| STL Commercial Ltd | Real estate | 2024 |
| STL MGT Ltd | Real estate | 2021 |
| STL Stays Ltd | Real estate | 2022 |
| STM Retail Ltd | Wholesale & retail | 2023 |
| Stobbs (IP) Ltd | Professional & scientific | 2013 |
| Stobbs Lite Limited | Professional & scientific | 2018 |
| Stockley Engineering Ltd | Manufacturing | 2016 |
| Stockmans Meadow Limited | Hospitality | 2019 |
| Stoicescu Aviation Ltd | Manufacturing | 2024 |
| Stone Bridge Property Management Limited | Real estate | 2019 |
| Stone PIG Holdings Limited | Administrative & support | 2018 |
| Stone PIG Limited | Other services | 1965 |
| Stoneapple Productions Ltd. | Administrative & support | 1998 |
| Stonecold Studios Ltd | Wholesale & retail | 2022 |
| Stonecross Investment Office Limited | Financial services | 2021 |
| Stonecross Ventures 2 Limited | Financial services | 2023 |
| Stonecross Ventures LLP | | 2021 |
| Stonefield Advisory Limited | Professional & scientific | 2018 |
| Stoneson Real Estate Ltd | Hospitality | 2024 |
| Stopwatch Communications Limited | Information & communication | 2004 |
| Storebird Storage Limited | Extraterritorial | 2025 |
| Storey's Field Community Trust | Arts & recreation | 2013 |
| Stories Event Hire Ltd | Professional & scientific | 2024 |
| Stories of Change LLP | | 2024 |
| Storm Corporate Support Limited | Administrative & support | 2016 |
| Stormsure Limited | Manufacturing | 1992 |
| Storrm Property Maintenance Ltd. | Construction | 2010 |
| Storytelling Group Limited | Professional & scientific | 2021 |
| Storytime Consulting Ltd | Arts & recreation | 2022 |
| Stracey Ltd | Hospitality | 2019 |
| Strada Imaging Ltd | Information & communication | 2019 |
| Stragglethorpe Properties Limited | Households | 2004 |
| Straight Ltd | Wholesale & retail | 2025 |
| Strand House Management Company Limited | Hospitality | 1980 |
| Strand Ventures GP Holdco Limited | Financial services | 2025 |
| Stratagem Elysium Limited | Wholesale & retail | 2025 |
| Stratagem Intellectual Property Management Limited | Professional & scientific | 1999 |
| Stratagema Advisors LLP | | 2022 |
| Stratasys Solutions Limited | Wholesale & retail | 2014 |
| Strategic Intelligence Alliance in Healthcare Limited | Information & communication | 2017 |
| Strategic Legal Advisory LLP | | 2025 |
| Strategic Technology Bioconsulting Limited | Professional & scientific | 2018 |
| Strategize and Insight Practice Limited | Professional & scientific | 2022 |
| Strategyist Limited | Professional & scientific | 2019 |
| Strategypharm Ltd | Professional & scientific | 2024 |
| Strathmore Advisers Limited | Professional & scientific | 2005 |
| Stratosm Limited | Administrative & support | 2022 |
| Stratton Community Farm C.I.C. | Education | 2009 |
| Stratum Systems Limited | Information & communication | 2026 |
| Strawberry Fair C.I.C. | Arts & recreation | 2011 |
| Strawberry Fields Enterprises Limited | Agriculture & fishing | 2014 |
| Strawberry Infotech Co., Ltd | Information & communication | 2021 |
| Stream Industries Ltd. | Administrative & support | 2022 |
| Stream Projects Limited | Information & communication | 2006 |
| Streamline Technology Ltd | Information & communication | 2023 |
| Streamly Media Ltd | Wholesale & retail | 2025 |
| Strebor Civil Engineering Ltd | Professional & scientific | 2013 |
| Street BBQ Ltd | Hospitality | 2020 |
| Street Child United | Arts & recreation | 2011 |
| Street Food Box Ltd | Administrative & support | 2020 |
| Streets Newco Limited | Financial services | 2025 |
| Strength Level Limited | Administrative & support | 2022 |
| Stretten Avenue 1970 Limited | Extraterritorial | 2014 |
| Stretten Avenue Management Limited | Households | 1995 |
| Stretten Ltd | Administrative & support | 2026 |
| Strictly Daylilies Ltd | Agriculture & fishing | 2012 |
| Strilo Ltd | Information & communication | 2012 |
| Strobe Productions Ltd | Professional & scientific | 2024 |
| Strommen UK Ltd | Manufacturing | 2013 |
| Strongwall Limited | Construction | 2024 |
| Strucco Limited | Real estate | 2025 |
| Structural Engineers Cambridge Limited | Professional & scientific | 2014 |
| Structural Learning Limited | Education | 2017 |
| Structure Restauration Ltd | Construction | 2025 |
| Structured Custom Limited | Information & communication | 2010 |
| STS Inspection & Certification Limited | Extraterritorial | 2018 |
| Stuart Darling Limited | Construction | 1997 |
| Student Accommodation Provision LLP | | 2010 |
| Student Accommodation Provision Two LLP | | 2010 |
| Student First Group Limited | Professional & scientific | 2018 |
| Students Travel Company Limited | Wholesale & retail | 2023 |
| Studio 24 Limited | Information & communication | 2000 |
| Studio 55 Architects Ltd | Professional & scientific | 2023 |
| Studio Beyond Limited | Professional & scientific | 2021 |
| Studio Bromo Limited | Information & communication | 2023 |
| Studio Flourish CIC | Education | 2025 |
| Studio Groundwork Ltd | Professional & scientific | 2024 |
| Studio Helen Ltd | Professional & scientific | 2012 |
| Studio Hobohm Limited | Professional & scientific | 2013 |
| Studio Iron Collective Ltd | Other services | 2026 |
| Studio O'Stray Ltd | Professional & scientific | 2025 |
| Studio One Design Limited | Professional & scientific | 2023 |
| Studio Pepwuper Limited | Information & communication | 2013 |
| Studio Susie Ltd | Information & communication | 2026 |
| Studio Timbren Limited | Professional & scientific | 2025 |
| Studio Violet Ltd | Education | 2026 |
| STUDIO17 Design Limited | Professional & scientific | 2010 |
| Studiokm Architects Limited | Professional & scientific | 2021 |
| Studlands Five Company Limited | Households | 1986 |
| Studlands SIX Company Limited | Households | 1986 |