| Solid Maths Limited | Education | 2025 |
| Sommeliers Choice Limited | Wholesale & retail | 1999 |
| Sonamoor Property Management Limited | Professional & scientific | 1998 |
| Sonia Beauty (UK) Ltd | Other services | 2013 |
| Sonic Hearing Limited | Health & social care | 2010 |
| Sono Fabrics Limited | Wholesale & retail | 2022 |
| Sorek Services Limited | Professional & scientific | 2003 |
| South Anston Limited | Construction | 2005 |
| Southbeach Solutions Ltd | Information & communication | 2009 |
| Southern Counties Fire Limited | Construction | 2025 |
| Southern EET Testing Ltd | Professional & scientific | 2022 |
| Southwood Landlord Services Limited | Other services | 2019 |
| Spare Capacity Global Limited | Information & communication | 2025 |
| Spark Consultancy Services Limited | Information & communication | 2015 |
| Sparkle and Shield Cleaning Company Limited | Administrative & support | 2025 |
| Specs Tech UK Ltd | Wholesale & retail | 2020 |
| Speedwell Assets Ltd | Real estate | 2022 |
| Speranza Resources Ltd | Wholesale & retail | 2020 |
| Spice Magic Limited | Professional & scientific | 2000 |
| Sports Active Coaching (Schools) Limited | Education | 2019 |
| Sports Entertainment International Management LLP | | 2012 |
| Spotty P Ltd | Wholesale & retail | 2020 |
| Springco Ltd | Real estate | 2018 |
| Square Tail Design Ltd | Construction | 2019 |
| Sreenesh Property Ltd | Real estate | 2025 |
| SRI DMR Technology Consulting Limited | Information & communication | 2012 |
| Sris Group Limited | Wholesale & retail | 2017 |
| Sris Innovation Limited | Wholesale & retail | 2017 |
| Sris Tech Limited | Wholesale & retail | 2017 |
| SRJ Consulting Limited | Information & communication | 2012 |
| SS Empire Limited | Real estate | 2020 |
| SS24 Ltd | Health & social care | 2023 |
| Ssdn Smile Limited | Administrative & support | 2011 |
| SSS Traders Ltd | Transport & logistics | 2018 |
| ST Denys Close (Purley) Residents Management Company Limited | Administrative & support | 2010 |
| Stanley Management Group Limited | Real estate | 2019 |
| Starmaker Property Limited | Real estate | 2024 |
| Station Point Purley Limited | Construction | 2021 |
| Stefano Serpillo Signature Homes Limited | Real estate | 2026 |
| Stellenbosch Investments Ltd | Real estate | 2019 |
| Stellenbosch Two Limited | Real estate | 2021 |
| Stenning Engineering Ltd | Manufacturing | 2014 |
| Sterling Commercial Management Ltd | Households | 2024 |
| Sterling Development and Construction Limited | Construction | 2025 |
| Sterling Properties (Europe) Limited | Real estate | 2024 |
| Sterlings and ROW Limited | Manufacturing | 2026 |
| Steve Douglas Contractor Ltd | Construction | 2017 |
| Steven Robertson Art Ltd | Wholesale & retail | 2024 |
| Stockwood Advisory Services Ltd | Financial services | 2017 |
| Stoneyford One Properties Ltd | Real estate | 2021 |
| Store-Pit UK Limited | Transport & logistics | 2025 |
| Stovka Ltd | Professional & scientific | 2025 |
| Stratanix AI Ltd | Information & communication | 2026 |
| Stratovate Consulting Limited | Information & communication | 2025 |
| Strong Style Empire Limited | Arts & recreation | 2020 |
| Strongheart Surveying Ltd | Professional & scientific | 2026 |
| Studio Ninety Eight Ltd | Arts & recreation | 2025 |
| Studio Twenty Three Limited | Real estate | 2016 |
| Sugar Consult Ltd | Financial services | 2025 |
| Sullivan Court Property Company Limited | Households | 1986 |
| SUM Investments Limited | Professional & scientific | 2004 |
| Sun Estates 2021 Limited | Real estate | 2021 |
| Sunduo Ltd | Information & communication | 2022 |
| Sunhill Reinvent Ltd | Real estate | 2026 |
| Sunningvale Service Station BH Limited | Wholesale & retail | 1971 |
| Sunrise House Freehold Company Limited | Households | 2020 |
| Sunrise Kingston Development Ltd | Construction | 2026 |
| Super Image (UK) Limited | Manufacturing | 2013 |
| Super IT Tech Ltd | Manufacturing | 2024 |
| Supreme ACT Consulting Limited | Professional & scientific | 2022 |
| Sure Planning Ltd | Information & communication | 2021 |
| Surelex Limited | Other services | 1998 |
| Surrey Phoenix Ltd | Hospitality | 2020 |
| Surrey Spine Clinic Limited | Health & social care | 2017 |
| Sustento Services Limited | Construction | 2024 |
| Sutco UK Limited | Manufacturing | 2002 |
| Sutton & Croydon Utsav Committee Ltd | Other services | 2023 |
| SV Detaling Ltd | Administrative & support | 2024 |
| SV Prime Investments Ltd | Real estate | 2024 |
| Swati Varanasi Holdings Limited | Financial services | 2026 |
| Swift Food London Ltd | Hospitality | 2019 |
| Swim to WIN (CHS) Ltd | Education | 2017 |
| Swimfix Academy Limited | Arts & recreation | 2012 |
| Syknd Investments Limited | Real estate | 2024 |
| Synergy Book Sales UK Limited | Wholesale & retail | 2021 |
| Synergy Tax Limited | Administrative & support | 2017 |
| T a Mechanical Solutions Ltd | Construction | 2024 |
| T G P Maintenance S Ltd | Construction | 2013 |
| T J Dunnett Engineering Ltd. | Professional & scientific | 2019 |
| T J Footwear (UK) Limited | Administrative & support | 1995 |
| Table Maker Catering Limited | Hospitality | 2024 |
| Tactical Project Management Ltd | Administrative & support | 2026 |
| Taheel Integrated Services Limited | Hospitality | 2023 |
| Tameer Estates Ltd | Construction | 2023 |
| Tanveer Cakes and Savouries Limited | Wholesale & retail | 2026 |
| Taurus Monitored Services Limited | Administrative & support | 2017 |
| Taya Purley Oriental Ltd | Hospitality | 2026 |
| Taygo Macondo Investments Ltd | Real estate | 2017 |
| TDA Medical Services Ltd | Health & social care | 2016 |
| TEC Holdings Limited | Other services | 2017 |