| Sougou Limited | Health & social care | 2018 |
| Southern Regalia Limited | Wholesale & retail | 2011 |
| Southpac Limited | Wholesale & retail | 1999 |
| Spark Hospitality Ltd | Education | 2015 |
| Sparrow Ventures Limited | Construction | 2025 |
| Spatial Ecology | Professional & scientific | 2015 |
| Speakeasy Booth Co Ltd | Manufacturing | 2026 |
| Spectra Science Limited | Professional & scientific | 2008 |
| Spectrakey Ltd | Manufacturing | 2010 |
| Speedeck Construction Limited | Construction | 2017 |
| Speedeck Foundations Limited | Construction | 2014 |
| Speedeck Property Ltd | Real estate | 2021 |
| Spence Homes Limited | Real estate | 2025 |
| Spencer Bull Recruitment Limited | Professional & scientific | 2001 |
| SPG Consulting Engineers Limited | Professional & scientific | 2015 |
| Spice Commercial Legal Services Limited | Professional & scientific | 2015 |
| Spice of Chesham Ltd | Hospitality | 2019 |
| Spice Safari Tours Ltd | Administrative & support | 2024 |
| SPY Studio Ltd | Professional & scientific | 2003 |
| SRL Accounting & Advisory Ltd | Professional & scientific | 2026 |
| SRL Accounting Group Ltd | Professional & scientific | 2016 |
| SRL Accounting Limited | Professional & scientific | 2003 |
| Srpi Consumer Services Ltd | Information & communication | 2010 |
| Ssvb Properties Limited | Real estate | 2022 |
| Stadium Finance Limited | Other services | 1955 |
| Stampnotes Limited | Information & communication | 1988 |
| Stand UP and Deliver London Limited | Administrative & support | 2005 |
| Stansburys Developments Ltd | Real estate | 2022 |
| Stansburys Limited | Professional & scientific | 2004 |
| Stanwix Limited | Construction | 2016 |
| Star JAM Ltd | Wholesale & retail | 2023 |
| Starke Consultancy Ltd | Health & social care | 2018 |
| Startled Bunny Productions Limited | Professional & scientific | 1999 |
| Station Garage Chesham Ltd | Wholesale & retail | 2020 |
| Station Garage GM Limited | Real estate | 2014 |
| Station Yard (Wendover) Limited | Administrative & support | 1997 |
| Step Forward Insights Ltd | Information & communication | 2025 |
| Stephen Yerby Limited | Construction | 2017 |
| Sterling Real Estate Ltd | Real estate | 2020 |
| Sterling Softeners Limited | Wholesale & retail | 2007 |
| Sterling Windscreens Limited | Administrative & support | 2004 |
| Steve Barnett Plumbing & Bathrooms Limited | Construction | 2004 |
| Steve Barnett Plumbing & Heating Ltd | Extraterritorial | 2018 |
| Storage Online Limited | Administrative & support | 2006 |
| Storms Fencing Ltd | Administrative & support | 2011 |
| Stott Medical Ltd | Health & social care | 2023 |
| Stotter Ltd | Wholesale & retail | 2020 |
| Strange Force Records Ltd | Arts & recreation | 2017 |
| Strategem Land Ltd | Real estate | 2026 |
| Stratospheric Airship Technologies (SAT) Limited | Professional & scientific | 2012 |
| Stratospheric Airship Technologies UK Limited | Professional & scientific | 2004 |
| Streatham Trading Ltd | Wholesale & retail | 2025 |
| Streetwxrks Ltd | Wholesale & retail | 2021 |
| Stretton Partners Ltd | Construction | 1998 |
| Strike One Consultancy Limited | Education | 2015 |
| Stuart Hall Golf Limited | Arts & recreation | 2022 |
| Stuart Mccurry & Partners Limited | Administrative & support | 2001 |
| Student Buddy Ltd | Information & communication | 2010 |
| Studio 109 Limited | Construction | 2016 |
| Studio Beam Ltd | Information & communication | 2012 |
| Studio DLM Ltd | Professional & scientific | 2021 |
| Studio Logistics Ltd | Transport & logistics | 2019 |
| Studio MU Ltd | Professional & scientific | 2025 |
| Studio Neve Ltd | Professional & scientific | 2023 |
| STUDIO2359 Ltd | Information & communication | 2023 |
| SU Chases Interiors Ltd | Wholesale & retail | 2003 |
| Subtilitas Investments Ltd | Real estate | 2023 |
| Success Redefined Limited | Administrative & support | 2017 |
| Sufficient Storage Limited | Transport & logistics | 2022 |
| Sukros Ltd | Information & communication | 2019 |
| Summerlin Builders Ltd | Construction | 2024 |
| Summit Roofing Ltd | Construction | 2016 |
| Sundance Multiprocessor Technology Limited | Manufacturing | 1989 |
| Sunnymede Avenue Residents Association Ltd. | Hospitality | 2002 |
| Super Heavy Ltd | Professional & scientific | 2024 |
| Super Lucky Family Limited | Wholesale & retail | 2019 |
| Supreme Oral Care Limited | Health & social care | 2022 |
| Surely Knott Limited | Information & communication | 2023 |
| Surrey Landscapers Ltd | Administrative & support | 2022 |
| Susanna Blinds and Curtains Ltd | Manufacturing | 2024 |
| Sussex Realty Ltd | Real estate | 2015 |
| Sussex Realty Management Ltd | Real estate | 2016 |
| Sussum Consulting Ltd | Administrative & support | 2019 |
| Sustainable Innovations Ltd | Wholesale & retail | 2022 |
| Sutton Heights Limited | Financial services | 1997 |
| Sutton Heights Management Services Limited | Real estate | 2005 |
| SVP Property Services Ltd | Real estate | 2026 |
| Swa'Delicious Ltd. | Wholesale & retail | 2018 |
| Swami Krupa Chiltern Ltd | Wholesale & retail | 2025 |
| Swimming and Leisure Management Ltd | Arts & recreation | 2021 |
| Swiss Group Team Limited | Wholesale & retail | 2022 |
| Switchwise Limited | Information & communication | 2002 |
| Synergy Offshoring Ltd | Professional & scientific | 2023 |
| Synergy Strategic Partners Limited | Professional & scientific | 2023 |
| Systemik Ltd | Arts & recreation | 2025 |
| T & SON Investments Ltd | Real estate | 2026 |
| T Ward Developments Ltd | Real estate | 2023 |
| T.L. Contracting Limited | Construction | 1999 |
| T21 Hair Ltd | Other services | 2022 |
| Tabletop Upgrades Ltd | Manufacturing | 2020 |