| Scratch PAD Ltd | Other services | 2006 |
| Scre Services Limited | Real estate | 2021 |
| Screemaction Limited | Administrative & support | 2018 |
| Screen Repair Services Limited | Manufacturing | 2003 |
| Scribes Analysis Limited | Information & communication | 2011 |
| Scruffy Duck Solutions Ltd | Professional & scientific | 2017 |
| SCS Waste Limited | Administrative & support | 2023 |
| Scsl SG Holdings Limited | Financial services | 2024 |
| Scunthorpe Specsavers Hearcare Limited | Wholesale & retail | 2006 |
| SD Bioinformatics Limited | Professional & scientific | 2021 |
| SD Card Express Ltd | Wholesale & retail | 2019 |
| SDB Retail Limited | Wholesale & retail | 2020 |
| Sdcl Ltd | Construction | 2025 |
| SDM Group Ltd | Health & social care | 2024 |
| Sea Breeze Fishing Ltd | Agriculture & fishing | 2019 |
| Sea Sage Consulting Ltd | Professional & scientific | 2023 |
| Sea Salt Build Limited | Construction | 2017 |
| SEA7S.UK Ltd | Professional & scientific | 2024 |
| Seachange Marine Ltd | Professional & scientific | 2024 |
| Seaeye Limited | Extraterritorial | 1999 |
| Seafarer Social Consultants Ltd | Real estate | 2023 |
| Seaford Specsavers Hearcare Limited | Wholesale & retail | 2024 |
| Seaford Specsavers Limited | Wholesale & retail | 2004 |
| Seaford Visionplus Limited | Wholesale & retail | 2004 |
| Seagrouth Ltd | Health & social care | 2021 |
| Seaham Specsavers Limited | Wholesale & retail | 2007 |
| Seaham Visionplus Limited | Wholesale & retail | 2007 |
| Seahawk Consultancy Limited | Other services | 2016 |
| Sean Barrett Rentals Ltd | Real estate | 2026 |
| Sean MC Tiernan Locum Ltd | Professional & scientific | 2019 |
| Sean Whelan Limited | Administrative & support | 2025 |
| Searle Refrigeration Products Ltd | Professional & scientific | 2013 |
| Seastar Survey Limited | Administrative & support | 2007 |
| Seatraul Limited | Financial services | 2023 |
| Seaview Residential Home Limited | Health & social care | 2003 |
| Seaway Developments Ltd | Construction | 2025 |
| Seawork Limited | Manufacturing | 1986 |
| Sebbea Ltd | Real estate | 2023 |
| Second to None Hair Studio Limited | Other services | 2003 |
| Secondwave Voyage CIC | Professional & scientific | 2026 |
| Secura Holdings Limited | Manufacturing | 2019 |
| Secure Funeral Solutions Ltd | Financial services | 2015 |
| Secure Vision Technologies Ltd | Administrative & support | 2020 |
| Secured Spaces Ltd | Transport & logistics | 2023 |
| Security AS a Service Ltd | Information & communication | 2022 |
| SED Financial Limited | Financial services | 2015 |
| Seddon Property Solutions Ltd | Real estate | 2023 |
| Seek Management Limited | Administrative & support | 2022 |
| Segensworth Automobiles Limited | Wholesale & retail | 1990 |
| Segensworth Roofing & Maintenance Ltd | Construction | 2025 |
| Seguimos Advisory Limited | Professional & scientific | 2025 |
| SEH Clinical Research Ltd | Professional & scientific | 2017 |
| Seino Consultancy Ltd | Professional & scientific | 2025 |
| Sejemba & Omakobia Properties Ltd | Real estate | 2023 |
| Sekoula Freight Ltd | Transport & logistics | 2023 |
| Selby Specsavers Limited | Wholesale & retail | 2002 |
| Select Generation Ltd | Arts & recreation | 2025 |
| Select GMS Limited | Administrative & support | 2016 |
| Sellaphone Limited | Extraterritorial | 2017 |
| Selly Oak Specsavers Limited | Wholesale & retail | 2018 |
| Seneca Detailing Limited | Wholesale & retail | 2025 |
| Seniorcare UK Propco Holdco Limited | Financial services | 2021 |
| Seniorcare UK Propco Limited | Financial services | 2021 |
| Seniorcare UK Propco SUB Limited | Real estate | 2021 |
| Senro Limited | Wholesale & retail | 2008 |
| Sensational Cakes and Desserts Ltd | Manufacturing | 2023 |
| Sensecere CIC | Health & social care | 2019 |
| Sensible Gifts Ltd | Wholesale & retail | 2000 |
| Sentutordirect Ltd | Education | 2023 |
| Serendip Home Care Limited | Health & social care | 2017 |
| Serenity Holidays Ltd. | Administrative & support | 1983 |
| Sergya Ltd | Wholesale & retail | 2025 |
| Series a Roofing Ltd | Construction | 2011 |
| Series of Dreams Limited | Professional & scientific | 2016 |
| Serious Feather Ltd | Information & communication | 2026 |
| Serpentine Green Specsavers Limited | Wholesale & retail | 2013 |
| Sert Workforce Solutions Limited | Administrative & support | 2011 |
| Seruse Food & Digital Service Ltd | Hospitality | 2022 |
| Serverhouse Limited | Administrative & support | 1997 |
| Service Dogs UK | Health & social care | 2015 |
| Service My GAS Boiler Ltd | Other services | 2015 |
| SES Document Control Ltd | Administrative & support | 2026 |
| SET Builds Southern Ltd | Construction | 2023 |
| Seven Internet Limited | Information & communication | 2005 |
| Seven Ventures Group Ltd | Real estate | 2024 |
| Sevenoaks Specsavers Hearcare Limited | Wholesale & retail | 2022 |
| Sevenoaks Specsavers Limited | Wholesale & retail | 2007 |
| Sevenoaks Visionplus Limited | Wholesale & retail | 2007 |
| Sever & SON Consultancy Limited | Professional & scientific | 2014 |
| SEW Fabulous Fabrics Ltd | Wholesale & retail | 2019 |
| Sexton Roofing Limited | Construction | 2018 |
| SF Garden Services & Grounds Maintenance Ltd | Administrative & support | 2024 |
| SF Property Estates Ltd | Other services | 2025 |
| SFC Employee (Holdings) Limited | Financial services | 2019 |
| SFX Collectible Ltd | Manufacturing | 2025 |
| SG Filkins Holdings Ltd | Financial services | 2023 |
| SG Sports Turf Ltd | Wholesale & retail | 2025 |
| Sgdn Limited | Real estate | 2002 |
| Sgritheall Ltd | Information & communication | 2014 |
| SGS Equipment Ltd | Administrative & support | 2017 |