| SMG Design (UK) Ltd | Administrative & support | 2014 |
| Smigt&R Ltd | Wholesale & retail | 2025 |
| SMK Stores Ltd | Wholesale & retail | 2019 |
| SML Sourcing & Marketing Link Ltd | Wholesale & retail | 2014 |
| SMO UK Limited | Other services | 2008 |
| Smooth Driving Ltd | Transport & logistics | 2019 |
| SMP Training & Recruitment Limited | Information & communication | 2019 |
| SMR Garage Services Ltd | Wholesale & retail | 2025 |
| Smrhs Limited | Construction | 2009 |
| Snapoff Print Services Limited | Wholesale & retail | 2013 |
| Sniffer Media Limited | Information & communication | 2014 |
| Snowdrop Investments Ltd | Real estate | 2025 |
| SO Cold Refrigeration Ltd | Professional & scientific | 2026 |
| SOB SAM Limited | Wholesale & retail | 2024 |
| Social Contract C.I.C. | Administrative & support | 2024 |
| Social Entrepreneur Place Ltd | Information & communication | 2003 |
| Social Media WOW Ltd | Professional & scientific | 2022 |
| Social Players Ltd | Information & communication | 2026 |
| Soden (Oundle RD) Ltd | Real estate | 2021 |
| Soden (the Martins) Ltd | Real estate | 2021 |
| Softscape Gardens Ltd | Other services | 2021 |
| Software Aspects Limited | Information & communication | 2014 |
| Solenoid Software Solutions Ltd | Information & communication | 2025 |
| Sologica Limited | Extraterritorial | 2008 |
| Solrayze Ltd | Other services | 2025 |
| Solve Engineering Design Limited | Other services | 2006 |
| Someone Else's Country Ltd | Administrative & support | 2026 |
| Somersham Community Library (Fosl) | Arts & recreation | 2012 |
| Somersham Grange Limited | Hospitality | 1990 |
| Somersham Local Store Ltd | Wholesale & retail | 2017 |
| Sonder Tapes Ltd | Wholesale & retail | 2024 |
| Sonetic International Consultancy Limited | Professional & scientific | 2023 |
| Song & Family Ltd | Wholesale & retail | 2019 |
| Soparco UK Limited | Wholesale & retail | 2008 |
| Sorexing Ltd | Professional & scientific | 2026 |
| SOS Automotive Ltd | Wholesale & retail | 2020 |
| SOS Property Management 2 Limited | Financial services | 2022 |
| SOS Property Management HMO Limited | Real estate | 2022 |
| SOS Property Management Limited | Financial services | 2014 |
| SOS+ Limited | Professional & scientific | 1959 |
| Sotnyk Prime Ltd | Transport & logistics | 2025 |
| Soulfish Limited | Information & communication | 2006 |
| Sounds Together Limited | Information & communication | 2011 |
| Sovereign Court Management Co. Ltd. | Real estate | 1990 |
| Sowinskidriver 01 Limited | Transport & logistics | 2015 |
| SP Bookkeeping & Accounts Ltd | Professional & scientific | 2025 |
| Sp-Logistics Holdings Ltd | Financial services | 2017 |
| Sparcle Clean Team Limited | Administrative & support | 2022 |
| Sparx Cars Limited | Transport & logistics | 2018 |
| SPC Verlag Limited | Manufacturing | 2004 |
| Special Choices Limited | Education | 2010 |
| Special Days Designs Limited | Wholesale & retail | 2015 |
| Specialist Fire & Security Ltd | Administrative & support | 2013 |
| Specnow Ltd | Manufacturing | 2004 |
| Spectre Digital Ltd | Information & communication | 2017 |
| SPEEDDRIVE4U Ltd | Transport & logistics | 2020 |
| Spencer Court Limited | Real estate | 2004 |
| Speranza Bozena Ltd | Public administration | 2025 |
| Sperling Estate Limited | Extraterritorial | 1997 |
| Spex UK Limited | Wholesale & retail | 2022 |
| Spice Mafia UK Ltd | Manufacturing | 2025 |
| Spinney Lane Residents Association Limited | Real estate | 1994 |
| Spirotech Group Ltd | Manufacturing | 2019 |
| Spirotech York Limited | Manufacturing | 2015 |
| Spitfire Avian Pest Control Ltd | Agriculture & fishing | 2018 |
| Spjr Consulting Limited | Administrative & support | 2016 |
| Splash Patrol Ltd | Education | 2024 |
| Sports Connections Foundation | Education | 2009 |
| Spotty Octopus Limited | Information & communication | 2018 |
| Springfield Place (Newbury Park) Management Company Limited | Households | 1992 |
| Springfresh Carpet & Upholstery Cleaning Limited | Administrative & support | 2019 |
| Springrock Limited | Administrative & support | 1995 |
| SPS Robert Labanowski Ltd | Wholesale & retail | 2025 |
| Spuds & Dough Ltd | Hospitality | 2024 |
| Spyro Consulting Ltd | Professional & scientific | 2021 |
| SR Amedeo Ltd | Health & social care | 2020 |
| SR Howell & Co (Ramsey) Limited | Professional & scientific | 2002 |
| SR Wind Limited | Construction | 2012 |
| SR56 Limited | Real estate | 2021 |
| SRJ Software Solutions Ltd | Information & communication | 2020 |
| Srrbn Ltd | Health & social care | 2020 |
| SRS Security Limited | Administrative & support | 2025 |
| SRT Developments (Cambs) Ltd | Construction | 2018 |
| SS Consulting Services PVT Limited | Professional & scientific | 2022 |
| Ssmb Group Limited | Construction | 2021 |
| ST Dominic's Residential Ltd | Construction | 2026 |
| ST Drivers Ltd | Transport & logistics | 2021 |
| ST Ives Bouncy Castle Hire Ltd | Administrative & support | 2016 |
| ST Ives Tile & Stone Ltd | Wholesale & retail | 2007 |
| ST John's Property Investments Limited | Financial services | 2025 |
| ST Margaret's Residential Ltd | Construction | 2026 |
| ST Mary's Care Home (Stone) Limited | Health & social care | 2025 |
| ST Neots Exhibitions Ltd | Other services | 2011 |
| ST Neots Learning and Sport Academy Ltd | Education | 2015 |
| ST Opis Ltd | Wholesale & retail | 2025 |
| ST. Ann's Court (Godmanchester) Management Company Limited | Households | 1986 |
| ST. Legers Mews Management Company Limited | Households | 2012 |
| ST. Neots Motorcycle Co Limited | Wholesale & retail | 1976 |
| Stair Formwork Limited | Manufacturing | 2020 |
| Stamford Aesthetics Ltd. | Education | 2013 |