| Smilemint Ltd | Health & social care | 2026 |
| Smiling Valley Ltd | Wholesale & retail | 2023 |
| Smirnaf Ltd | Wholesale & retail | 2025 |
| Smith Farm Autos Limited | Wholesale & retail | 2015 |
| SMK Advisory Ltd | Professional & scientific | 2026 |
| SN Khalsa Enterprise Limited | Professional & scientific | 2024 |
| Snak Shak Isleworth Ltd | Hospitality | 2026 |
| Snak Shak Ltd | Hospitality | 2024 |
| Snapboost Limited | Professional & scientific | 2017 |
| Snare Limited | Information & communication | 2026 |
| Snettisham Park Farm Barns Management Company Limited | Real estate | 2015 |
| Snow White Integrated Venture Limited | Other services | 2015 |
| SNP Technologies Limited | Information & communication | 2020 |
| SO Trade Ltd | Professional & scientific | 2018 |
| Sofa Summits Ltd | Administrative & support | 2020 |
| Sofialux Limited | Administrative & support | 2024 |
| Softbased Ltd | Information & communication | 2019 |
| Solar Properties (MCR) Ltd | Real estate | 2013 |
| Sole Savant Ltd | Administrative & support | 2024 |
| Solus Enterprise Limited | Wholesale & retail | 2017 |
| Solvra Services Ltd | Construction | 2025 |
| Solydcare Ltd | Administrative & support | 2022 |
| Sorority Movie Limited | Information & communication | 2019 |
| Sourze Ltd | Professional & scientific | 2012 |
| South Quay Deco Limited | Real estate | 2001 |
| South Street Cafe Limited | Hospitality | 2018 |
| South Street Group Limited | Hospitality | 2022 |
| South Street Ice Cream Limited | Manufacturing | 2014 |
| South Street in the Park Limited | Hospitality | 2016 |
| Southend Property Developments Ltd | Construction | 2017 |
| Souvenir Tours and Travel Ltd | Administrative & support | 2012 |
| Sovran Global Ltd | Construction | 2025 |
| SP Sound Limited | Information & communication | 2014 |
| Spacegirl Lunar Bikes Ltd | Wholesale & retail | 2024 |
| Spal Limited | Information & communication | 2023 |
| Sparking Space Ltd | Real estate | 2026 |
| Sparkline Ltd | Other services | 2022 |
| Sparkling Smiles Limited | Health & social care | 2015 |
| Sparks Chiswick Limited | Education | 2022 |
| Sparks Kingston & Richmond Limited | Education | 2022 |
| Sparks Teddington Limited | Education | 2026 |
| Sparks Wimbledon Limited | Education | 2022 |
| Sparkvolt Electrical Services Ltd | Construction | 2020 |
| Spatial Imaging Limited | Arts & recreation | 1994 |
| Speccon London Ltd | Construction | 2023 |
| Spectrum BMR Limited | Construction | 2018 |
| Spia-Mc Limited | Arts & recreation | 2017 |
| Spicy Loops Ltd | Hospitality | 2023 |
| Spirited Bar Ltd | Manufacturing | 2016 |
| Spmm Course Ltd | Education | 2008 |
| Sports Influence Ltd | Construction | 2016 |
| Spring Grove Consultancy Ltd | Professional & scientific | 2017 |
| Spring Grove Developments Limited | Real estate | 2025 |
| Spring Grove Properties Ltd | Real estate | 2020 |
| SPT Nutrition Limited | Health & social care | 2023 |
| SR Pilates Limited | Arts & recreation | 2025 |
| SRC Security Ltd | Administrative & support | 2023 |
| Sree Vasudha Ltd | Information & communication | 2013 |
| Srivastra Ltd | Information & communication | 2025 |
| SS Ebike Ltd | Wholesale & retail | 2024 |
| Sshc Limited | Administrative & support | 2016 |
| Ssjv Estates Ltd | Real estate | 2024 |
| Ssrm Properties Ltd | Real estate | 2024 |
| ST Christopher (Holdings) Limited | Real estate | 2020 |
| ST Lucas Ltd | Real estate | 2023 |
| ST Mary and ST Michael Property Ltd | Real estate | 2021 |
| ST Michael Oral Care Ltd | Health & social care | 2025 |
| ST Paul's Devonshire House Holdings Ltd | Real estate | 2020 |
| Stablegen Limited | Wholesale & retail | 2026 |
| Stabletech Limited | Wholesale & retail | 2026 |
| Stan Kolev Ltd | Construction | 2016 |
| Standalone Media Limited | Information & communication | 2013 |
| Star Contractors Limited | Construction | 1997 |
| Star Smart International Limited | Education | 2025 |
| Star Wrap Limited | Administrative & support | 2018 |
| Starbro Limited | Wholesale & retail | 2006 |
| Starc Services Limited | Wholesale & retail | 2020 |
| Starlife Company Services Limited | Administrative & support | 2008 |
| Starlight Trading London Ltd | Administrative & support | 2024 |
| Starline Painting Ltd | Construction | 2025 |
| Starlit Management Ltd | Real estate | 2023 |
| Stay Supa MC Ltd | Manufacturing | 2022 |
| Steadfast Care Service Ltd | Health & social care | 2023 |
| Stella Atkinson Limited | Administrative & support | 2015 |
| Sterling Global Traders Ltd | Wholesale & retail | 2025 |
| Stjnrd Apartment Limited | Real estate | 2024 |
| Stjnrd Flat Limited | Real estate | 2024 |
| Stonero Ltd | Households | 2025 |
| Stop Digging Warwickshire Limited | Construction | 2022 |
| Strategic PM Solutions Ltd | Real estate | 2017 |
| Stratfield Care LLP | | 2014 |
| Strawberry East Ltd | Wholesale & retail | 2026 |
| Strawberry Local Investment Ltd | Real estate | 2018 |
| Strax Limited | Information & communication | 2016 |
| Streamline Infotech UK Ltd | Information & communication | 2014 |
| Streamline Spaces UK Limited | Real estate | 2020 |
| Strop Limited | Arts & recreation | 2015 |
| Structural Design Consultants Ltd. | Professional & scientific | 2012 |
| Stryde Consulting Limited | Wholesale & retail | 2025 |
| Stuart's Cleaning Limited | Administrative & support | 2024 |