| S.I.G Zenith Ltd | Real estate | 2024 |
| S.Jkerbrace Ltd | Manufacturing | 2024 |
| S.P. Tirtu Logistic Ltd | Transport & logistics | 2021 |
| Sacred Sound Healing Arts Centre | Health & social care | 2016 |
| Saddle Snack Co Ltd | Manufacturing | 2024 |
| Safe Skills Training Ltd | Education | 2025 |
| Safe Styling Home Improvements Limited | Construction | 2018 |
| Safeli Limited | Professional & scientific | 2025 |
| Safestyling Home Improvements & Sons Ltd | Construction | 2021 |
| Safety Conscious Limited | Administrative & support | 2004 |
| Safety in Business Limited | Professional & scientific | 1999 |
| SAJ Mills Properties Ltd | Real estate | 2022 |
| Saje Associates Ltd | Professional & scientific | 2025 |
| Sales Force Online Limited | Wholesale & retail | 2025 |
| Sally Mitchell Fine Arts Limited | Administrative & support | 2005 |
| Salt & Light Financial Services Limited | Financial services | 2019 |
| Samantha Davis Estates Ltd | Real estate | 2025 |
| Samjas Consulting Limited | Agriculture & fishing | 2013 |
| Sammac Limited | Construction | 2025 |
| Sams (Midlands) Ltd | Wholesale & retail | 2025 |
| Samuel Bates (Northampton) Limited | Extraterritorial | 1942 |
| Sanders Environmental H&S Services Limited | Information & communication | 2022 |
| Sandicroft Stud Ltd | Agriculture & fishing | 2026 |
| SANDIRON20 Limited | Real estate | 2018 |
| Sandstone Consulting Limited | Professional & scientific | 2018 |
| Sanfran Management Ltd Ltd | Professional & scientific | 2026 |
| Sankate Homes Limited | Construction | 2004 |
| Sanquhar House Consultancy Limited | Professional & scientific | 2019 |
| Sapphire Financial Management Ltd | Financial services | 2015 |
| Sarah Allen Limited | Financial services | 2021 |
| Sarah Cameron Consulting Limited | Other services | 2011 |
| Sarah COX Cars Limited | Wholesale & retail | 2007 |
| Sarcoid Surgery Limited | Professional & scientific | 2015 |
| Sasevmo Ltd | Real estate | 2011 |
| Satoru Systems Ltd | Extraterritorial | 2021 |
| Saturn Dynamics Inc. | | 2025 |
| Savage Facilities Limited | Construction | 2026 |
| Savage Plant (Newark) Ltd | Administrative & support | 2025 |
| Savams Construction Ltd | Construction | 2017 |
| Savams Holdings Limited | Financial services | 2025 |
| Savile House Properties Limited | Real estate | 1997 |
| Savoir Faire International Limited | Extraterritorial | 1988 |
| SAY Dolphin Ltd | Wholesale & retail | 2022 |
| SBF Solutions Limited | Information & communication | 2010 |
| SBS Building & Joinery Ltd | Construction | 2017 |
| Scatterbash Ltd | Information & communication | 2007 |
| SCB Auditing, Food Safety Training , Consultant Limited | Professional & scientific | 2025 |
| Scdh Ltd | Information & communication | 2026 |
| Scentual World Limited | Wholesale & retail | 2006 |
| Sceptre IT Services Ltd | Professional & scientific | 2023 |
| Schpling Ltd | Households | 2019 |
| Schplong Limited | Real estate | 2020 |
| Science Machine Inc. | | 2024 |
| Scotswood Chemicals Ltd | Wholesale & retail | 2018 |
| Scrap Buyers R US Limited | Wholesale & retail | 2023 |
| Scrumpy Wasp Limited | Manufacturing | 2011 |
| SDCD5657 | Financial services | 2016 |
| SDF Roofing Ltd | Construction | 2012 |
| Sea Blocks Management Limited | Households | 2000 |
| Secure Infotech Ltd | Information & communication | 2015 |
| Secure Logistics Services Limited | Administrative & support | 2015 |
| Security Advisory Services Limited | Information & communication | 2024 |
| Seda Steelwork Engineering Limited | Manufacturing | 2015 |
| Sedgecom Limited | Wholesale & retail | 2024 |
| Sedgefield Court Management Company Limited | Households | 1990 |
| SEE Greene Limited | Manufacturing | 2018 |
| Seed. Collaborative Ltd | Professional & scientific | 2024 |
| Seeds Express Limited | Agriculture & fishing | 1993 |
| Seek & Hire Ltd | Administrative & support | 2024 |
| Seeler Ltd | Other services | 2020 |
| Seema Finance Limited | Professional & scientific | 2007 |
| Select Home Improvements Ltd | Construction | 2023 |
| Select Travel Solutions Limited | Administrative & support | 2016 |
| Sellars Earthworks Limited | Construction | 2016 |
| Sempre Music Ltd | Wholesale & retail | 2023 |
| Senpai Solutions Limited | Information & communication | 2020 |
| Sentiment 360 Ltd | Information & communication | 2013 |
| SEP Solutions Limited | Information & communication | 2002 |
| Sergison Holdings Limited | Hospitality | 2019 |
| Servatec Holdings Limited | Mining & quarrying | 2020 |
| SES Engineering (Newark) Ltd | Manufacturing | 2018 |
| Seventy Seven Company Holdings Limited | Financial services | 2022 |
| Seventy Seven Company Limited | Wholesale & retail | 2001 |
| SF Construction & Roofing Ltd | Construction | 2023 |
| SH Gardens & Driveways Limited | Administrative & support | 2021 |
| Shablam on Sundays Ltd | Arts & recreation | 2024 |
| Shade Health Solutions Limited | Health & social care | 2014 |
| Shamanic Earth Ltd | Manufacturing | 2023 |
| Shambo Roofing Ltd | Construction | 2026 |
| Shane's Waste Ltd | Wholesale & retail | 2023 |
| Shangri LA Chinese Restaurant Ltd | Hospitality | 2011 |
| Shanry Windfarm Limited | Energy | 2013 |
| Shaping Futures Limited | Education | 2001 |
| Sharlotte Consulting Services Limited | Information & communication | 2012 |
| Sharnbrook Investments Limited | Hospitality | 2018 |
| Sharpe Meica Solutions Ltd | Manufacturing | 2021 |
| Sharptec Ltd | Professional & scientific | 2014 |
| Shayleigh Express Courier Limited | Transport & logistics | 2021 |
| SHE Leisure Limited | Arts & recreation | 1998 |
| Shed Contract Services Limited | Other services | 2014 |