| Sommywhite Limited | Health & social care | 2014 |
| SON & Victor Ltd | Construction | 2022 |
| Sona Property Management Limited | Real estate | 2023 |
| Sonder Systems Ltd | Information & communication | 2024 |
| Sondo Limited | Health & social care | 2022 |
| Song Dynasty Music Group Ltd | Arts & recreation | 2020 |
| Sonic M&E Ltd | Construction | 2019 |
| Sonny White Group Limited | Construction | 2019 |
| Sonocareuk Ltd | Administrative & support | 2023 |
| Sons. Ltd | Hospitality | 2025 |
| Soomaney Software Ltd | Information & communication | 2022 |
| Soon Valley (UK) Limited | Wholesale & retail | 2021 |
| Sooncast Ltd | Construction | 2023 |
| Soov Ltd | Professional & scientific | 2013 |
| Sope Exotic Foods Ltd | Manufacturing | 2019 |
| Sophiben Healthcare Services Limited | Health & social care | 2014 |
| Sophie Fenton Limited | Information & communication | 2017 |
| Sophie's Super Shop Ltd | Wholesale & retail | 2024 |
| Soplar Care Limited | Health & social care | 2020 |
| Soratia Property Services Ltd | Real estate | 2024 |
| Sorelle Academy Limited | Arts & recreation | 2016 |
| Soroban Accountants Limited | Extraterritorial | 2020 |
| Sors Administrators Limited | Professional & scientific | 2022 |
| Soso Kebab Limited | Hospitality | 2025 |
| Sotia Consulting Ltd | Information & communication | 2024 |
| Souley Limited | Transport & logistics | 2023 |
| Soulful Minds Boutique Limited | Wholesale & retail | 2024 |
| Sound Frequencies Ltd | Arts & recreation | 2025 |
| Sound GAS Services Ltd | Construction | 2022 |
| Sound Guys Mischief Limited | Administrative & support | 1998 |
| Sourceandsave Ltd | Wholesale & retail | 2026 |
| Sourcedriven Limited | Information & communication | 2015 |
| Sourcewise Ltd | Information & communication | 2025 |
| Souroyer Limited | Administrative & support | 2016 |
| South Counties Property Management Ltd | Real estate | 2016 |
| South East Underpin Limited | Construction | 2004 |
| South Engineering Limited | Construction | 2017 |
| South Quay Asset Management Ltd | Real estate | 2019 |
| South Valley Properties Ltd | Real estate | 2020 |
| South Weald Swim School Ltd | Education | 2025 |
| Southend Timber Limited | Wholesale & retail | 2002 |
| Southern Drains & Water Ltd | Water & waste | 2018 |
| Southern Rail Utilities Ltd | Construction | 2023 |
| Southfield Realtors Ltd | Construction | 2017 |
| Southgate Construction Ltd | Construction | 2021 |
| Southpark Digital Signs Ltd | Professional & scientific | 2015 |
| Southtech Limited | Real estate | 1991 |
| Southwark After-School Club Ltd | Health & social care | 2025 |
| Southwest Fire and Security Limited | Public administration | 2009 |
| Southwold Crescent Limited | Energy | 2019 |
| Sovereign Holdings Limited | Real estate | 2026 |
| Soverign A.M Ltd | Financial services | 2025 |
| Sovrare Capital Ltd | Information & communication | 2026 |
| Sovrare Properties Ltd | Real estate | 2026 |
| Sovrin Properties Ltd | Real estate | 2026 |
| SP Building Construction Ltd | Construction | 2026 |
| SP Building Solutions Ltd | Construction | 2023 |
| SP Medical Limited | Health & social care | 2015 |
| SP Site Management Ltd | Construction | 2020 |
| Space Idea Ltd | Construction | 2017 |
| Space Times International Limited | Wholesale & retail | 2020 |
| Space Times Solutions Ltd | Information & communication | 2024 |
| Spacedwell Limited | Real estate | 2024 |
| Spaceship Investment Limited | Real estate | 2020 |
| Spaghetti Sound Limited | Information & communication | 2013 |
| Spahia Property Ltd | Real estate | 2026 |
| Spaiced Ltd | Real estate | 2026 |
| SPAJZ001 Ltd | Health & social care | 2016 |
| Sparc Consultants Limited | Information & communication | 2012 |
| Spark Materials Ltd | Construction | 2026 |
| Sparked OUT Ltd | Construction | 2020 |
| Sparktact Ltd | Professional & scientific | 2024 |
| Sparkvibeclean Limited | Administrative & support | 2025 |
| Spartan Strength and Conditioning Limited | Education | 2018 |
| Spartiate Ltd | Information & communication | 2020 |
| Spdrylining & Ceiling Ltd | Construction | 2016 |
| Speak for Less Ltd | Manufacturing | 2019 |
| Spearfox Ltd | Wholesale & retail | 2025 |
| Special Force Security Services Limited | Administrative & support | 2020 |
| Special Touch Audio Visual Limited | Professional & scientific | 2007 |
| Special Windows Ltd | Manufacturing | 2023 |
| Specialist Cleaners Ltd | Administrative & support | 2018 |
| Specific Environments (Construction) Limited | | 1979 |
| Spectacular Cleaning Services Limited | Administrative & support | 2025 |
| Speculaas Investments Ltd | Real estate | 2018 |
| Speed Courier Logistics Ltd | Construction | 2021 |
| Speed Drying Systems Ltd | Extraterritorial | 2007 |
| SPEED3NPL Ltd | Construction | 2024 |
| Speedoedu Consult International UK Ltd | Transport & logistics | 2026 |
| Speedy Cleaners Ltd | Administrative & support | 2025 |
| Spen Fitness Ltd | Arts & recreation | 2025 |
| Spencer Building Contractors Ltd | Construction | 2020 |
| Spenton Global Limited | Real estate | 2017 |
| Spice & Rice Ltd | Hospitality | 2024 |
| Spice Aiza Ltd | Hospitality | 2017 |
| Spice Clean Ltd | Households | 2023 |
| Spice IS Life Ltd | Manufacturing | 2020 |
| Spicy Dish Limited | Hospitality | 2021 |
| Spider Cranes Ltd | Administrative & support | 2025 |
| Spider Roofing Solutions Limited | Construction | 2025 |