| Spoon Solutions Ltd | Construction | 2026 |
| Sports & Prestige Marlow Ltd | Wholesale & retail | 2023 |
| Sportsamp.Ai Ltd | Information & communication | 2025 |
| Sportworx UK Limited | Wholesale & retail | 2018 |
| Spotlight Insight Limited | Professional & scientific | 2018 |
| Spray Finishes Limited | Construction | 2016 |
| Springclose Property Co. Limited | Administrative & support | 2003 |
| Springfield Global UK Limited | Wholesale & retail | 2018 |
| Springfields (Residents) Limited | Households | 1988 |
| Springwell Clinic Holdings Ltd | Financial services | 2023 |
| Springwell Clinic Ltd | Health & social care | 2014 |
| Springwell Clinic Marlow Ltd | Health & social care | 2022 |
| Squirrel IT Ltd | Information & communication | 2015 |
| SR Hospitality Management Limited | Hospitality | 2026 |
| Srbc Holdings Ltd | Real estate | 2022 |
| SRI SAI Balaji Properties Limited | Real estate | 2026 |
| Srisankar Limited | Wholesale & retail | 2013 |
| SRM Business Consulting Ltd | Professional & scientific | 2016 |
| ST David's Nursing Home and ST Christopher's Care Home Ltd | Real estate | 2018 |
| ST Francis Close Tring (Management) Limited | Households | 2019 |
| ST John Mews Residents Management Company Limited | Households | 2019 |
| ST. Catherine's House (Wethered Park) Limited | Real estate | 1998 |
| ST. James Courtyard (Marlow) Residents Association Ltd | Households | 1988 |
| ST. Johns House (Wethered Park) Limited | Real estate | 1998 |
| St.Mary's Mead (Maidenhead) Management Limited | Households | 1989 |
| Staines Town Football Club Limited | Arts & recreation | 2025 |
| Stairway Consultancy Limited | Professional & scientific | 1989 |
| Stampin' UP! UK Limited | Wholesale & retail | 2007 |
| Stardust Agency Limited | Professional & scientific | 2025 |
| Starling MAY Ltd | Professional & scientific | 2017 |
| Stars Investments Ltd | Real estate | 2012 |
| Startly Ltd | Administrative & support | 2024 |
| Statham Consulting Ltd | Professional & scientific | 2023 |
| Statusbrew Ltd | Information & communication | 2025 |
| Stefan's Butchers Limited | Wholesale & retail | 2014 |
| Stekko Company Limited | Manufacturing | 1990 |
| Stephanie Howard Consulting Ltd | Other services | 2025 |
| Stephen Patrick Ltd | Administrative & support | 2011 |
| Steps Design Ltd | Construction | 2023 |
| Sterling & Associates Limited | Professional & scientific | 1987 |
| Sterling Associates Limited | Professional & scientific | 1989 |
| Sters Cleaning Service Ltd | Administrative & support | 2022 |
| Stevend Engineering Limited | Manufacturing | 2003 |
| Stevend Limited | Manufacturing | 1973 |
| Stilo Group Services Ltd | Information & communication | 2026 |
| Stilo Professional Services Ltd | Information & communication | 2024 |
| Stimson Consulting Limited | Professional & scientific | 2010 |
| Stmicroelectronics (Bristol) Pension Trust Ltd | Professional & scientific | 1980 |
| Stmicroelectronics (Research & Development) Limited | Professional & scientific | 1962 |
| Stmicroelectronics Limited | Manufacturing | 1962 |
| Stoke Road Developments Limited | Construction | 2018 |
| Stokewood Development Ltd | Professional & scientific | 2003 |
| Stoney Ware Estate Limited | Agriculture & fishing | 1999 |
| Stoney Ware Residents Association Company Limited(The) | Households | 1966 |
| Store Relevance Ltd | Information & communication | 2020 |
| STR8 Paint Ltd | Wholesale & retail | 2023 |
| STR8 Vehicle Storage Ltd | Transport & logistics | 2024 |
| Strangemap Limited | Information & communication | 2013 |
| Strawberry Grove Marlow Limited | Hospitality | 2019 |
| Straylight Agency Limited | Professional & scientific | 2021 |
| Stream Limited | Professional & scientific | 1998 |
| Struan ES Services Ltd | Construction | 2016 |
| Studio AD Limited | Other services | 2019 |
| Studio BIA Ltd | Wholesale & retail | 2025 |
| Studio Cbel Ltd | Professional & scientific | 2022 |
| Studio Crispin Limited | Arts & recreation | 2021 |
| Studio Denne Ltd | Construction | 2025 |
| Studio HAM Limited | Professional & scientific | 2017 |
| Studio Sagar Limited | Professional & scientific | 2025 |
| Styal Construction Services Limited | Real estate | 1988 |
| Styled Furniture Packs LLP | | 2018 |
| Subby-Jobs Ltd | Information & communication | 2017 |
| Sugoi Hospitality Ltd | Professional & scientific | 2023 |
| Summit 3 Leisure Clubs Ltd | Arts & recreation | 2017 |
| Summit Leisure Clubs Ltd | Arts & recreation | 2011 |
| Sunday Season Ltd | Wholesale & retail | 2026 |
| Sunstone-Group Limited | Professional & scientific | 2025 |
| Superfy Ltd | Professional & scientific | 2020 |
| Superline Limited | Manufacturing | 2002 |
| Supplied Solutions Ltd | Professional & scientific | 2009 |
| Supplyfi UK Ltd | Information & communication | 2025 |
| Surescan Corporation UK Ltd | Manufacturing | 2024 |
| Susan Hughes Publishing Limited | Professional & scientific | 2015 |
| Sustainable Growth Business Services Limited | Administrative & support | 2023 |
| Sustainabuild Ltd | Construction | 2025 |
| Suum Vietnamese Kitchen Ltd | Hospitality | 2017 |
| Suzanna Lawrence Associates Ltd | Professional & scientific | 2024 |
| Svire Ltd | Wholesale & retail | 2023 |
| Swadling Building Contractors Ltd | Construction | 2021 |
| Swan House Estates Limited | Households | 1987 |
| Swayu Limited | Wholesale & retail | 2026 |
| Sydney Aesthetics Limited | Wholesale & retail | 2016 |
| Symbia Ltd | Professional & scientific | 2013 |
| Symeon Place Residents Management Company Two Limited | Households | 2007 |
| Symogen Ltd | Health & social care | 2004 |
| Syna Ltd | Extraterritorial | 2020 |
| Synergy Computer Services Limited | Construction | 1999 |
| Synergy Technical Solutions Ltd | Construction | 2018 |
| Sytemaker.Com Ltd | Information & communication | 2002 |
| T & K News Limited | Wholesale & retail | 2016 |