| Sticky Digital Limited | Information & communication | 2008 |
| Stiles & Company Accountants Ltd | Extraterritorial | 2019 |
| Stiles & Company Financial Services Limited | Financial services | 2001 |
| Stiles Accountants Limited | Professional & scientific | 2015 |
| Stiles Advanced Financial Planning Limited | Professional & scientific | 2011 |
| Stip Holdings Ltd | Construction | 2026 |
| Stirling Moss Limited | Other services | 1954 |
| Stjn Property Ltd | Real estate | 2020 |
| STM Accountant Ltd | Professional & scientific | 2023 |
| Stockholm Ltd | Wholesale & retail | 2020 |
| Stockley Clinic Ltd | Health & social care | 2024 |
| Stoke Ripley Creative Limited | Administrative & support | 2009 |
| Stomperz Ltd | Manufacturing | 2021 |
| Stonebridge Design Limited | Professional & scientific | 2010 |
| Stonefield Property Maintenance Ltd | Other services | 2015 |
| Storia Creative Limited | Information & communication | 2012 |
| Storum Limited | Construction | 2016 |
| Story Bureau Limited | Professional & scientific | 2026 |
| Story for ALL Limited | Information & communication | 2025 |
| Storyden Limited | Arts & recreation | 2023 |
| Stoughton Limited | Wholesale & retail | 1997 |
| Stows Limited | Wholesale & retail | 2002 |
| STR Building Services Ltd | Construction | 2008 |
| Strande Lane Cookham Limited | Households | 2020 |
| Stranded Clothing Ltd | Wholesale & retail | 2025 |
| Strandfoam UK Limited | Manufacturing | 2021 |
| Stratagenie Ltd | Information & communication | 2025 |
| Strategem Solutions Limited | Education | 2012 |
| Strategic Accounting Partners Limited | Professional & scientific | 2023 |
| Strategic Growth Ventures Ltd | Professional & scientific | 2024 |
| Strategic Resource Solutions Limited | Professional & scientific | 2006 |
| Strategic Risks Limited | Information & communication | 1999 |
| Strategic Sales Consulting Limited | Professional & scientific | 2019 |
| Strategic Selection International Ltd | Administrative & support | 2018 |
| Strategic Selection Limited | Administrative & support | 1992 |
| Stratos Properties Ltd | Real estate | 2017 |
| Stratosphere Strategies Limited | Professional & scientific | 2026 |
| Strats AI Limited | Information & communication | 2025 |
| Stratton Valley Ltd | Hospitality | 2014 |
| Stratus Management Consulting Ltd | Administrative & support | 2014 |
| Strawberryfinch Limited | Professional & scientific | 2021 |
| Stray Bullet Ltd | Information & communication | 2012 |
| Streamlined Luxury Ltd | Other services | 2017 |
| Stretch Coaching Limited | Extraterritorial | 2013 |
| Stretch Learning Limited | Professional & scientific | 2005 |
| Stripes Bar Ltd | Hospitality | 2025 |
| Strongerfasterfitter Services Ltd | Education | 2021 |
| Stryica Limited | Arts & recreation | 2011 |
| Stuart Graham Consulting Ltd | Professional & scientific | 2020 |
| Stubbings Group Limited | Agriculture & fishing | 2003 |
| Stubbings Nursery Limited | Agriculture & fishing | 1999 |
| Studio 2 Maidenhead Ltd | Arts & recreation | 2026 |
| Studio Elstow Limited | Wholesale & retail | 2024 |
| Studio EP Limited | Professional & scientific | 2026 |
| Studio Mylon Ltd | Professional & scientific | 2026 |
| Studio Neier Limited | Manufacturing | 2026 |
| STUDIO@31 Limited | Arts & recreation | 2015 |
| Stump Pro Ltd | Construction | 2020 |
| Stunna Ltd | Wholesale & retail | 2021 |
| STX Property Management Limited | Real estate | 2017 |
| Style the People Limited | Wholesale & retail | 2023 |
| Stylus Capital Limited | Financial services | 2026 |
| Success Psychology Ltd | Administrative & support | 2021 |
| SUE Stephens Consultancy Ltd | Professional & scientific | 2010 |
| Suez Advanced Solutions Holding UK Limited | Financial services | 2010 |
| Suez Advanced Solutions UK Limited | Water & waste | 2006 |
| Suez Connect UK Ltd | Water & waste | 2019 |
| Suez Recycling and Recovery Holdings UK Ltd | Financial services | 1997 |
| Suez Recycling and Recovery Kirklees Ltd | Water & waste | 1998 |
| Suez Recycling and Recovery Lancashire Ltd | Water & waste | 1991 |
| Suez Recycling and Recovery North East Ltd | Water & waste | 1988 |
| Suez Recycling and Recovery Packington Ltd | Water & waste | 1979 |
| Suez Recycling and Recovery South East Ltd | Water & waste | 1934 |
| Suez Recycling and Recovery South Gloucestershire Ltd | Water & waste | 2000 |
| Suez Recycling and Recovery Southern Ltd | Water & waste | 1971 |
| Suez Recycling and Recovery Suffolk Ltd | Water & waste | 2010 |
| Suez Recycling and Recovery Surrey Ltd | Water & waste | 1996 |
| Suez Recycling and Recovery UK Group Holdings Ltd | Professional & scientific | 2006 |
| Suez Recycling and Recovery UK Ltd | Water & waste | 1988 |
| Suez Recycling and Recovery UK Pensions Plans Trustees Ltd | Professional & scientific | 1996 |
| Suez UK Environment Ltd | Water & waste | 1978 |
| Suffolk Street Holdings Limited | Financial services | 2021 |
| Sufyan Wholesalers Ltd | Wholesale & retail | 2025 |
| Suite Hub Limited | Other services | 2007 |
| Suite Spots KR Ltd | Real estate | 2025 |
| Sulit Sales Ltd | Information & communication | 2019 |
| SUM Plus Ltd | Professional & scientific | 2015 |
| Sumit Transport Ltd | Transport & logistics | 2025 |
| Summercombe NO 87 Limited | Wholesale & retail | 1999 |
| Summerleaze Lake Residents Ltd | Households | 2022 |
| Summerleaze Sport C.I.C. | Arts & recreation | 2017 |
| Summit Platforms Ltd | Administrative & support | 2014 |
| Summit Power Generation Ltd | Administrative & support | 2023 |
| Summit Rentals Group Ltd | Extraterritorial | 2023 |
| Sunadokei LA Mehdood Ltd | Information & communication | 2025 |
| Sunbakes Ltd | Manufacturing | 2018 |
| Sundiv Process Consultants Limited | Information & communication | 2008 |
| Sundown Group Limited | Financial services | 2021 |
| Sundown IP Limited | Extraterritorial | 2021 |
| Sundown Solutions Limited | Information & communication | 2009 |