| SMS Aero Limited | Administrative & support | 2006 |
| SMT GB Tractors Ltd | Wholesale & retail | 2016 |
| SMW Home Improvements Ltd. | Administrative & support | 2021 |
| Snackshare Ltd | Wholesale & retail | 2024 |
| Soar Advisory Ltd | Professional & scientific | 2025 |
| Soar Domestics Ltd | Construction | 2024 |
| Soar Limited | Administrative & support | 2014 |
| Soif Music Publishing Limited | Arts & recreation | 2008 |
| Solar Panels Cambs Limited | Construction | 2010 |
| Solaris Wines Ltd | Wholesale & retail | 2017 |
| Sole-Leris Design Ltd | Professional & scientific | 2013 |
| Somes Multidynamics Company Limited | Manufacturing | 2024 |
| Somor Development Services Ltd | Professional & scientific | 2024 |
| Somor Ltd | Construction | 2019 |
| Sonas World Ltd | Health & social care | 2012 |
| Sonia Woodward Rehabilitation Services Limited | Health & social care | 2009 |
| Sonnenheim Ltd | Extraterritorial | 2021 |
| Sophie Knight Translations Ltd | Professional & scientific | 2025 |
| Sortcut Ltd | Other services | 2018 |
| Souldance Ltd | Extraterritorial | 2022 |
| Souldream Ltd | Extraterritorial | 2022 |
| Sourcesmart Solutions Ltd | Administrative & support | 2023 |
| Sovatec Ltd | Construction | 2025 |
| Space Time Limited | Other services | 2013 |
| Spark Eden Limited | Real estate | 2021 |
| Special Brains Paediatric Specialist Services Ltd | Information & communication | 2019 |
| Speedwell Property Limited | Real estate | 2019 |
| Spence Mortgages Ltd | Financial services | 2025 |
| Spencer LEE Building and Maintenance Ltd | Construction | 2021 |
| Spencerforce Ltd | Administrative & support | 2021 |
| Sphere of Influence Marketing Ltd | Professional & scientific | 2025 |
| Spidermaf Industries Limited | Arts & recreation | 2026 |
| Sports Integrity Services Limited | Professional & scientific | 2012 |
| Springclean (Cambs) Limited | Administrative & support | 2014 |
| Square Builders Limited | Construction | 2018 |
| Squeeze & Slice Ltd | Manufacturing | 2025 |
| Squire Property Lettings Limited | Real estate | 2023 |
| Squirrelsaurus Ltd | Information & communication | 2018 |
| Srinivasa Fuels Ltd | Wholesale & retail | 2021 |
| SS Facilities Limited | Hospitality | 2025 |
| SS Properties Ltd | Real estate | 2006 |
| SSB Analytics Ltd | Professional & scientific | 2020 |
| ST Neots African Shop Ltd | Wholesale & retail | 2025 |
| ST Neots Chiropractic Clinic Limited | Health & social care | 2014 |
| ST Neots Coffee Company Limited | Administrative & support | 2013 |
| ST Neots Fireplace & Stove Centre Limited | Wholesale & retail | 2011 |
| ST Neots Foot & Health Clinic Ltd | Health & social care | 2019 |
| ST Neots Golf Club (Trading) Company Limited | Hospitality | 2018 |
| ST Neots Initiative Community Interest Company | Other services | 2025 |
| ST Neots Legal Service Ltd | Professional & scientific | 2025 |
| ST Neots MAN Cave CIC | Other services | 2022 |
| ST Neots Pet Care Services Ltd | Professional & scientific | 2019 |
| ST Neots Plastering Limited | Construction | 2018 |
| ST Neots Print Limited | Wholesale & retail | 2014 |
| ST Neots Rugby Union Football Club Ltd | Arts & recreation | 2019 |
| ST Neots Service Limited | Wholesale & retail | 2019 |
| ST Neots TAI CHI Academy Limited | Health & social care | 2022 |
| ST Nicholas Court (Sheringham) Management Ltd | Real estate | 2023 |
| ST Nicholas Service Management Limited | Households | 2025 |
| ST Todorov Ltd | Construction | 2024 |
| St&St London UK Ltd | Wholesale & retail | 2022 |
| ST. Andrew's Court (Huntingdon) Management Company Limited | Households | 1986 |
| ST. Neots English Centre Limited | Education | 2014 |
| ST. Neots Golf Club Ltd | Arts & recreation | 2017 |
| ST. Neots Home Improvements Limited | Construction | 2020 |
| ST. Neots Self Storage Limited | Extraterritorial | 2013 |
| ST. Neots Town Football Club Ltd. | Arts & recreation | 1994 |
| Stable Cables Electrical Ltd | Construction | 2019 |
| Stafferton Capital Funding 1 Limited | Financial services | 2023 |
| Stafferton Capital Funding 2 Limited | Financial services | 2024 |
| Stafferton Capital Funding 3 Limited | Financial services | 2024 |
| Stafferton Capital Limited | Professional & scientific | 2022 |
| Stafferton Investments Ltd | Financial services | 2019 |
| Stageworks Studios Ltd | Arts & recreation | 2005 |
| Stand Consulting Limited | Professional & scientific | 2022 |
| Star Installations Limited | Construction | 1980 |
| Star Unique Company Ltd | Wholesale & retail | 2022 |
| Statscloud Ltd | Information & communication | 2025 |
| Stecol Ltd | Construction | 2023 |
| Steinkrug Publications Limited | Information & communication | 1995 |
| Stellaform Ltd | Wholesale & retail | 2024 |
| Stellar Surfacing Ltd | Construction | 2022 |
| Stenic Limited | Construction | 1976 |
| Step & Stitch Trading Ltd | Wholesale & retail | 2025 |
| Step DEV Limited | Information & communication | 2016 |
| Stepping OUT Foot Care Ltd | Health & social care | 2025 |
| Steps to Safety Ltd | Professional & scientific | 2026 |
| Sterling Ledgers Limited | Professional & scientific | 2025 |
| Sterns Asset Management Limited | Real estate | 2023 |
| Stewline Limited | Professional & scientific | 2013 |
| Still Lifting Ltd | Construction | 2017 |
| Still Motion Limited | Professional & scientific | 2016 |
| Stobbs Consulting Ltd | Financial services | 2018 |
| Stockport Eats Ltd | Hospitality | 2021 |
| Stocks Away Limited | Wholesale & retail | 2011 |
| Stockwell Roofing Ltd | Construction | 2023 |
| Store IT Centre Ltd | Administrative & support | 2012 |
| Storm Bay Developments Limited | Construction | 2014 |
| Straw HAT Communications Ltd | Professional & scientific | 2020 |
| Street Food Fest Ltd | Hospitality | 2021 |