| Sonocast Ltd | Health & social care | 2022 |
| Sonorous Limited | Administrative & support | 2001 |
| Sood ENT Ltd | Health & social care | 2023 |
| Sooho Properties Ltd | Real estate | 2024 |
| Sophia Property Investments Limited | Construction | 2025 |
| SOPHOS6 Limited | Professional & scientific | 2025 |
| Sopit Construction Ltd | Construction | 2026 |
| Soprano Events Ltd | Information & communication | 2018 |
| SOR ARP Ltd | Professional & scientific | 2026 |
| Sora and Sea Ltd | Wholesale & retail | 2025 |
| Sora Heritage Ltd | Real estate | 2026 |
| Sorarise Limited | Professional & scientific | 2026 |
| Soraya Sandra Makorie & Co Ltd | Professional & scientific | 2023 |
| Sordillo Ltd | Real estate | 2024 |
| Sorella Investments Ltd | Financial services | 2025 |
| Sorgex Ltd | Information & communication | 2019 |
| Sorrell & Co Property Ltd | Real estate | 2026 |
| Sorriso Design Limited | Health & social care | 2020 |
| Sorte Ltd | Wholesale & retail | 2024 |
| SOS Coatings Ltd | Construction | 2020 |
| SOS Digital Limited | Extraterritorial | 2016 |
| SOS MK Ltd | Construction | 2019 |
| Sosa Atelier Limited | Wholesale & retail | 2022 |
| Sosume Limited | Professional & scientific | 2016 |
| Sotiavio Solutions Limited | Manufacturing | 2022 |
| Soul Beauty & Training Academy Ltd | Education | 2024 |
| Soul Flavrs Ltd | Hospitality | 2025 |
| Soul Shack Ltd | Hospitality | 2026 |
| Soul Studio Limelight Limited | Hospitality | 2026 |
| Soulimage Promotions Ltd | Wholesale & retail | 2017 |
| Sound Conduct Ltd | Information & communication | 2020 |
| Sound Life Ltd | Financial services | 2018 |
| Sound Output Limited | Information & communication | 2023 |
| Sound Professional Systems Ltd | Wholesale & retail | 2018 |
| Sound Scaffolding Services Ltd | Construction | 2018 |
| Sound Solution Consultants Limited | Construction | 2005 |
| Sounded Trading Limited | Wholesale & retail | 2024 |
| Soundsteps Music School Limited | Education | 2001 |
| Source 18 Ltd | Information & communication | 2018 |
| Source Complex Home Care Ltd | Health & social care | 2017 |
| Source Graphics Limited | Manufacturing | 2007 |
| Source Leisure Limited | Wholesale & retail | 2024 |
| Source Properties Limited | Real estate | 2021 |
| Sourced by Sonia Ltd | Real estate | 2025 |
| Sourced Development Group Ltd | Construction | 2019 |
| Sourcing Maze Ltd | Wholesale & retail | 2019 |
| Sousourada (UK) Limited | Wholesale & retail | 2023 |
| Sousourada Limited | Wholesale & retail | 2019 |
| Souster and Hicks (Savile ROW) Ltd | Wholesale & retail | 2003 |
| South Bedfordshire Investments Limited | Real estate | 2009 |
| South Brit Maintenance Ltd | Construction | 2025 |
| South Molton Transport Limited | Transport & logistics | 1999 |
| South ROW South Fifth Street MK Freehold Limited | Households | 2021 |
| South Vernon Associates Limited | Professional & scientific | 2015 |
| South West Brands Limited | Financial services | 2021 |
| Southend Dog Training Ltd | Education | 2020 |
| Southern Cape Bottling International Ltd | Wholesale & retail | 2023 |
| Southern Choice Ltd | Wholesale & retail | 2025 |
| Southern Landscapes & Construction Ltd | Construction | 2003 |
| Southern Monitoring Services Limited | Administrative & support | 1983 |
| Southern Render Supplies Limited | Construction | 2020 |
| Southern Tribes United Kingdom Community Interest Company | Arts & recreation | 2026 |
| Southernmart-Mk Limited | Wholesale & retail | 2022 |
| Southview Online Farm Shop Ltd | Wholesale & retail | 2024 |
| Southwark Bridge Holdings Limited | Professional & scientific | 2015 |
| Southway Scania Limited | Wholesale & retail | 1989 |
| Southwest Seating & Rehab Limited | Manufacturing | 1993 |
| Sovendus UK Limited | Administrative & support | 2011 |
| Sovereign Collectable Ltd | Wholesale & retail | 2026 |
| Sovereign Commercial Investments Ltd | Real estate | 2024 |
| Sowax LEE Group Ltd | Mining & quarrying | 2015 |
| Sower Health Care Ltd | Health & social care | 2021 |
| Soyking Limited | Agriculture & fishing | 2014 |
| Soyo Ltd | Health & social care | 2022 |
| SP Consult Ltd | Professional & scientific | 2008 |
| SP Engineering Ltd | Manufacturing | 2026 |
| SP Frampton Facade Limited | Construction | 2018 |
| SP Warehousing Ltd | Transport & logistics | 2026 |
| SP Xpress Ltd | Transport & logistics | 2015 |
| Spa Clean Laundry Limited | Other services | 2025 |
| Spa Investment 2020 Limited | Financial services | 2020 |
| Space Efficient Interiors Limited | Construction | 1999 |
| Space Factor Ltd | Real estate | 2022 |
| Space Freight Ltd | Wholesale & retail | 2024 |
| Space Internet Installations Ltd | Information & communication | 2021 |
| Space Kraft (UK) Limited | Construction | 2014 |
| Space ONESIX3 Ltd | Arts & recreation | 2026 |
| Space Science Solutions Ltd | Professional & scientific | 2015 |
| Spacecircuits Ltd | Information & communication | 2007 |
| Spacecraft IND Ltd | Professional & scientific | 2019 |
| Spaceinvapers Limited | Wholesale & retail | 2017 |
| Spado Media Ltd | Professional & scientific | 2019 |
| Spage Offshore Limited | Financial services | 2026 |
| Spanglish Properties Ltd | Real estate | 2018 |
| Spanners & Heels Ltd | Wholesale & retail | 2014 |
| Spare Parts Assistant Ltd | Wholesale & retail | 2019 |
| Spark Hub CIC | Education | 2017 |
| Spark Link Engineering Ltd | Professional & scientific | 2023 |
| Sparkbridge Digital Ltd | Information & communication | 2025 |
| Sparkl Spaces Limited | Administrative & support | 2017 |