| Seoul Savory Ltd | Hospitality | 2025 |
| Septacular Homes Ltd | Financial services | 2024 |
| Sequoia London Limited | Construction | 2014 |
| Serans Limited | Wholesale & retail | 2009 |
| Serelix AI Ltd | Information & communication | 2025 |
| Serendipp Limited | Hospitality | 2025 |
| Serenite Massage Ltd | Health & social care | 2011 |
| Serenity Beauty Saloon Ltd | Other services | 2023 |
| Serenity Dreamscape Ltd | Wholesale & retail | 2023 |
| Serenity Living | Health & social care | 2018 |
| Serenity School Old Palace Croydon Ltd | Education | 2025 |
| Serenova Group Holdco Ltd | Education | 2026 |
| Seriously Ltd | Real estate | 2023 |
| Seritho Ltd | Wholesale & retail | 2025 |
| Servercore Solutions Ltd | Wholesale & retail | 2025 |
| Service Technology Ltd | Information & communication | 2021 |
| Services Direct (London) Ltd | Administrative & support | 2016 |
| Servicestart Limited | Information & communication | 2006 |
| Servie Oskar Ltd | Wholesale & retail | 2025 |
| SET Point Group Limited | Real estate | 2019 |
| SET Tuition Centre Limited | Education | 2025 |
| SET Tuition Limited | Education | 2022 |
| Setso UK Ltd | Wholesale & retail | 2022 |
| Setu Capital Limited | Real estate | 2025 |
| Setworks Limited | Arts & recreation | 2013 |
| Seven Automotive Limited | Wholesale & retail | 2020 |
| Seven H Limited | Information & communication | 2014 |
| Seven N Half Limited | Wholesale & retail | 2016 |
| Seven Parade Ltd | Real estate | 2025 |
| Seven St.Gregory's Road Limited | Households | 2004 |
| Seven Stories London Limited | Wholesale & retail | 2017 |
| Seven Twelve Ventures Ltd | Wholesale & retail | 2022 |
| Seven Westgate Terrace Management Limited | Households | 1994 |
| Sevenoaks Property Maintenance Limited | Construction | 2014 |
| Seventeen Communication Ltd | Professional & scientific | 2014 |
| Severina Limited | Professional & scientific | 2021 |
| Sewa (UK) Limited | Wholesale & retail | 2003 |
| SEY & Morr Ltd | Wholesale & retail | 2020 |
| SEY Global | Education | 2016 |
| Seychelle Court Management Company Limited | Households | 1973 |
| Seyyon Verses Limited | Real estate | 2024 |
| SF Brothers Limited | Transport & logistics | 2024 |
| SF Data Ltd | Information & communication | 2023 |
| SF Marcut Ltd | Manufacturing | 2024 |
| SFR Enterprise Trading Ltd | Wholesale & retail | 2019 |
| SFS Consultancy Limited | Arts & recreation | 2013 |
| SFV Advisory Services UK Ltd | Professional & scientific | 2022 |
| SG Dental Supplies Ltd | Manufacturing | 2021 |
| SG Software Solutions Limited | Information & communication | 2013 |
| SG1 Holdings Limited | Real estate | 2020 |
| SGC Publishing Consultants Limited | Information & communication | 2019 |
| SGI Sakkara Holding Limited | Administrative & support | 2014 |
| SGJ Consulting House Ltd | Professional & scientific | 2019 |
| SGP Steel Erections Limited | Manufacturing | 2003 |
| Sgtw Management Ltd | Households | 2025 |
| SH (2013) UK Ltd | Financial services | 2013 |
| SH Private Limited | Real estate | 2016 |
| SH Solution Group Ltd | Administrative & support | 2026 |
| SH42CW Limited | Households | 1995 |
| Shaan Construction Group Ltd | Construction | 2025 |
| Shabuki Limited | Real estate | 2013 |
| Shadbolt Network Ltd | Professional & scientific | 2025 |
| Shades of Noir Ltd | Information & communication | 2023 |
| Shadi Bakery Ltd | Hospitality | 2020 |
| Shady Tints Ltd | Wholesale & retail | 2015 |
| Shaftsbury Gate Residents Management Company Limited | Households | 2012 |
| Shah Brothers Impex Limited | Hospitality | 2025 |
| Shah Cheers Ltd | Hospitality | 2025 |
| Shah Karahi Ltd | Hospitality | 2022 |
| Shahid Nexus Ltd | Transport & logistics | 2025 |
| Shahjee Enterprise Limited | Transport & logistics | 2016 |
| Shahzad & Sons Ltd | Professional & scientific | 2025 |
| Shahzad Trading Limited | Professional & scientific | 2026 |
| Shaily Innovations Ltd | Wholesale & retail | 2020 |
| SHAIUK1 Ltd | Wholesale & retail | 2020 |
| Shaka Services | Health & social care | 2003 |
| Shake & Grill (South East) Limited | Hospitality | 2024 |
| Shake IT Ltd | Administrative & support | 2024 |
| Shakes & Scoops Ltd | Hospitality | 2024 |
| Shaketheworld Ltd | Information & communication | 2025 |
| Shakscosmetic Ltd | Wholesale & retail | 2024 |
| Shakti Brighton Limited | Wholesale & retail | 2002 |
| Shaktima Holdings Limited | Construction | 2025 |
| Shaktima Limited | Construction | 2025 |
| Shalex Counselling and Psychotherapy Ltd | Wholesale & retail | 2020 |
| Shali Fashion Ltd | Wholesale & retail | 2023 |
| Shalom Health & Social Care Ltd | Administrative & support | 2022 |
| Shaluj Limited | Health & social care | 2026 |
| Shamali Traders Ltd | Wholesale & retail | 2023 |
| Shamira and S Properties Limited | Real estate | 2023 |
| Shamira and Sons Properties Ltd | Administrative & support | 2007 |
| Shamira and Sons UK Ltd | Wholesale & retail | 2007 |
| Shan Convenience Store Limited | Wholesale & retail | 2026 |
| Shan's Bubbly Ltd | Health & social care | 2022 |
| Shandong Cmdr Fitness Equipment Co., Ltd | Wholesale & retail | 2024 |
| Shanghai Legacy Limited | Hospitality | 2025 |
| Shangqi International Trading Ltd | Manufacturing | 2025 |
| Shangqi New Energy Co., Ltd | Manufacturing | 2025 |
| Shanklin House Maintenance Limited | Households | 1973 |
| Shanstyless Limited | Other services | 2025 |