| Sasw Ltd | Professional & scientific | 2015 |
| Sataman Developments 6 Limited | Construction | 2025 |
| Sataman Developments 7 Limited | Construction | 2025 |
| Satric Developments Limited | Construction | 2021 |
| Satterthwaites Crosby Ltd | Real estate | 1931 |
| Satti Chahal Ltd | Real estate | 2025 |
| Saturn Exhibition & Film Services Limited | Administrative & support | 2003 |
| Savire Limited | Information & communication | 2024 |
| Savvytech Electronics Ltd | Administrative & support | 2017 |
| Saxon Court (Iver) Management Limited | Households | 2008 |
| Saxon Temple Group Limited | Financial services | 2022 |
| SB Business Data Solutions Limited | Wholesale & retail | 2013 |
| SB2 Solutions Ltd | Professional & scientific | 2025 |
| SBH Group Services Ltd | Construction | 2025 |
| SBP Building Services Ltd | Construction | 2013 |
| Scad Software Holdings Limited | Information & communication | 2021 |
| Scad Software Products Limited | Information & communication | 2022 |
| Scad Software UK Limited | Information & communication | 2020 |
| Scarlet Saffron Limited | Wholesale & retail | 2017 |
| Scarsdale Ventures Limited | Professional & scientific | 2008 |
| SCB Serenity and Associates Ltd | Wholesale & retail | 2024 |
| Scgs Consultants Ltd | Information & communication | 2009 |
| Sciving Capital Limited | Professional & scientific | 2024 |
| SCJ Wealth Management Limited | Financial services | 2023 |
| Scope Scaffolding Limited | Construction | 2014 |
| Scopra Ltd | Information & communication | 2025 |
| Scott and Sons Group Ltd | Water & waste | 2019 |
| Scottwood Homes Limited | Construction | 2000 |
| Scrutobyte UK Limited | Information & communication | 2019 |
| SCS Automation UK Limited | Manufacturing | 2014 |
| SCW Stone Solutions Ltd | Professional & scientific | 2025 |
| SD Accountants Limited | Professional & scientific | 2019 |
| SD Global Enterprises Limited | Financial services | 2025 |
| SD Studios - Design & Digital Ltd | Arts & recreation | 2017 |
| Sdet Experts Limited | Information & communication | 2024 |
| SDM Technologies Ltd | Information & communication | 2022 |
| Sdrmc Consultancy Ltd | Manufacturing | 2023 |
| Sdsr Engineering Ltd | Professional & scientific | 2011 |
| SE Digital Ltd | Information & communication | 2024 |
| SE Tattoo Ltd | Other services | 2022 |
| Search Near ME Ltd | Information & communication | 2026 |
| Seaza Limited | Real estate | 2025 |
| Sebastian Roofing & Property Maintenance Ltd | Construction | 2024 |
| Sebson Woods Property Limited | Real estate | 2021 |
| Seburo Ltd | Information & communication | 2017 |
| Sector+ Ltd | Professional & scientific | 2024 |
| Secur-View UK Limited | Information & communication | 2019 |
| Secure Arts Limited | Information & communication | 2003 |
| Secure FD Ltd | Professional & scientific | 2025 |
| Security Control Systems Limited | Administrative & support | 1982 |
| SEE Your Place Ltd | Professional & scientific | 2024 |
| Seebran Consulting Ltd. | Information & communication | 2011 |
| Seedelta Ltd | Professional & scientific | 2025 |
| Seego Properties Limited | Real estate | 2025 |
| Seeme Nutrition Ltd | Health & social care | 2023 |
| Segmetrix Limited | Information & communication | 2023 |
| Sehj Sekhon Limited | Education | 2017 |
| Sekhon Johal & Co Limited | Professional & scientific | 2014 |
| Sekhon Johal Accounting Services Limited | Professional & scientific | 2016 |
| Select Property Leasing Ltd | Real estate | 2022 |
| Sell Fashion Limited | Wholesale & retail | 2023 |
| Seluka Limited | Health & social care | 2022 |
| Semeef Engineering Limited | Administrative & support | 2016 |
| Sememe Consulting Ltd | Professional & scientific | 2026 |
| Semolina Pilchard Ltd | Professional & scientific | 2021 |
| SEN Ichie Limited | Hospitality | 2023 |
| Send ME a Sample Limited | Information & communication | 2018 |
| Sense Intelligence Limited | Education | 2006 |
| Sensorion Limited | Professional & scientific | 2024 |
| Sent Properties Limited | Real estate | 2024 |
| Sentient Secure Ltd | Professional & scientific | 2023 |
| Sentinel Clinical Analytics Ltd | Professional & scientific | 2025 |
| Sentinel System Safety Ltd | Administrative & support | 2008 |
| Sequans Communications Limited | Information & communication | 2005 |
| Sequence Nutrition Limited | Information & communication | 2014 |
| Sequoia Hair Limited | Other services | 2019 |
| Serendipity Day Nursery Limited | Education | 2003 |
| Serenity Systems Limited | Information & communication | 2005 |
| Sergene Biosciences Ltd | Professional & scientific | 2024 |
| SET Equip Limited | Manufacturing | 2011 |
| SEW NOT Limited | Wholesale & retail | 2009 |
| Sewisfaction Ltd | Wholesale & retail | 2017 |
| SFI Advisory Ltd | Administrative & support | 2024 |
| Sfp&D Ltd | Construction | 2019 |
| SG HR Solutions Ltd | Administrative & support | 2017 |
| SG Tax Limited | Professional & scientific | 2024 |
| SGC Plumbing and Heating Ltd | Construction | 2020 |
| SH Truck Hire Ltd | Administrative & support | 2017 |
| Shade Custom Ltd | Wholesale & retail | 2022 |
| Shaedon Consulting Limited | Information & communication | 2018 |
| Shan School Transport Limited | Transport & logistics | 2024 |
| Shanaaya Ltd | Real estate | 2017 |
| Shanaya Solutions Ltd | Professional & scientific | 2020 |
| Shanice Medical Care Ltd | Health & social care | 2019 |
| Shankstaa Limited | Wholesale & retail | 2025 |
| Shanti and Atul Properties Limited | Real estate | 2020 |
| Shanti Medical Ltd | Health & social care | 2021 |
| Sharonelle Court (Wokingham) Management Limited | Households | 1978 |
| Sharp Property Limited | Financial services | 2016 |
| Sharva Enterprises Ltd | Information & communication | 2019 |