| Rozzy Prior Livery Limited | Other services | 2025 |
| RR Marshall Electrical Services Ltd | Construction | 2026 |
| RS Business Connections Ltd | Wholesale & retail | 2012 |
| RSL Cambridge Ltd | Construction | 2012 |
| Ruby and Rose ELY Ltd | Wholesale & retail | 2018 |
| Rukure Ltd | Health & social care | 2022 |
| Runners and Rugs Ltd | Manufacturing | 2023 |
| Ruocco Automotive Ltd | Wholesale & retail | 2026 |
| Russell and Russell Properties Limited | Real estate | 2003 |
| Russell Paddock Limited | Extraterritorial | 2019 |
| Rust Farm Restorers Ltd | Wholesale & retail | 2025 |
| Rutland Water Estates Ltd | Hospitality | 2025 |
| S & Y Haulage Limited | Information & communication | 2005 |
| S and T Transport Services (Newmarket) Limited | Transport & logistics | 1986 |
| S F Entertainment Ltd | Administrative & support | 2025 |
| S G S Associates Limited | Construction | 2010 |
| S Goode Roofing Ltd | Construction | 2021 |
| S I (Soroptimist International) Limited | Other services | 2013 |
| S J Ball Brickwork Ltd | Manufacturing | 2020 |
| S J Murfitt Carpentry Ltd | Construction | 2018 |
| S K Ward Pest Control Ltd | Administrative & support | 2010 |
| S L Mires Brick and Block Haulage Ltd | Transport & logistics | 2011 |
| S M Righton Ltd | Arts & recreation | 2025 |
| S P Smith Carpentry and Building Limited | Administrative & support | 2017 |
| S R Russell Properties Ltd | Real estate | 2022 |
| S&J Franklin Ltd | Real estate | 2023 |
| S&Jb Property Limited | Real estate | 2019 |
| S. & G. Car Repairs (2018) Ltd | Wholesale & retail | 2018 |
| S.H.P. Engineering Ltd. | Manufacturing | 1994 |
| S3M Property Services Limited | Real estate | 2022 |
| S7 Rail Solutions Ltd | Construction | 2019 |
| Sadale Limited | Professional & scientific | 2006 |
| Safe & Sure Limited | Information & communication | 2023 |
| Safe Futures Collective Ltd | Education | 2024 |
| Safety First Scaffolding Services Ltd | Construction | 2020 |
| Sage Consultancy Limited | Professional & scientific | 2007 |
| Sail View Management Company Limited | Households | 2021 |
| Salads Harvesting Services Limited | Agriculture & fishing | 2015 |
| Salmac Ltd | Extraterritorial | 2021 |
| Salmons Brothers Limited | Manufacturing | 1992 |
| Salmons Group Limited | Financial services | 2022 |
| Samis Hairdressers Limited | Other services | 2019 |
| Sand Consultants Ltd | Professional & scientific | 2007 |
| Sandfields Farms Limited | Agriculture & fishing | 2007 |
| Sandra Miller Accounting Limited | Professional & scientific | 2017 |
| Sapco Investments Ltd | Administrative & support | 2016 |
| SAPCO2 Ltd | Financial services | 2016 |
| Sarah Julian Hair Design Ltd | Other services | 2018 |
| Sarah Tindall Limited | Other services | 2006 |
| Sarahs Pet Care Cambs Ltd | Agriculture & fishing | 2024 |
| Sarkin Limited | Transport & logistics | 2019 |
| Saturn Sports Limited | Wholesale & retail | 2012 |
| Saunders Brothers Developments Limited | Extraterritorial | 2016 |
| Saville Solver Limited | Professional & scientific | 2005 |
| Saving Grace Recruitment Limited | Administrative & support | 2019 |
| Saxby Decorating Ltd | Construction | 2022 |
| Saxon Estate Management Company Limited | Real estate | 2004 |
| Saxon Stoves Ltd | Transport & logistics | 2013 |
| SB Bubble Tea Limited | Hospitality | 2025 |
| Scaffold Rent and Lease Ltd | Administrative & support | 2025 |
| Scented Beauty Ltd | Wholesale & retail | 2023 |
| Science Eventz Ltd | Professional & scientific | 2018 |
| Scotia Magnum Ltd | Professional & scientific | 2026 |
| Scott Brothers Anglia Limited | Wholesale & retail | 2002 |
| Scott Cleaning Services Limited | Administrative & support | 2017 |
| Scottys Little Soldiers Trading Ltd | Wholesale & retail | 2011 |
| Screenlooker Productions Limited | Professional & scientific | 2025 |
| Screenprint (Cambridge) Ltd. | Manufacturing | 1983 |
| Scuderia Giocri Limited | Agriculture & fishing | 2012 |
| Sculthorpe Brothers Limited | Professional & scientific | 2014 |
| Sculthorpe Construction Limited | Extraterritorial | 2021 |
| Seahorse Aquatic Training Ltd | Education | 2025 |
| Seahorse Swim School Ltd | Arts & recreation | 2014 |
| Seal Pups Sensory Swim School Ltd | Education | 2024 |
| Sealion Swimming Pools and Spa's Limited | Construction | 2005 |
| Sealy Builders Limited | Construction | 2016 |
| Seatonhurst Land Ltd | Real estate | 2026 |
| Seatonhurst Limited | Construction | 2016 |
| Seats U.K. Ltd | Other services | 2018 |
| Sector Zero Ltd | Professional & scientific | 2025 |
| Secure Storage ELY Ltd | Information & communication | 2022 |
| Secure Your Farm Limited | Information & communication | 2013 |
| Securemark Ltd | Information & communication | 2023 |
| Sedgeway Associates Limited | Real estate | 2014 |
| Sedgeway Business Park Limited | Real estate | 2014 |
| Seede Ltd | Wholesale & retail | 2024 |
| Selfwork Ltd | Wholesale & retail | 2022 |
| Selmarc Limited | Administrative & support | 2017 |
| Semaj (ELY) Limited | Construction | 2014 |
| Sensor Networks Ltd | Information & communication | 2017 |
| Sentinel Roof Consultants Ltd | Construction | 2023 |
| Seoul Property Ltd | Real estate | 2024 |
| SEQ Solutions Ltd | Professional & scientific | 2022 |
| SERO27 Ltd | Hospitality | 2025 |
| SEW Much to DO Ltd | Wholesale & retail | 2012 |
| Seymours Paddock Management Company Limited | Households | 2017 |
| SF Accounting Limited | Professional & scientific | 2004 |
| SGM Co. Demolition & Groundworks Ltd | Construction | 2023 |
| Shacklewell Road Management Company Limited | Real estate | 2012 |
| Shane White Plant Hire & Groundworks Ltd | Construction | 2017 |