| Sequoia Strategic Consulting Ltd | Professional & scientific | 2022 |
| Serandib Consultancy Limited | Professional & scientific | 2014 |
| Seranora Care Ltd | Health & social care | 2026 |
| Serenitea Ltd | Manufacturing | 2026 |
| Serenity Base Limited | Hospitality | 2025 |
| Serious Point Games Ltd | Information & communication | 2024 |
| Servernet Internet Limited | Information & communication | 2019 |
| Service Management Consultancy Limited | Information & communication | 1991 |
| Sessile Construction Limited | Construction | 2017 |
| SET Piece Events Limited | Arts & recreation | 2011 |
| SET Ready Greens Limited | Administrative & support | 2017 |
| Setify Ltd | Professional & scientific | 2024 |
| Setpoint Properties Limited | Construction | 1997 |
| Seven Seas General Trading Ltd | Wholesale & retail | 2022 |
| SEVENTY5 Ltd | Information & communication | 2003 |
| SF UK Consultant Ltd | Professional & scientific | 2023 |
| SFA Berkshire Ltd | Real estate | 2026 |
| Sfia 2020 Limited | Financial services | 2019 |
| Sfia Wealth Management Limited | Financial services | 2014 |
| SG Collaborative Ltd | Professional & scientific | 2022 |
| SG IT Solutions Ltd | Information & communication | 2025 |
| SGR Consultancy Services Ltd | Professional & scientific | 2017 |
| SGT Select Limited | Wholesale & retail | 2012 |
| SGW Services Limited | Construction | 2015 |
| Shaba's Landscaping Services Ltd | Administrative & support | 2024 |
| Shadeal Limited | Wholesale & retail | 2021 |
| Shadow Carriage Ltd. | Transport & logistics | 2004 |
| Shadowgrid Solutions Limited | Wholesale & retail | 2025 |
| Shadows Fall Media Limited | Arts & recreation | 2013 |
| Shahba Rose Food Ltd | Hospitality | 2024 |
| Shahbaz and Sons Ltd | Real estate | 2021 |
| Shahzadi Afshan Ltd | Wholesale & retail | 2022 |
| Shaikit Limited | Information & communication | 2011 |
| Shangri-La International PTE Limited | Hospitality | 1983 |
| Shani Events Limited | Professional & scientific | 2011 |
| Shape Workspace Limited | Other services | 2010 |
| Shapedirect Limited | Financial services | 1997 |
| Share Jesus | Extraterritorial | 2001 |
| Sharp Insights INT Ltd | Professional & scientific | 2012 |
| Sharp Rail Engineering Services Ltd | Construction | 2014 |
| Shaun Goddard Limited | Information & communication | 2003 |
| Shaw + Scott Ltd. | Other services | 2016 |
| Shaycmak Ltd | Real estate | 2022 |
| Shazohpar Tea Co UK Limited | Wholesale & retail | 2020 |
| Sheaf Ltd | Information & communication | 2026 |
| Shearn Holdings Ltd | Financial services | 2025 |
| Shearn Property Limited | Real estate | 2023 |
| Shearn Property NO 1 Limited | Construction | 2025 |
| Shearwater Group Holdings Ltd | Financial services | 2021 |
| Sheephouse Country Cottages Limited | Hospitality | 1999 |
| Shellscape Pyrotechnics Limited | Manufacturing | 1998 |
| Shena Jina Ltd | Health & social care | 2019 |
| Sher Build Ltd | Construction | 2024 |
| Sher Fight Club Ltd | Wholesale & retail | 2024 |
| Sheridan Court Management (Maidenhead) Limited | Households | 1973 |
| Shiell Designs Ltd | Wholesale & retail | 2018 |
| Shift Analytics Ltd | Transport & logistics | 2026 |
| Shiksak Learning Solutions Ltd | Information & communication | 2015 |
| Shilajit Life Ltd | Wholesale & retail | 2022 |
| Shilland Farm LLP | | 2022 |
| Shilpam Limited | Information & communication | 2005 |
| Shinez Windows Cleaning Services Limited | Administrative & support | 2025 |
| Shiny Linings Limited | Professional & scientific | 2020 |
| Shiv AUM Properties Limited | Real estate | 2019 |
| Shoeprint Ltd | Wholesale & retail | 2024 |
| Shoiminatrix Ltd | Health & social care | 2007 |
| SHONAN20 Limited | Administrative & support | 2024 |
| Shop Daily Ltd | Wholesale & retail | 2018 |
| Shop ROW Ltd | Real estate | 2024 |
| Shopiley Limited | Wholesale & retail | 2023 |
| Shopok Ltd | Wholesale & retail | 2021 |
| Shotsy & Co Ltd | Professional & scientific | 2024 |
| Shoukat & Sons Limited | Wholesale & retail | 2015 |
| Shra Ltd | Wholesale & retail | 2023 |
| Shri Limited | Construction | 2005 |
| Shri Shyam Transport and Packaging Ltd | Transport & logistics | 2025 |
| Shropshire Waste Management Limited | Water & waste | 1991 |
| Shudex Limited | Transport & logistics | 2014 |
| Shukco 2020 Ltd | Extraterritorial | 2020 |
| Shukco 303 Limited | Professional & scientific | 1989 |
| Shukco 323 Ltd | Extraterritorial | 1994 |
| Shukco 327 Ltd | Financial services | 1996 |
| Shukco 340 Ltd | Financial services | 1997 |
| Shukco 341 Ltd | Extraterritorial | 1994 |
| Shukco 342 Ltd | Financial services | 1994 |
| Shukco 345 Ltd | Financial services | 1984 |
| Shukco 350 Ltd | Professional & scientific | 1981 |
| Shukco Ltd | Financial services | 1984 |
| Shute END Holdings Limited | Real estate | 2002 |
| Shutters & Blinds Berkshire Ltd | Other services | 2024 |
| SIA Technology Limited | Information & communication | 2016 |
| Sian Fever Limited | Information & communication | 2012 |
| Sibis Limited | Information & communication | 2017 |
| Sidebro Ltd | Professional & scientific | 2026 |
| Siega Ltd | Information & communication | 2023 |
| SIERRALIMA6 Ltd | Information & communication | 2018 |
| Sign Guru Limited | Manufacturing | 2012 |
| Signpoint Limited | Manufacturing | 2013 |
| Signs Direct (UK) Ltd | Wholesale & retail | 1996 |
| Sigtech Clinical Limited | Information & communication | 2014 |