| STK Mray Group Limited | Extraterritorial | 2011 |
| STM Collection Limited | Real estate | 2026 |
| Stock Electrics Limited | Construction | 2015 |
| Stone Applications UK Ltd | Construction | 2012 |
| Stone Code Ltd | Information & communication | 2019 |
| Stone-Fish London Limited | Professional & scientific | 2012 |
| Stonehenge Cafe Ltd | Hospitality | 2025 |
| Stonehill Court (Chingford) RTM Company Limited | Households | 2013 |
| Stonewalk Allure Limited | Other services | 2019 |
| Stoneygate Limited | Other services | 2010 |
| Storyarc Limited | Professional & scientific | 2025 |
| Storyzoo Ltd | Information & communication | 2025 |
| Stotfold (Property) Limited | Households | 1962 |
| STR8FORWARD Group Ltd | Construction | 2026 |
| Strand House RTM Company Ltd | Households | 2021 |
| Strangely Interactive Limited | Information & communication | 2014 |
| Strata Works Limited | Construction | 2026 |
| Stratahouse Limited | Professional & scientific | 1996 |
| Strategic Asset Management Consulting Limited | Professional & scientific | 2016 |
| Strategic Insight Consulting Limited | Professional & scientific | 2020 |
| Strategic Property Consultants Ltd | Professional & scientific | 2025 |
| Strategic Site Solutions Limited | Construction | 2021 |
| Stratford Place (Bickley) Management Limited | Households | 1994 |
| Stratheden Court RTM Company Limited | Households | 2008 |
| Stratosure Solutions Limited | Professional & scientific | 2025 |
| Stratrai Ltd | Other services | 2016 |
| Stratton Court (Beckenham) Residents Association Limited | Households | 1993 |
| Stratton Court Management (Croydon) Limited | Real estate | 1988 |
| Streamlined Accounting & Bookkeeping Solutions Ltd | Professional & scientific | 2023 |
| Street Performers Association | Other services | 2011 |
| Streppy Estates Ltd | Real estate | 2020 |
| Streppy Ltd | Manufacturing | 2011 |
| Stressless UK Ltd | Information & communication | 2025 |
| Stride Housing Solutions Ltd | Real estate | 2022 |
| Striker Productions Ltd | Other services | 2011 |
| Stringer Broking Limited | Financial services | 2019 |
| Strng & Fit Limited | Arts & recreation | 2022 |
| Strokesaver (UK) Holdings Limited | Professional & scientific | 2006 |
| Strongarm Chase Limited | Real estate | 2016 |
| Stroud Community Land Trust | Administrative & support | 2000 |
| Structo Solutions Ltd | Construction | 2025 |
| Strutt Fireproofing Limited | Information & communication | 2025 |
| Struxton & Co Limited | Construction | 2025 |
| Sttmonster International Ltd | Extraterritorial | 2024 |
| Stuart Bradley Solutions Limited | Construction | 2013 |
| Stuart Ensor Limited | Information & communication | 2026 |
| Stuart Manktelow Limited | Manufacturing | 2020 |
| Student Homes and Houses Limited | Households | 2021 |
| Studio 2.0 Limited | Other services | 2019 |
| Studio 42 Tattoos Limited | Arts & recreation | 2025 |
| Studio 74 Management Limited | Arts & recreation | 2015 |
| Studio 74 Showtime Productions Limited | Arts & recreation | 2024 |
| Studio Clarence and Graves Limited | Professional & scientific | 2006 |
| Studio EC Interiors Limited | Professional & scientific | 2024 |
| Studio EC Limited | Professional & scientific | 2021 |
| Studio G and C Ltd | Wholesale & retail | 2025 |
| Studio LA Limited | Professional & scientific | 2005 |
| Studio Land Art Limited | Professional & scientific | 2010 |
| Studio LS Media Limited | Professional & scientific | 2026 |
| Studio Mehm Ltd | Professional & scientific | 2024 |
| Studio Peacock Limited | Professional & scientific | 2024 |
| Studio Sixty Two Ltd | Arts & recreation | 2021 |
| Studio Xenon Ltd | Information & communication | 2013 |
| Study Consulting Ltd | Education | 2021 |
| Stunning Flooring Centre Ltd | Construction | 2017 |
| Sturdy Europe Limited | Wholesale & retail | 2015 |
| Stwc Investments Ltd | Real estate | 2022 |
| Styled by Arii Ltd | Other services | 2026 |
| Styleframe Design Limited | Professional & scientific | 2014 |
| Stäbz Ltd | Wholesale & retail | 2016 |
| Subfrantic Ltd | Information & communication | 2014 |
| Sublime Land (Brickendon) Ltd | Real estate | 2009 |
| Sublime Land Limited | Construction | 2009 |
| Subutai Limited | Construction | 2024 |
| SUCCESS4PARTNERS Ltd | Information & communication | 2019 |
| Sucker for Sweets Ltd | Other services | 2018 |
| Sucrerie Consultancy Ltd | Hospitality | 2025 |
| SUE Mccready Consulting Ltd | Wholesale & retail | 2020 |
| Sueshi Limited | Administrative & support | 2020 |
| Sugar Associates Limited | Professional & scientific | 2010 |
| Sugarplumbows Limited | Wholesale & retail | 2017 |
| Sugarplumz Ltd | Education | 2011 |
| Suitcase Blues Ltd | Arts & recreation | 2018 |
| Suite One Limited | Information & communication | 2022 |
| Sukunai Data Ltd | Information & communication | 2023 |
| Sullivan Trading Associates Ltd | Real estate | 2019 |
| Sultans Manor Limited | Wholesale & retail | 2021 |
| Summerhill Residents Association Limited | Households | 1988 |
| Summerhill Way Freehold Company Limited | Real estate | 2016 |
| Sumo Creative Ltd | Administrative & support | 2009 |
| Sunbeam 13 Limited | Wholesale & retail | 2021 |
| Sunbeam Marketing Ltd | Professional & scientific | 2024 |
| Sunbear Capital Ltd | Administrative & support | 2020 |
| Sundridge Building Supplies Limited | Wholesale & retail | 2024 |
| Sundridge Cafe Limited | Hospitality | 2013 |
| Sundridge Coffee Limited | Hospitality | 2017 |
| Sundridge Heights Management Company Limited | Real estate | 2004 |
| Sundridge Homes & Gardens Limited | Construction | 2024 |
| Sundridge Interiors Limited | Wholesale & retail | 2018 |
| Sundridge Park Racquets Limited | Arts & recreation | 2026 |