| SA Ophthalmology Limited | Health & social care | 2023 |
| SA Sports Ltd | Education | 2025 |
| Sackville Donald Limited | Professional & scientific | 2011 |
| Safe Sport International | Professional & scientific | 2016 |
| Safeguard Asset Investments Limited | Real estate | 2024 |
| Safeguard Monitoring Limited | Extraterritorial | 2024 |
| Safeguard Security Group Limited | Financial services | 2024 |
| Safeguard Security Systems Ltd | Administrative & support | 2016 |
| Safetonet HB Limited | Information & communication | 2024 |
| Safetonet U.K. Limited | Professional & scientific | 2014 |
| Safety Power Group Limited | Manufacturing | 1988 |
| Sage Film Production Ltd | Information & communication | 2019 |
| Sagrado Drinks Ltd | Wholesale & retail | 2024 |
| Saiph Communications Limited | Information & communication | 2003 |
| Saiph Group Ltd | Financial services | 2008 |
| SAK Global Limited | Other services | 2019 |
| Sakura Finetek UK Limited | Administrative & support | 2008 |
| Salazar Portfolio & Projects Limited | Extraterritorial | 2016 |
| Salazar Projects Limited | Professional & scientific | 2025 |
| Salema Begum Limited | Hospitality | 2019 |
| Salinity UK Limited | Professional & scientific | 1995 |
| Sally Henson Architects Ltd | Professional & scientific | 2025 |
| Sally Murray Travel Ltd | Administrative & support | 2022 |
| Salokh Info Limited | Information & communication | 2013 |
| SAM Digital Ltd | Information & communication | 2026 |
| SAM24 Ltd | Transport & logistics | 2022 |
| SAM777 Limited | Wholesale & retail | 2023 |
| Sami Consulting Ltd. | Professional & scientific | 1999 |
| Samreen Consulting UK Limited | Professional & scientific | 2025 |
| Samsung LEE 168 & Co Ltd | Real estate | 2025 |
| SAN Martin Limited | Administrative & support | 2017 |
| Sand Dragon Ltd | Information & communication | 2023 |
| Sanders Sports Safety Limited | Health & social care | 2008 |
| Sandhill Racing Limited | Arts & recreation | 2002 |
| Sandleford Farm Residents Ltd | Real estate | 2018 |
| Sandleford Holdings (UK) Ltd | Wholesale & retail | 2016 |
| Sapertransport Limited | Transport & logistics | 2025 |
| Sapienter Wealth Management Consultancy Limited | Extraterritorial | 2015 |
| Sapphire Club Ltd | Hospitality | 2019 |
| Sapt Properties Limited | Real estate | 2022 |
| Sapt Technology and Consultancy Services Ltd | Information & communication | 2021 |
| Sarah Bradden Ltd | Health & social care | 2017 |
| Sarah Dunnett Consulting Limited | Other services | 2017 |
| Sarah Neary Freelancing Ltd | Professional & scientific | 2022 |
| Sarah Training Ltd | Information & communication | 2019 |
| Sarastone Limited | Professional & scientific | 1983 |
| Sarosol Limited | Professional & scientific | 2012 |
| Saskime Limited | Real estate | 2025 |
| Satguru Properties Ltd | Real estate | 2022 |
| Savage House Limited | Information & communication | 2021 |
| SB & SB Holdings Limited | Financial services | 2024 |
| SB Electrical Contracting Limited | Construction | 2025 |
| SB Window Cleaning Ltd | Administrative & support | 2023 |
| Sbose Consultants Ltd | Information & communication | 2018 |
| Sbrc Holdings Ltd | Financial services | 2023 |
| Scanner Express Limited | Wholesale & retail | 2009 |
| Scarborough 2021 Ltd | Professional & scientific | 2021 |
| Schom.Com Ltd | Professional & scientific | 2005 |
| Scofell Landscapes Limited | Administrative & support | 2004 |
| Scoop Patrol Ltd | Water & waste | 2025 |
| Scorching Bay Ltd | Professional & scientific | 2007 |
| Scott Paul Electrical Contractors Ltd | Construction | 2023 |
| Scott Talbot Mortgages Limited | Financial services | 2025 |
| SCOTT2B Ltd | Manufacturing | 2020 |
| Scrivenerproperties Limited | Construction | 2026 |
| Scrolllytics Ltd | Information & communication | 2025 |
| Scruffy Coder Limited | Information & communication | 2022 |
| SDD Real Estates Ltd | Real estate | 2024 |
| Sdjay Limited | Real estate | 2025 |
| SDK AI Limited | Professional & scientific | 2020 |
| Sdml Limited | Wholesale & retail | 1999 |
| Sdplets Ltd | Real estate | 2021 |
| Seachester Three Limited | Extraterritorial | 2013 |
| Sealus Ltd | Construction | 2022 |
| Seamless Integration Ltd | Construction | 2017 |
| Sebaku Ltd | Transport & logistics | 2019 |
| Secanio Ltd | Professional & scientific | 2021 |
| Secker Capital Ltd | Financial services | 2018 |
| Secoil Limited | Professional & scientific | 2010 |
| Secure Systems (UK) Limited | Construction | 1993 |
| Security Intelligence Global Ltd | Information & communication | 2022 |
| SEE BEE Double YOU Limited | Administrative & support | 2012 |
| SEE Brilliance Holdings Limited | Administrative & support | 2019 |
| SEE Brilliance Limited | Other services | 2006 |
| Seed Technical Ltd | Professional & scientific | 2011 |
| Seine Brooks Ltd | Other services | 2023 |
| Seisrock Geoscience Solution Limited | Professional & scientific | 2016 |
| Select Driving Tours Limited | Professional & scientific | 2023 |
| Select Motorsport Ltd | Wholesale & retail | 2021 |
| Sellers' Representative for Project GEM Limited | Administrative & support | 2013 |
| Sellery Associates Ltd | Professional & scientific | 2010 |
| Sembee Classics Ltd. | Administrative & support | 2015 |
| Sembee Holdings Ltd | Financial services | 2018 |
| Sembee Ltd | Information & communication | 2003 |
| Sembee Property Limited | Real estate | 2016 |
| Sendmin Ltd | Wholesale & retail | 2020 |
| Sentinel Computer Systems Limited | Information & communication | 1997 |
| Septagon Automation Limited | Information & communication | 2007 |
| Septagon Habitation Limited | Financial services | 2024 |
| Septagon Innovation Limited | Information & communication | 2009 |