| Smith Family Property Investments Ltd | Real estate | 2021 |
| Smith MAY Solicitors LLP | | 2008 |
| Smith Roofing Ltd | Construction | 2026 |
| Smiths Children Ltd | Education | 2026 |
| Smiths Orchard Management Limited | Real estate | 2021 |
| Smiths Retail Ltd | Wholesale & retail | 2013 |
| Smithsonia Consultants Ltd | Professional & scientific | 2019 |
| SMJ Engineering Limited | Manufacturing | 2022 |
| SMO Technologies Ltd | Information & communication | 2017 |
| Smokehouse Yard Limited | Real estate | 2008 |
| Smokeworks Limited | Hospitality | 2014 |
| Smokey Mews Carriages Management Company Limited | Households | 2012 |
| Smokey Mews Management Company Limited | Households | 2012 |
| Smooth Hound Innovations Limited | Professional & scientific | 2013 |
| SMS RAD Limited | Health & social care | 2022 |
| SMT Group Limited | Hospitality | 2023 |
| Smtravel Limited | Administrative & support | 2021 |
| Smudgefam Limited | Manufacturing | 2015 |
| Smwmentenanta Ltd | Manufacturing | 2025 |
| Smwmt Ltd | Manufacturing | 2026 |
| Smyrna Trade Ltd | Wholesale & retail | 2020 |
| Snagclad Ltd | Construction | 2021 |
| Snap Find Ltd | Information & communication | 2022 |
| Snap! 4 Kids Limited | Education | 2003 |
| Snell David Cambridge Holdings Limited | Financial services | 2026 |
| Snell David Cambridge Ltd | Professional & scientific | 2017 |
| SNI Medicolegal Ltd | Health & social care | 2026 |
| Snicket Media Ltd | Arts & recreation | 2023 |
| Snorri's Realm Ltd | Arts & recreation | 2017 |
| Snowdrop Analytics Ltd | Education | 2021 |
| Snowdrop Estates Ltd | Real estate | 2019 |
| SO Blooming Beautiful Ltd | Wholesale & retail | 2018 |
| SO SAY WE ALL Media Ltd | Information & communication | 2019 |
| Soaring Kite Psychology Ltd | Health & social care | 2025 |
| Sober Safe UK Ltd | Information & communication | 2020 |
| Sobisz Ltd | Extraterritorial | 2014 |
| SOC & Growth Ltd | Information & communication | 2025 |
| Socan Enterprises Group Co., Ltd | Wholesale & retail | 2011 |
| Social Enterprise East of England (S.E.E.E.) Limited | Administrative & support | 2005 |
| Social Housing Estates Limited | Real estate | 2022 |
| Social Shaping Research Ltd | Information & communication | 2015 |
| Society for Research on Nicotine and Tobacco - Europe | Professional & scientific | 2011 |
| Sociofy Limited | Extraterritorial | 2019 |
| Socrates Software Limited | Information & communication | 2011 |
| Sodux Ltd | Construction | 2026 |
| Sofcomit Limited | Information & communication | 1999 |
| Sofiastrat Limited | Professional & scientific | 2024 |
| Sofronov Composites Ltd | Manufacturing | 2024 |
| Soft Music Ltd | Wholesale & retail | 2016 |
| Soft Tech Global Ltd | Information & communication | 2025 |
| Softica Ltd. | Manufacturing | 2007 |
| Software Acumen Limited | Information & communication | 2004 |
| Software Delivery Solutions Limited | Information & communication | 2013 |
| Software Development Design & Consultancy Limited | Information & communication | 1997 |
| Sogive Ltd | Extraterritorial | 2016 |
| Sogo Assessments Ltd | Professional & scientific | 2025 |
| Sohaai Ltd | Information & communication | 2025 |
| Sohoedge Limited | Wholesale & retail | 2025 |
| Sohow Shipping Marine Service Co., Limited | Wholesale & retail | 2025 |
| Soilbeing Ltd | Information & communication | 2012 |
| Soio Composites Ltd | Manufacturing | 2022 |
| Soko Beauty Limited | Professional & scientific | 2016 |
| SOL Creative Foundry Ltd | Arts & recreation | 2025 |
| SOL Haven Limited | Construction | 2025 |
| SOL Infotech Ltd | Information & communication | 2004 |
| Solara KL Ltd | Wholesale & retail | 2025 |
| Solarfarm Solutions Limited | Construction | 2016 |
| Solaris Photonics Ltd | Professional & scientific | 2009 |
| Solascure Limited | Professional & scientific | 2017 |
| Solcamb Limited | Information & communication | 2013 |
| Soldt Chemical Industry Co., Ltd | Manufacturing | 2023 |
| Sole and Shine Ltd | Wholesale & retail | 2025 |
| Solemn Investments Limited | Financial services | 2019 |
| Solemnity Consulting Limited | Information & communication | 2016 |
| Soletu Security Ltd | Administrative & support | 2025 |
| Solidcare Infratech Ltd | Construction | 2023 |
| Solidx Limited | Information & communication | 2023 |
| Soligenix UK Limited | Professional & scientific | 2008 |
| Solin Kebab Ltd | Hospitality | 2026 |
| Solis Horizon Ltd | Wholesale & retail | 2025 |
| Solitech Sound Lighting & AV Services Ltd | Professional & scientific | 2017 |
| Solly Little Limited | Wholesale & retail | 2024 |
| Sollyn Arzen Co., Limited | Manufacturing | 2025 |
| Solomon Property Limited | Real estate | 2021 |
| Solonworks Ltd | Information & communication | 2026 |
| Solopark Limited | Wholesale & retail | 1976 |
| Solos Hair and Beauty Ltd | Other services | 2011 |
| Solstus Ltd | Wholesale & retail | 2023 |
| Soluton Ltd | Information & communication | 2019 |
| Solvable.Health Ltd | Information & communication | 2026 |
| Solvicode Ltd | Information & communication | 2023 |
| Solvionix Co., Limited | Manufacturing | 2025 |
| Somerhill Leisure Limited | Households | 1998 |
| Somersault Ltd | Information & communication | 2020 |
| Somerset House Management Company Limited | Households | 1986 |
| Somersham Residents Association Limited | Households | 1991 |
| Somersham Scaffolding Limited | Construction | 2021 |
| Something About EAT Ltd | Hospitality | 2015 |
| Something to Look Forward to Limited | Health & social care | 2015 |
| Somnyx Ltd | Information & communication | 2025 |