| Sopranai Limited | Other services | 2017 |
| Sort IT Construction Limited | Construction | 2026 |
| Soul & Mind Development Group Ltd | Construction | 2024 |
| Soundtech (Europe) Limited | Professional & scientific | 2014 |
| Sourabh Engineering Limited | Transport & logistics | 2011 |
| Sourcify Global Limited | Wholesale & retail | 2023 |
| Sousa Builders and Decorators Ltd | Construction | 2024 |
| South Coast Contract Services Ltd | Professional & scientific | 2026 |
| South Drive Investments Limited | Households | 2024 |
| South Harrow Property Ltd | Real estate | 2021 |
| South Lodge Properties Ltd | Real estate | 2018 |
| South West Quarter Ltd | Real estate | 2020 |
| Southall Athletic FC CIC | Education | 2026 |
| Southall Athletic Group Ltd | Professional & scientific | 2026 |
| Southall Athletic WFC CIC | Arts & recreation | 2025 |
| Southall Street Food Luton Ltd | Hospitality | 2024 |
| Southall Windows Ltd | Construction | 2017 |
| Southampton Convenience Store Ltd | Wholesale & retail | 2026 |
| Southway Investments Ltd | Real estate | 2015 |
| Southwest Apartments Ltd | Construction | 2025 |
| Sovanni Limited | Health & social care | 2023 |
| Sovereign & Fair Accounting Solutions Ltd | Professional & scientific | 2025 |
| Sovereign Transport Ltd | Transport & logistics | 2020 |
| Sovereigngo Ltd | Transport & logistics | 2026 |
| SP Studio Unisex Ltd | Other services | 2020 |
| Spa House (Hayes) RTM Company Limited | Households | 2025 |
| Spa Porter Ltd | Other services | 2018 |
| Space Contractors Limited | Construction | 2008 |
| Spacetel Managed Services Limited | Financial services | 2009 |
| Spacetel UK Limited | Information & communication | 1995 |
| Spandana Enterprises Ltd | Wholesale & retail | 2015 |
| Spank Media Limited | Extraterritorial | 2008 |
| Spark & Soul Ltd | Wholesale & retail | 2025 |
| Sparkle Jewellery Ltd | Wholesale & retail | 2024 |
| Sparklink Finance Ltd | Financial services | 2025 |
| Sparktricity (UK) Ltd | Construction | 2012 |
| Sparktricity Limited | Construction | 2006 |
| Sparky Brothers Limited | Construction | 2025 |
| Spartans Constructions Limited | Construction | 2025 |
| Special Task Force Ltd | Administrative & support | 2017 |
| Speciality Bathroom Concepts Limited | Wholesale & retail | 2023 |
| Specterslitt Bedrooms and Kitchens Limited | Construction | 2025 |
| Speed Meet and Greet Ltd | Hospitality | 2026 |
| Speedway Cargo & Freight (UK) Ltd | Transport & logistics | 2018 |
| Speedway Haulage & Storage Limited | Transport & logistics | 1990 |
| Speedy 247 Limited | Financial services | 2020 |
| Speedy Haulage Ltd | Transport & logistics | 2021 |
| Spence Transport Limited | Transport & logistics | 1970 |
| Spice Ceylon UK Limited | Wholesale & retail | 2024 |
| Spice of East Ltd | Hospitality | 2020 |
| Spice Spoon Ltd | Hospitality | 2018 |
| Spicy Singh Ltd | Wholesale & retail | 2025 |
| Spideralpine Ltd | Manufacturing | 2026 |
| SPJ Estate Investments Limited | Real estate | 2025 |
| SPJ Investments Limited | Real estate | 2013 |
| Splendix Ltd | Wholesale & retail | 2016 |
| SPM Investment Ltd | Real estate | 2018 |
| SPM Studios Ltd | Manufacturing | 2025 |
| Sponsor License Ltd | Information & communication | 2026 |
| Sponsorhr Ltd | Information & communication | 2024 |
| Sporttiers FC Limited | Education | 2022 |
| Sporttiers Limited | Education | 2021 |
| Spotclean Solutions Limited | Administrative & support | 2008 |
| Spotless Kleen Limited | Administrative & support | 2019 |
| Spring Building Services Ltd | Construction | 2026 |
| Spring Raise Ltd | Administrative & support | 2015 |
| SPS Sales Limited | Wholesale & retail | 2016 |
| Spsourcing Ltd | Administrative & support | 2025 |
| Sptee Ltd | Wholesale & retail | 2023 |
| SPV Construction Limited | Real estate | 2025 |
| SPV Services Limited | Wholesale & retail | 2017 |
| SPY Target Ltd | Public administration | 2023 |
| Squad-V Sports CIC | Arts & recreation | 2025 |
| Square Centimeter Ltd | Construction | 2023 |
| SR Great Limited | Construction | 2025 |
| Sran Middlesex Maintenance Ltd | Construction | 2023 |
| Srbv Services Ltd | Administrative & support | 2022 |
| Sree Dhanya Ltd | Information & communication | 2010 |
| SRG Pro Ltd | Real estate | 2020 |
| SRI RAM Properties UK Investments Ltd | Real estate | 2021 |
| Srilatha Enterprises Ltd | Construction | 2022 |
| Sriwin Esan Limited | Health & social care | 2023 |
| SRN Traders Limited | Wholesale & retail | 2024 |
| SRP Hotel Booking Ltd | Transport & logistics | 2022 |
| SRS Enterprises Ltd | Wholesale & retail | 2022 |
| Srtd Limited | Real estate | 2026 |
| SRV Property Limited | Real estate | 2021 |
| SS Accountancy Services Limited | Professional & scientific | 2022 |
| SS Arora Ltd | Construction | 2021 |
| SS Ecomm Ltd | Wholesale & retail | 2024 |
| SS Fitted Interiors Ltd | Construction | 2026 |
| SS Fone Accessories Limited | Wholesale & retail | 2019 |
| SS Food & Wine Ltd | Wholesale & retail | 2017 |
| SS HGV Driving Limited | Transport & logistics | 2008 |
| SS Midland Ltd | Wholesale & retail | 2018 |
| SS Momi Construction Ltd | Construction | 2019 |
| SS Nirvana Ltd | Other services | 2026 |
| SS Peri Peri Fries Ltd | Hospitality | 2026 |
| SS Sidhu Builders Ltd | Construction | 2024 |
| SS Signatures Limited | Real estate | 2023 |