| Steel Wilkins Ltd | Other services | 2023 |
| Steele Fayre Limited | Hospitality | 2019 |
| Stefan Ionescu Limited | Transport & logistics | 2017 |
| Stefi Development Ltd | Construction | 2026 |
| Stella Alexandra Edwards Ltd | Extraterritorial | 2022 |
| Stella Maris Solicitors LLP | | 2009 |
| Step Office Limited | Real estate | 2021 |
| Stepping Stone Pubs Ltd | Hospitality | 2019 |
| Steps Ahead Nursery Limited | Education | 2000 |
| Stepzero.Eco CIC | Information & communication | 2026 |
| Sterling Cars Limited | Transport & logistics | 1996 |
| Sterling Rentals Limited | Real estate | 2020 |
| Sterling Shave Club Ltd. | Wholesale & retail | 2013 |
| Steve Benson Farming Limited | Agriculture & fishing | 1981 |
| Steve Frenchie Ltd | Wholesale & retail | 2025 |
| Steve Windel Landscaping Ltd | Administrative & support | 2015 |
| Steven Cottee Services Limited | Manufacturing | 2005 |
| Stevenage Business Park Management Limited | Real estate | 2003 |
| Stevenage Electric Forecourt Ltd | Energy | 2016 |
| Stewart Eldon Associates Ltd | Professional & scientific | 2010 |
| Stewart.Toplis-Engineering-Services Ltd | Wholesale & retail | 2022 |
| Stewart’S Medical Couriers Ltd | Transport & logistics | 2024 |
| STG Panel & Paint Ltd | Wholesale & retail | 2024 |
| Stg-Uk Limited | Information & communication | 2011 |
| Stickman Ltd | Wholesale & retail | 2016 |
| Stimulus Consulting Limited | Professional & scientific | 2005 |
| Stiubi Ltd | Transport & logistics | 2025 |
| Stockers Catering Ltd | Hospitality | 2022 |
| Stockham Gardens Management Company Limited | Households | 2007 |
| Stokes Developments Ltd | Construction | 2026 |
| Stonar Property Services Ltd | Construction | 2018 |
| Stone Cottages Limited | Real estate | 2020 |
| Stonecrest Property Development Ltd | Construction | 2025 |
| Stonehanger Flats Management Company (Salcombe) Limited | Administrative & support | 1984 |
| Stonelea (Purton) Estate Management Company Limited | Extraterritorial | 2012 |
| Stonelear Limited | Construction | 2014 |
| Stoneline Construction LLP | | 2021 |
| Stones Painting and Decorating Limited | Construction | 2026 |
| Stor-Rite Services Limited | Wholesale & retail | 2012 |
| Storage Eleven Limited | Construction | 2025 |
| Storehouse Financial Solutions Ltd | Professional & scientific | 2023 |
| STOREIT4ME Limited | Transport & logistics | 2021 |
| Storm Facilities Management Limited | Administrative & support | 2013 |
| Storm Recruitment (Swindon) Ltd | Administrative & support | 2015 |
| Storm Recruitment Trustee Ltd | Professional & scientific | 2025 |
| Stornord (Avonmouth) Ltd | Financial services | 2025 |
| Stornord Ltd | Financial services | 2025 |
| Stotram Limited | Wholesale & retail | 2017 |
| Stourbridge Coaching LLP | | 2018 |
| Strang & Co Property Limited | Professional & scientific | 2022 |
| Strange Oak Limited | Administrative & support | 2016 |
| Strategic Air Services Limited | Manufacturing | 2016 |
| Strategic Business Management Solutions Ltd | Professional & scientific | 2023 |
| Strategic Maintenance Planning Holdings Limited | Financial services | 2019 |
| Strategic Maintenance Planning Limited | Information & communication | 1996 |
| Strategic Reward Solutions Ltd | Professional & scientific | 2008 |
| Stratford Dental Centre Limited | Health & social care | 2010 |
| Stratone Court Management Limited | Households | 1987 |
| Stratsos Services Limited | Administrative & support | 2015 |
| Stratton Apartments Ltd | Households | 2020 |
| Stratton Care Services Limited | Health & social care | 2026 |
| Stratton Catering Ltd | Wholesale & retail | 2015 |
| Stratton Juniors Football Club 2020 Ltd | Education | 2020 |
| Stratton Park Holdings Ltd | Professional & scientific | 2019 |
| Stratton Park Ltd | Real estate | 1985 |
| Stratton Products Limited | Wholesale & retail | 2013 |
| Stratton Saffron Limited | Hospitality | 2015 |
| Strauther LLP | | 2013 |
| Streamline Financial Ltd | Financial services | 2023 |
| Strength With Sarah Ltd | Arts & recreation | 2025 |
| Stride 360 Limited | Education | 2023 |
| Stronach Martial Arts Support Ltd | Arts & recreation | 2023 |
| Strong Tower Estate Ltd | Real estate | 2023 |
| Stronghold Global Limited | Wholesale & retail | 2012 |
| Stroud Foot Clinic Limited | Health & social care | 2019 |
| Stroud Real Estate Ltd | Real estate | 2023 |
| Structural Timber Association Limited | Other services | 1999 |
| Stuani Martins Ltd | Wholesale & retail | 2022 |
| Stuart Barnard Ltd | Administrative & support | 2020 |
| Studio 365 Limited | Information & communication | 2025 |
| Studio 5 Serviced Accommodation Ltd | Real estate | 2025 |
| Studio 64 Limited | Wholesale & retail | 2021 |
| Studio a Architecture Ltd | Professional & scientific | 2026 |
| Studio Air Limited | Arts & recreation | 2023 |
| Studio GUS Ltd | Information & communication | 2026 |
| Studio Nails Ltd | Other services | 2021 |
| Studio Ruibin Limited | Professional & scientific | 2021 |
| Studio Yala Limited | Information & communication | 2024 |
| Studiobrows Beauty & Academy Ltd | Other services | 2021 |
| Studley Grange Ltd | Arts & recreation | 2018 |
| Study LAB Ltd | Education | 2019 |
| Style Generation Ltd | Other services | 2026 |
| Style Green Ltd | Transport & logistics | 2023 |
| Su-Sushi Limited | Hospitality | 2014 |
| Sublime Engineering Ltd | Professional & scientific | 2022 |
| Subrosa Counselling Ltd | Health & social care | 2024 |
| Subtext Strategy Ltd | Professional & scientific | 2025 |
| Suburban Construction Co.Limited | Extraterritorial | 1961 |
| Success Martial Arts Ltd | Arts & recreation | 2024 |
| Sudan Information Service Ltd | Information & communication | 2021 |