| Starseed Global Ltd | Information & communication | 2024 |
| Startpoint Training & Consulting Ltd | Professional & scientific | 2025 |
| Starz Records Limited | Information & communication | 2019 |
| Starz Security Inc Limited | Administrative & support | 2020 |
| Station Food Express Limited | Wholesale & retail | 2026 |
| Station Road (Great Shelford) Management Company Limited | Households | 2016 |
| Staunton's Hill Residents (Management) Company Limited | Households | 2000 |
| Stay Away Home LLP | | 2018 |
| Staygrafting Workwear Ltd | Manufacturing | 2026 |
| Steadfast Football Holdings Ltd | Arts & recreation | 2025 |
| Stean Enterprises Ltd | Wholesale & retail | 2011 |
| Stearthill House Management Limited | Households | 2018 |
| Stecagen Limited | Health & social care | 2026 |
| Stedan Consult Limited | Information & communication | 2020 |
| Stedman Scaffolding Ltd | Construction | 2024 |
| Steel Import Services Ltd | Professional & scientific | 2020 |
| Steel Sound Design Ltd | Arts & recreation | 2019 |
| Steeple Chase (Frisby) Management Company Limited | Households | 2018 |
| Stefan Michael Transport Ltd | Wholesale & retail | 2025 |
| Stefrod Limited | Transport & logistics | 2025 |
| Stefy's Tyres Ltd | Wholesale & retail | 2021 |
| Stek Solutions Ltd | Information & communication | 2026 |
| Stellander OAG Enterprise Ltd | Professional & scientific | 2013 |
| Stellar Precision Components Ltd | Manufacturing | 2018 |
| Stellarplus Care Services Limited | Health & social care | 2022 |
| Stellomartin Limited | Health & social care | 2025 |
| Step Ahead Accounting Ltd | Professional & scientific | 2025 |
| Step Services Limited | Construction | 2024 |
| Stephanie Nana Boahemaa Asante Ltd | Administrative & support | 2016 |
| Stepmagna Ltd | Professional & scientific | 2012 |
| Sterling Diesels Ltd | Manufacturing | 2018 |
| Sterling Digitech Ltd | Wholesale & retail | 2023 |
| Sterling GAS Limited | Construction | 2018 |
| Sterling J Limited | Health & social care | 2023 |
| Sterling Leathers Ltd | Wholesale & retail | 2014 |
| Sterling Mechatronics Ltd | Professional & scientific | 2018 |
| Sterling Path Ltd | Health & social care | 2024 |
| Sterling Pro Parts Ltd | Wholesale & retail | 2024 |
| Sterling Reman Ltd | Manufacturing | 2024 |
| Sterling Wholesale Limited | Wholesale & retail | 2000 |
| Stet Media Limited | Administrative & support | 2016 |
| Stethosource Ltd | Health & social care | 2025 |
| Steve NTI Ltd | Arts & recreation | 2023 |
| Steve Wallduck Steelwork Ltd | Manufacturing | 2014 |
| Steven Daniels Property Limited | Real estate | 2024 |
| Stewards Academy Trust | Education | 2011 |
| Stfrancisdepaul Group Ltd | Transport & logistics | 2017 |
| Sticcocom Ltd | Manufacturing | 2014 |
| Stickley Court (Management) Limited | Households | 2015 |
| Stillwaters Corp Ltd | Health & social care | 2022 |
| STJ Mechanical Limited | Construction | 2017 |
| Stockell Ventures Ltd | Real estate | 2015 |
| Stockus Ltd | Transport & logistics | 2015 |
| Stokes Carpentry Ltd | Construction | 2026 |
| Stone Circle Livery LLP | | 2011 |
| Stonegrove Refrigeration Services Limited | Manufacturing | 2002 |
| Stonekey Services Ltd | Real estate | 2025 |
| Stoneriver Education Limited | Education | 2016 |
| Store RR Ltd | Wholesale & retail | 2024 |
| Storeys Estates Limited | Real estate | 2025 |
| Stories Click Ltd | Information & communication | 2023 |
| Stork Interiors Ltd | Construction | 2023 |
| Storm Equestrian Ltd | Wholesale & retail | 2025 |
| Storm's Body Melt Ltd | Wholesale & retail | 2024 |
| Stormtruck Ltd | Wholesale & retail | 2015 |
| Stort Mill Recycling Ltd | Water & waste | 2012 |
| Stort Valley Enterprises Limited | Financial services | 2022 |
| Stort Valley Fencing Centre Ltd | Arts & recreation | 2021 |
| Stort Valley Spirits Limited | Wholesale & retail | 2022 |
| Stortford Body Repairs Limited | Wholesale & retail | 2015 |
| Stortford Stone Ltd | Manufacturing | 2025 |
| Stortvalley.Com Limited | Financial services | 1999 |
| Stow Quill Limited | Manufacturing | 2024 |
| Stowtech Ltd | Construction | 2017 |
| Straining Nets Limited | Health & social care | 2023 |
| Strasse Innovativ Ltd | Information & communication | 2025 |
| Strata Terrace Management Company Limited | Households | 2015 |
| Stratoswealth Limited | Financial services | 2025 |
| Strayham Limited | Professional & scientific | 2014 |
| STREETS2HOMES | Hospitality | 2007 |
| Strike Group Ltd | Arts & recreation | 2023 |
| Studio 10 Media Ltd | Information & communication | 2023 |
| Studio Akram Ltd | Administrative & support | 2018 |
| Studio Go Go Limited | Information & communication | 2018 |
| Studio Heroes Ltd | Professional & scientific | 2024 |
| Studio JET Limited | Arts & recreation | 2024 |
| Studio KMC Architects Ltd | Professional & scientific | 2022 |
| Study Hayes Management Company Limited | Households | 2018 |
| Stunning Gardens Ltd | Administrative & support | 2025 |
| Style Barbers Harlow Ltd | Other services | 2023 |
| Stylead Limited | Wholesale & retail | 2015 |
| Stylen UK Ltd | Wholesale & retail | 2021 |
| Stylex Party Ltd | Wholesale & retail | 2011 |
| Sublimis Limited | Professional & scientific | 2016 |
| Subomi Styles Limited | Wholesale & retail | 2021 |
| Subru's Store Ltd | Wholesale & retail | 2019 |
| Success Electronics Limited | Wholesale & retail | 2022 |
| Success Supplementary School & After-School Club Ltd | Health & social care | 2024 |
| SUE Harris Corporation Limited | Hospitality | 1999 |
| Sugarpalm Properties Ltd | Real estate | 2020 |