | Administrative & support | 2025 |
| SCG Group Limited | Other services | 2019 |
| SCH Accounting Services Limited | Financial services | 2006 |
| School's Offices Services Limited | Administrative & support | 2003 |
| Schuller Inc Limited | Other services | 2013 |
| Sci-Fi Warehouse Direct Limited | Wholesale & retail | 1998 |
| Scicona Consultants Ltd | Professional & scientific | 2011 |
| Scope Interiors Limited | Professional & scientific | 2004 |
| Scotch Smoked Salmon Co. Ltd. | Other services | 1994 |
| Scotch Smoked Salmon London Ltd | Wholesale & retail | 2018 |
| Scotscape Group Limited | Administrative & support | 2008 |
| Scotscape Maintenance Ltd | Other services | 2014 |
| Scott - Osborn Limited | Construction | 1985 |
| Scott City Residential Limited | Real estate | 2002 |
| Scott Hamer Limited | Education | 2012 |
| Scott Harris Limited | Hospitality | 1996 |
| Scott Learning & Leadership Consulting Limited | Wholesale & retail | 2025 |
| Scott Lyon Limited | Information & communication | 2010 |
| Scott Merrick LLP | | 2007 |
| Scott's of Southend Ltd | Hospitality | 2002 |
| Scrapshop Ltd | Wholesale & retail | 2024 |
| Screw Loose Transport & Customs Limited | Wholesale & retail | 2025 |
| Scribbly Goose Limited | Arts & recreation | 2019 |
| Scrub and Shine Ltd | Administrative & support | 2013 |
| Sculpt & Enhance Skin & Body Clinic Ltd | Other services | 2025 |
| Sculpt & Glow Academy Ltd Ltd | Other services | 2025 |
| Sculpt and Glow Ltd | Other services | 2025 |
| SCW Financial Services Ltd | Financial services | 2020 |
| SD Electrics Limited | Construction | 2018 |
| SD Holdco Ltd | Financial services | 2022 |
| SD Welding and Fabrication Ltd | Professional & scientific | 2018 |
| SDB Solutions Ltd | Information & communication | 2014 |
| SDM Glazing Ltd | Construction | 2016 |
| Sdmc 1 Limited | Real estate | 2019 |
| SDMC1 Holdings Limited | Financial services | 2022 |
| SDP Enterprises Limited | Real estate | 2019 |
| SE7ENTEEN Limited | Professional & scientific | 2015 |
| Sea to Sand Limited | Wholesale & retail | 2024 |
| SEA2804 Ltd | Transport & logistics | 2025 |
| Seaboure Ltd | Professional & scientific | 2026 |
| Seager Vision Limited | Information & communication | 2006 |
| Sealtec Services Limited | Construction | 2015 |
| Sean Farrelly Limited | Transport & logistics | 2015 |
| Searle's Building Contractors Ltd | Construction | 2024 |
| Sears Trading Limited | Professional & scientific | 2010 |
| Seax Trust | Education | 2011 |
| Seaxe Contract Services Ltd | Other services | 2012 |
| Sebs Associates Limited | Arts & recreation | 2022 |
| Second Mile Consulting Ltd | Professional & scientific | 2017 |
| Secret Innovation Ltd | Wholesale & retail | 2012 |
| Secure Financial Limited | Professional & scientific | 2001 |
| Secure Locking Solutions Limited | Manufacturing | 2013 |
| Seddon Investment Group Ltd | Administrative & support | 2018 |
| Seddon Property Assets Ltd | Real estate | 2017 |
| SEE More Lighting Service Engineering Ltd | Construction | 2009 |
| Seek OUT Lebanese Ltd | Hospitality | 2025 |
| Sefa Catering Limited | Hospitality | 2023 |
| Segment Investments Ltd | Hospitality | 2020 |
| Sejr Limited | Manufacturing | 2023 |
| Seldon Investments Ltd | Financial services | 2018 |
| Select Care Ltd | Public administration | 2025 |
| Select Care Recruitment Ltd | Health & social care | 2023 |
| Select Integrated Business Limited | Professional & scientific | 2005 |
| Selection Logistics Ltd | Transport & logistics | 2025 |
| Selfcare Nation Limited | Health & social care | 2015 |
| Selfgrowth CIC | Agriculture & fishing | 2024 |
| Selkam Services Ltd | Construction | 2018 |
| Sellcycle Limited | Wholesale & retail | 2025 |
| Selman House Investments Limited | Real estate | 2024 |
| Semam Limited | Construction | 2020 |
| Sendtek Limited | Professional & scientific | 2024 |
| Sensapeel Ltd | Manufacturing | 2013 |
| Sentra Group Limited | Administrative & support | 2022 |
| Sentra Solutions Limited | Administrative & support | 2014 |
| Serce Kebab Ltd | Hospitality | 2024 |
| Serene Birthright Ltd | Education | 2017 |