| Stocks Place Management Company Limited | Administrative & support | 2006 |
| Stoken Management Company Limited | Real estate | 1993 |
| Stone Barton Property Limited | Real estate | 2024 |
| Stone White Investments Limited | Real estate | 2024 |
| Stonesolid Construction Limited | Construction | 2024 |
| Stonnall Care Limited | Health & social care | 2006 |
| Stora Solutions Limited | Professional & scientific | 2025 |
| Storegroup Limited | Real estate | 2000 |
| Storynestuk Ltd | Information & communication | 2026 |
| Stowmarket Care Limited | Health & social care | 2026 |
| Stowmarket Property Limited | Real estate | 2026 |
| Strada Prestazioni Ltd | Other services | 2024 |
| Straightaway Decorators Ltd | Construction | 2018 |
| Straightline Capital Limited | Financial services | 2025 |
| Strangef.O.L.K LLP | | 2007 |
| Strata House (High Wycombe) Management Company Limited | Real estate | 2017 |
| Strategic Property Group Ltd | Real estate | 2016 |
| Strategic Technology Consulting Ltd | Information & communication | 2017 |
| Stratpilot Ltd | Information & communication | 2023 |
| Strawberry Investments 2024 Limited | Professional & scientific | 2024 |
| Stress Group Holdings Limited | Financial services | 2023 |
| Stress Group Limited | Financial services | 2024 |
| Stress Management Society | Other services | 2005 |
| Strong Spoon Co Ltd | Manufacturing | 2026 |
| Strong X Group Ltd | Construction | 2025 |
| Structural Repairs & Specialist Services Limited | Construction | 1992 |
| Structuralis Limited | Manufacturing | 2025 |
| Struxify Ltd | Construction | 2024 |
| STS Distribution Limited | Wholesale & retail | 2007 |
| Stuart House Management (Ponders END) Limited | Households | 1992 |
| Stuart Wilkinson Tennis Ltd | Arts & recreation | 2025 |
| Studio 248 Ltd | Professional & scientific | 2022 |
| Studio Arch Ltd | Professional & scientific | 2025 |
| Studio Art by Bubu Ltd | Manufacturing | 2025 |
| Studio DE 3 Limited | Professional & scientific | 2013 |
| Studio Red Kite Ltd | Professional & scientific | 2023 |
| Studio Virdi Ltd | Information & communication | 2022 |
| Study Abroad Connections Ltd | Professional & scientific | 2024 |
| Stultz Technology Ltd | Information & communication | 2026 |
| Sturdy Media Ltd | Information & communication | 2018 |
| Style Dynamics Ltd | Wholesale & retail | 2010 |
| Stylephobia Ltd | Information & communication | 2026 |
| Styler Solutions Limited | Manufacturing | 2025 |
| Stylish Pentagon - Unipessoal Ltd | Professional & scientific | 2022 |
| Suave Rentals Limited | Administrative & support | 2020 |
| Subam Investors Ltd | Real estate | 2024 |
| Subas International Ltd | Real estate | 2021 |
| Subcontractor Ltd | Manufacturing | 2024 |
| Subhan Foods & Catering Ltd | Hospitality | 2025 |
| Success Waves Ltd | Administrative & support | 2014 |
| Suchy Driving Ltd | Transport & logistics | 2014 |
| Suganthy Consultancy PVT Ltd | Professional & scientific | 2026 |
| Suggi & Suggi Finance Solutions Limited | Financial services | 2023 |
| Suiceflora Limited | Wholesale & retail | 2005 |
| Suijin Limited | Real estate | 2013 |
| Sukh Traders Ltd | Wholesale & retail | 2019 |
| Sukhavati Ltd | Real estate | 2024 |
| Sukhdeep Haulage Ltd | Transport & logistics | 2025 |
| Sultans Scooters Ltd | Administrative & support | 2025 |
| Summertone Limited | Manufacturing | 1989 |
| Summit Engineering Services Ltd | Professional & scientific | 2026 |
| Summoner's Stash TCG Ltd | Wholesale & retail | 2026 |
| Sumuk Media Ltd | Professional & scientific | 2024 |
| Sun Pharma Holdings UK Limited | Financial services | 1995 |
| Sun Pharma UK Limited | Wholesale & retail | 1994 |
| Sunbury Car Sale Ltd | Wholesale & retail | 2026 |
| Sundowner VFX Ltd | Information & communication | 2022 |
| Sunex Energy Limited | Energy | 2025 |
| Sunfaiz Ltd | Health & social care | 2012 |
| Sunflare Ltd | Real estate | 2015 |
| Sunlight @ Depth Limited | Construction | 2008 |
| Sunny Aseri Limited | Construction | 2025 |
| Sunnyoaks Properties Limited | Real estate | 2021 |
| Sunnyside Care Homes Ltd | Health & social care | 2002 |
| Sunnyside UP Holdings Limited | Professional & scientific | 2016 |
| Sunray Beauty Lounge Limited | Other services | 2022 |
| Sunrise Developers Ltd | Construction | 2014 |
| Sunrise Travel Meet & Assist Heathrow Ltd | Professional & scientific | 2014 |
| Sunshine Chauffeurs Ltd | Transport & logistics | 2026 |
| Suntory Monozukuri Expert Europe Limited | Professional & scientific | 2020 |
| Sunzfame Ltd | Households | 2019 |
| Super Berry Ltd | Wholesale & retail | 2022 |
| Super Cups Ltd | Manufacturing | 2023 |
| Super CUT Ltd | Health & social care | 2014 |
| Supernova Data Solutions Limited | Information & communication | 2024 |
| Supero Group Ltd | Financial services | 2017 |
| Supersonic Media Limited | Arts & recreation | 2015 |
| Support Care Ltd | Administrative & support | 2021 |
| Support for Affluent Scholars Ltd | Health & social care | 2017 |
| Support Hub Services Ltd | Health & social care | 2025 |
| Supreme Facilities Ltd | Hospitality | 2022 |
| Sure Recycling Ltd | Water & waste | 2026 |
| Surefire Heating and GAS Services Limited | Construction | 2020 |
| Surehost Limited | Information & communication | 2003 |
| Surespeed Courier Systems Limited | Transport & logistics | 2005 |
| Surgicalfilm Ltd | Information & communication | 2013 |
| Surgiqual Ltd | Health & social care | 2024 |
| Surosh & Co Accountants Ltd | Professional & scientific | 2024 |
| Surrey Bars Ltd | Real estate | 2025 |
| Surrey PA Ltd | Administrative & support | 2019 |