| Rowan Carter Limited | Construction | 2020 |
| RS Sheet Metal Ltd. | Manufacturing | 1999 |
| Rspb Sales Limited | Agriculture & fishing | 1992 |
| Ruby Film and Television (Dote) Limited | Administrative & support | 2011 |
| Ruby Film and Television Limited | Administrative & support | 2010 |
| Ruby Films (Jane Eyre) Ltd | Administrative & support | 2009 |
| Ruby Films (Tamara Drewe) Limited | Administrative & support | 2009 |
| Ruby Films (Toast) Limited | Administrative & support | 2010 |
| Ruby Films Limited | Information & communication | 1998 |
| Russell Hunter Contracting Limited | Transport & logistics | 2014 |
| S L Gurry and SON Ltd. | Agriculture & fishing | 2024 |
| S P and Sons Holding Ltd | Real estate | 2021 |
| S R Darlow Building Ltd | Construction | 2014 |
| S&B Murphy Limited | Construction | 2015 |
| S.P. Equine Limited | Wholesale & retail | 1994 |
| S.T.U. Solutions Limited | Information & communication | 2025 |
| Safe Used Autos Limited | Wholesale & retail | 2020 |
| Safecell Ltd | Professional & scientific | 2019 |
| Safwaan Ltd | Information & communication | 2024 |
| Salt Beef and Chips Limited | Extraterritorial | 2018 |
| Sandford Accounting Ltd | Professional & scientific | 2017 |
| Sandy Airfield Limited | Arts & recreation | 2014 |
| Sandy Chef Ltd | Hospitality | 2023 |
| Sandy Fryer Ltd | Hospitality | 2025 |
| Sandy Grab Services Limited | Water & waste | 2021 |
| Sandy Grill Ltd | Hospitality | 2025 |
| Sandy Helping Hands Counselling & Guidance Centre Ltd | Other services | 2010 |
| Sandy Indian Limited | Hospitality | 2018 |
| Sandy Mill Residents Association Limited | Professional & scientific | 1984 |
| Sandy Music Festival CIC | Health & social care | 2024 |
| Sandyvale Vets Ltd | Professional & scientific | 2025 |
| Sandywood Homes Limited | Construction | 2017 |
| Sanwalton Limited | Professional & scientific | 1999 |
| Sarracino Wine Bar Limited | Hospitality | 2025 |
| Satsuma Electronics Ltd | Manufacturing | 2018 |
| Saturn Consultancy Services Limited | Information & communication | 2015 |
| Saveo Ltd | Professional & scientific | 2024 |
| Savin Wholesalers Limited | Wholesale & retail | 2016 |
| SCB Holdings (Sandy) Limited | Professional & scientific | 2000 |
| SCB Residential Limited | Real estate | 1980 |
| Science Swift Limited | Other services | 2021 |
| Scott Ritchie Productions Ltd | Arts & recreation | 2016 |
| Scott Roofing Ltd | Construction | 2010 |
| Scout & Stan Ltd | Information & communication | 2022 |
| Scruff & Pooch Ltd | Wholesale & retail | 2022 |
| SDC Business Solutions Limited | Professional & scientific | 2009 |
| SDC Cool Solutions Limited | Extraterritorial | 2011 |
| SDW Trading Limited | Professional & scientific | 2011 |
| Seaair Ltd | Wholesale & retail | 2022 |
| Seako Construction Group Ltd | Construction | 2020 |
| Seako Holdings Ltd | Construction | 2023 |
| Seako Homes Sawtry Ltd | Construction | 2023 |
| Secret Global Limited | Wholesale & retail | 2020 |
| Securecps Limited | Information & communication | 2025 |
| Sedelton Ltd | Wholesale & retail | 2026 |
| Self-Lay Limited | Water & waste | 2020 |
| Selfish Giant Film Ltd | Administrative & support | 2012 |
| Sensible PC Support Limited | Information & communication | 2020 |
| Serenity Scaffolding Limited | Construction | 2019 |
| Settled Immigration Limited | Professional & scientific | 2024 |
| Seven Owls Limited | Information & communication | 2012 |
| Shevlane Associates Ltd | Construction | 2017 |
| Shingleback Limited | Administrative & support | 2014 |
| Showcase Trailers Ltd | Manufacturing | 2026 |
| Shuttle Transport Limited | Transport & logistics | 2006 |
| Siam Paradise Massage Ltd | Other services | 2022 |
| Silver Fern Security Limited | Extraterritorial | 2020 |
| Silver Fern Solutions Limited | Administrative & support | 2009 |
| Silverline National Ltd | Wholesale & retail | 2024 |
| Simple Solutions (Cambs) Ltd | Professional & scientific | 2012 |
| Sinewave Project Services Ltd | Professional & scientific | 2025 |
| SIX Films London Ltd | Information & communication | 2021 |
| SJK Technology Solutions Ltd | Information & communication | 2020 |
| Skift Consulting Limited | Professional & scientific | 2018 |
| SM Roofing & Leadwork Specialists Limited | Construction | 2025 |
| Smart City Products Limited | Manufacturing | 2018 |
| Smoked Club Ltd | Manufacturing | 2020 |
| Smyths Decorating Limited | Construction | 2007 |
| SN Thai Food 2U Ltd | Wholesale & retail | 2025 |
| Sn&Rl Ltd | Hospitality | 2023 |
| SNM Accounting Ltd | Professional & scientific | 2025 |
| Softwaredotsolutions Limited | Information & communication | 2015 |
| SOLDES2020 Limited | Wholesale & retail | 2020 |
| Sonic Logistics (Transport) Ltd | Transport & logistics | 2024 |
| Soothing Essence Massage Ltd | Other services | 2024 |
| Spare Bear Limited | Information & communication | 2019 |
| Sparky Edit Limited | Information & communication | 2014 |
| Spearsons Building Services Ltd | Construction | 2019 |
| Spearsons Ltd | Construction | 2025 |
| Spectiv Limited | Manufacturing | 2020 |
| Spoonbill Studios Limited | Information & communication | 2019 |
| Spot Films Limited | Extraterritorial | 2015 |
| Spot Post Limited | Information & communication | 2003 |
| Springfield Chicago Limited | Extraterritorial | 2013 |
| Sprogley Motorsport Ltd | Manufacturing | 2025 |
| SRC Auto Care Ltd | Wholesale & retail | 2018 |
| ST Rigging Ltd | Construction | 2021 |
| ST. George Consultants Ltd | Information & communication | 2002 |
| ST. George's Tyres Limited | Wholesale & retail | 2023 |
| ST. Georges Machinery Limited | Administrative & support | 2015 |