| Stonecrest Group Limited | Financial services | 2025 |
| Stonecrest Properties Limited | Real estate | 2025 |
| Stonegate Windows Ltd | Administrative & support | 2023 |
| Stoner Associates Limited | Administrative & support | 2008 |
| Stop Lock Apartments RTM Company Limited | Households | 2022 |
| Stormdog Limited | Information & communication | 1999 |
| Storyhunter Limited | Information & communication | 2019 |
| Storyline Studio Ltd | Administrative & support | 2025 |
| Stovart Limited | Professional & scientific | 1997 |
| STR Installations Ltd | Construction | 2011 |
| Straightpath Consultancy Ltd | Professional & scientific | 2025 |
| Strand Systems Limited | Manufacturing | 1987 |
| Strategic Bridge Ltd | Professional & scientific | 2026 |
| Stratos Strategic Ltd | Professional & scientific | 2025 |
| Stratsmore Wills & Trust Ltd | Professional & scientific | 2014 |
| Stratum Business Services Limited | Administrative & support | 2009 |
| Stream Douglas Limited | Administrative & support | 2017 |
| Strength Physiotherapy Ltd | Health & social care | 2025 |
| Strike Properties London Ltd | Real estate | 2026 |
| STRIVE4 Academy Trust | Education | 2017 |
| Strix Surveying Ltd | Professional & scientific | 2026 |
| Stroica Construction Ltd | Construction | 2024 |
| Stroked Media Limited | Information & communication | 2018 |
| Strowger Trust Original Films Ltd | Arts & recreation | 2020 |
| Stryton Limited | Professional & scientific | 2017 |
| Stuart Plant Setbuilding Limited | Manufacturing | 2013 |
| Stuart Simons Productions Ltd | Arts & recreation | 2023 |
| Studio 11 Design Ltd | Real estate | 2001 |
| Studio 11 Development Ltd | Real estate | 2010 |
| Studio House Sidcup Limited | Construction | 2016 |
| Studio Peascod Ltd | Arts & recreation | 2015 |
| Studio School Ltd | Professional & scientific | 2022 |
| Studio Spaces Limited | Professional & scientific | 2008 |
| Study Solutions Global Ltd | Education | 2025 |
| Studylon Ltd. | Education | 2014 |
| Style Shoes Limited | Wholesale & retail | 2019 |
| Style With Love Limited | Wholesale & retail | 2025 |
| Stylezz Limited | Wholesale & retail | 2024 |
| Sub-Zero Projects Ltd | Construction | 2014 |
| Suburban Jungle Limited | Administrative & support | 2005 |
| Success IS UN Limited | Administrative & support | 2017 |
| Suexcel Properties Ltd | Real estate | 2012 |
| Suffolk Performing Arts LLP | | 2026 |
| Sufra Consultancy Limited | Information & communication | 2024 |
| Sukari Kane Ltd | Wholesale & retail | 2024 |
| Sullivan and Co Services Ltd | Construction | 2020 |
| Sultan Solutions Ltd | Information & communication | 2024 |
| Sumark Construction Ltd | Construction | 2023 |
| Sunflowers Splendid Gardens Limited | Administrative & support | 2019 |
| Sunrise 2025 Ltd | Energy | 2025 |
| Sunrisetechnologies.Co.Uk Limited | Information & communication | 2004 |
| Sunrose Investments Limited | Professional & scientific | 2009 |
| Sunrose Property Limited | Real estate | 2005 |
| Sunset Duvet Limited | Real estate | 2025 |
| Supadupa Ltd. | Wholesale & retail | 2015 |
| Super Projects Global Limited | Professional & scientific | 2021 |
| Super Repair Group Limited | Wholesale & retail | 2020 |
| Superattico Ltd | Wholesale & retail | 2022 |
| Superflex Services Ltd | Administrative & support | 2026 |
| Superlative Collective Ltd | Wholesale & retail | 2022 |
| Supershare Limited | Construction | 2006 |
| Suppliedbydilz Ltd | Wholesale & retail | 2020 |
| Supply Talent Ltd | Administrative & support | 2023 |
| Support Companions Ltd | Health & social care | 2024 |
| Supreme Exhibitions Limited | Other services | 2004 |
| Supreme Fabrica Ltd | Wholesale & retail | 2025 |
| Supreme Glazing Limited | Wholesale & retail | 2009 |
| Supreme Halal Meat Limited | Wholesale & retail | 2015 |
| SUR Catering Ltd | Hospitality | 2017 |
| Suraj Investments LLP | | 2017 |
| Suraj Ventures Limited | Wholesale & retail | 2024 |
| Surcom Consulting Limited | Professional & scientific | 2017 |
| Surecomp Business Solutions Limited | Information & communication | 2000 |
| Surevent Limited | Construction | 2008 |
| Surgeflow Growth Ltd | Professional & scientific | 2024 |
| Surmount Academy Limited | Education | 2019 |
| Surrgical Plastering and Renovation Ltd | Construction | 2025 |
| Susesco Ltd | Professional & scientific | 2016 |
| Sustainable Skin Limited | Other services | 2026 |
| Suttons Group PLC | Professional & scientific | 1976 |
| Suzy Hoodless Limited | Professional & scientific | 2003 |
| Svetalex Limited | Construction | 2023 |
| SVG Carpenter Ltd | Construction | 2019 |
| Swan Upholstery Limited | Administrative & support | 2003 |
| Swanbrae Limited | Construction | 1970 |
| Swanslow Mediation Ltd | Other services | 2025 |
| Swarling Events Ltd | Administrative & support | 2024 |
| Swarohi Limited | Administrative & support | 2012 |
| Sweet and White Limited | Administrative & support | 2024 |
| Sweet Cane Ltd | Wholesale & retail | 2026 |
| Sweet Table Boutique Ltd | Wholesale & retail | 2016 |
| Sweetpea's Factory Limited | Administrative & support | 2021 |
| Swift Home Developments Ltd | Construction | 2020 |
| Swift Inventory Limited | Real estate | 2017 |
| Swimfortri Limited | Other services | 2003 |
| Switch Tech Talent Ltd | Administrative & support | 2023 |
| Switchwire Limited | Extraterritorial | 2012 |
| Sydmilden Limited | Professional & scientific | 2018 |
| SYL Construction & Development Ltd | Construction | 2018 |
| Sylheti Restaurant Limited | Hospitality | 2026 |