| Stoneegreen Limited | Transport & logistics | 2025 |
| Stoneforce Paving Ltd | Construction | 2015 |
| Stonemans Pallet Services Ltd | Wholesale & retail | 2021 |
| Stopsley Baptist Church | Other services | 2011 |
| Stopsley Court Limited | Households | 2005 |
| Stopsley Fish Bar Ltd | Hospitality | 2022 |
| Stopslye Hand Car Wash Ltd | Other services | 2024 |
| Storm Fiber Limited | Construction | 2026 |
| Storm Gym Ltd | Arts & recreation | 2010 |
| Storm London Ltd | Wholesale & retail | 2021 |
| Storm Motor Werks Limited | Wholesale & retail | 2013 |
| Storm of London Limited | Wholesale & retail | 1993 |
| Storm UK Limited | Extraterritorial | 1993 |
| Stormgymuk Ltd | Other services | 2021 |
| Storms Security Ltd | Financial services | 2026 |
| Storybest Entertainment Limited | Information & communication | 2025 |
| Stotfold Pizza Limited | Hospitality | 2025 |
| Stow Consultancy Ltd | Information & communication | 2021 |
| STP Equipment Limited | Manufacturing | 2007 |
| Stpendrobay Limited | Health & social care | 2019 |
| Strada Automotive Solutions Ltd | Wholesale & retail | 2019 |
| Straffan Homes Limited | Construction | 2005 |
| Strafford Close Management Company Limited | Households | 1998 |
| Straight Down the Line Limited | Real estate | 2002 |
| Straight Path Properties Ltd | Real estate | 2023 |
| Straightline Construction Limited | Construction | 2016 |
| Stramax Industries Limited | Construction | 2021 |
| Strand Creative Hair Design Limited | Other services | 2011 |
| Strata Conversion Co. Ltd | Professional & scientific | 2026 |
| Stratamed Solutions Ltd | Health & social care | 2026 |
| Stratara Ltd | Information & communication | 2026 |
| Strategy and Dreams Ltd | Construction | 2023 |
| Stratiform Consulting Group Limited | Professional & scientific | 2025 |
| Stratis Studios Ltd | Manufacturing | 2025 |
| Straton Group Ltd | Wholesale & retail | 2020 |
| Stratton & Co.(Plastics)Limited | Real estate | 1971 |
| Stratton Motors Ltd | Wholesale & retail | 2019 |
| Street Fathers Luton CIC | Health & social care | 2025 |
| Street Food Junction Ltd | Hospitality | 2022 |
| Streetz Runner Ltd | Transport & logistics | 2019 |
| Strictly Entertainment Limited | Hospitality | 2016 |
| Strictly Food Limited | Hospitality | 2016 |
| String Properties Ltd | Real estate | 2011 |
| Stringcutters Ltd | Arts & recreation | 2025 |
| Strive Space Limited | Real estate | 2026 |
| Stroheim Capital Ltd | Transport & logistics | 2010 |
| Strong Soul Fitness CIC | Arts & recreation | 2023 |
| Strong Suits Va's Limited | Administrative & support | 2016 |
| Strong Tower 7TH Day Church of GOD | Other services | 2015 |
| Strong Tower Basic School | Education | 2011 |
| Strong Tower Day Nursery Limited | Education | 2022 |
| Strong Tower Nursery Limited | Education | 2017 |
| Strong Tower Pre-School Limited | Education | 2020 |
| Strongbase Ltd. | Transport & logistics | 2010 |
| STS Design & Construction PVT Ltd | Construction | 2012 |
| STS Guarding Services Limited | Administrative & support | 2021 |
| STS Properties Limited | Real estate | 1990 |
| STS Supermarket Ltd | Wholesale & retail | 2021 |
| Stsa Ltd | Real estate | 2025 |
| Stuart Tompkins Plant Hire Limited | Construction | 2006 |
| Stuart's Bakery Limited | Wholesale & retail | 2025 |
| Stud Retail Ltd | Extraterritorial | 2023 |
| Studio 10 Barbers Ltd | Other services | 2024 |
| Studio 56 Limited | Professional & scientific | 2012 |
| Studio Classic Limited | Administrative & support | 2015 |
| Studio Gabellini-Fava Ltd | Arts & recreation | 2024 |
| Studio INK PVT Ltd | Professional & scientific | 2022 |
| Studio Salomaa Ltd | Administrative & support | 2025 |
| Studio Trendz Ltd | Wholesale & retail | 2025 |
| STUDIO8 Brands Ltd | Professional & scientific | 2025 |
| Study Leap Ltd | Administrative & support | 2024 |
| Study Town Limited | Education | 2024 |
| Study UK Europe Ltd | Education | 2019 |
| Stuffgridd Ltd | Wholesale & retail | 2026 |
| Stun Buy Ltd | Real estate | 2023 |
| Style Corp. Ltd | Professional & scientific | 2020 |
| Stylez Barbers Limited | Other services | 2025 |
| Stylus Promotions Limited | Hospitality | 2010 |
| Sualch Company Limited | Health & social care | 2014 |
| Sub-Cnc Precision Ltd | Manufacturing | 2008 |
| Subeia Ltd | Wholesale & retail | 2020 |
| Sublime Events UK Ltd | Professional & scientific | 2023 |
| Sublime Tech Consulting Ltd | Hospitality | 2023 |
| Submittax Limited | Professional & scientific | 2024 |
| Subraa Limited | Wholesale & retail | 2025 |
| Subvert Limited | Administrative & support | 2015 |
| Subway Limited | Construction | 2024 |
| Success Intelligence Ltd | Administrative & support | 1996 |
| Success Makers Education Limited | Education | 2017 |
| Such Clarity Limited | Information & communication | 2023 |
| Suckamount Ltd | Manufacturing | 2025 |
| Sud-Med Investments Ltd | Real estate | 2025 |
| Sud-Med Limited | Health & social care | 2023 |
| Sudhozai Traders Limited | Wholesale & retail | 2025 |
| SUE Services Ltd | Health & social care | 2025 |
| Sugar Cane 2018 Ltd | Hospitality | 2018 |
| Sugu Park and FLY Ltd | Hospitality | 2022 |
| Sugums Ltd | Professional & scientific | 2014 |
| Suite Property Management Ltd | Real estate | 2021 |
| Suitsmeuk Limited | Wholesale & retail | 2025 |