| Sebastian Mocan Ltd | Construction | 2018 |
| Second Edit Boutique Ltd | Wholesale & retail | 2026 |
| Second Sight Pictures Limited | Other services | 2010 |
| Second Wave Store Ltd | Wholesale & retail | 2023 |
| Secret Garden TD Ltd | Wholesale & retail | 2019 |
| Secure Networking Limited | Information & communication | 2016 |
| Secure Recognition Limited | Manufacturing | 2013 |
| Securitalis Ltd | Information & communication | 2019 |
| Security Advice Limited | Administrative & support | 2013 |
| Security Blend Books Limited | Information & communication | 2024 |
| Security Ninja Ltd | Information & communication | 2024 |
| Sedra Investments Limited | Extraterritorial | 1999 |
| Seedlings PRE School Woking Ltd | Education | 2013 |
| Seeuk Travel Limited | Administrative & support | 2015 |
| Sehaj Limited | Transport & logistics | 2024 |
| Sejs Consulting Ltd | Professional & scientific | 2022 |
| Selbooks Ltd | Wholesale & retail | 2016 |
| Seldram Supplies (Camberley) Limited | Wholesale & retail | 1989 |
| Seldram Supplies (Oxford) Limited | Wholesale & retail | 1988 |
| Seldram Supplies Limited | Administrative & support | 2011 |
| Self Publishing Solutions Ltd | Information & communication | 2026 |
| Sellum Ltd | Information & communication | 2025 |
| Selyum Homes Limited | Extraterritorial | 2024 |
| Semmco Group Limited | Financial services | 2018 |
| Semmco Limited | Manufacturing | 1992 |
| Semmco LPS Limited | Manufacturing | 2014 |
| Send (Priory Fields) Management Company Limited | Households | 2005 |
| Send Plumbing & Heating Ltd | Construction | 2020 |
| Send Secretarial Limited | Professional & scientific | 2001 |
| Senior Care Limited | Health & social care | 2025 |
| Sense Services Limited | Construction | 2023 |
| Senthra Solutions Limited | Professional & scientific | 2023 |
| Sentient Leaf Limited | Information & communication | 2013 |
| Serenity Activities Ltd | Health & social care | 2025 |
| Serious Entertainment Group Ltd | Arts & recreation | 2020 |
| Serrulata Limited | Administrative & support | 2022 |
| Serrulata Services Limited | Hospitality | 2026 |
| Serversys Capital Management Ltd | Financial services | 2013 |
| Serversys Group Limited | Professional & scientific | 2001 |
| Serversys Limited | Information & communication | 1999 |
| Service Transformation Limited | Professional & scientific | 2009 |
| SES 4 Star Energy Limited | Energy | 2022 |
| Settrend Limited | Other services | 2025 |
| Seven & Co Studio Ltd | Professional & scientific | 2020 |
| Seven Acres FIC Limited | Financial services | 2020 |
| Seven Motors Group Limited | Wholesale & retail | 2025 |
| Sevenpoint Engineering Solutions Limited | Professional & scientific | 2023 |
| Seyco Ltd | Professional & scientific | 2024 |
| Seylind Limited | Information & communication | 2018 |
| Seymour Solutions Limited | Professional & scientific | 2022 |
| SF Oral Care Ltd | Health & social care | 2024 |
| SFP Dreams Limited | Arts & recreation | 2016 |
| SFP Shows Limited | Arts & recreation | 2014 |
| SFP Sunny Limited | Arts & recreation | 2014 |
| SGC24 Limited | Households | 2025 |
| Sggauto Ltd | Wholesale & retail | 2025 |
| SGI Group Limited | Financial services | 2005 |
| Sgll Consultants Limited | Professional & scientific | 2017 |
| SH Event Consultancy Limited | Administrative & support | 2019 |
| SH4FI House Ltd | Real estate | 2019 |
| Shadowbandit Ltd | Information & communication | 2021 |
| Shahid Global Traders Ltd | Wholesale & retail | 2025 |
| Shahid Sons Enterprises Limited | Wholesale & retail | 2025 |
| Shaka Franchise Consultants Limited | Wholesale & retail | 2019 |
| Shakan Foods Limited | Hospitality | 2015 |
| Shalwood Limited | Real estate | 2022 |
| Shams Homes Ltd | Real estate | 2026 |
| Shantou Unigrace UK Ltd | Wholesale & retail | 2020 |
| Shape New Ideas Limited | Professional & scientific | 2012 |
| Shapeblue Employee Ownership Trustees Limited | Professional & scientific | 2024 |
| Sharaz Homes (North East) Ltd | Construction | 2021 |
| Sharaz Homes Ltd | Construction | 2002 |
| Shardsec Ltd | Information & communication | 2025 |
| Shareground Property Management Limited | Real estate | 1987 |
| Sharma Courier Limited | Transport & logistics | 2016 |
| Sharon Allen Research Ltd | Professional & scientific | 2017 |
| Shaw Communications Limited | Professional & scientific | 2008 |
| Shaz Auto Group Limited | Administrative & support | 2018 |
| Shaz Chauffeur Services Ltd | Transport & logistics | 2025 |
| Shazad Homes Limited | Real estate | 2016 |
| SHE Burger Ltd | Hospitality | 2024 |
| SHE Drives Motors Ltd | Wholesale & retail | 2025 |
| Sheer Protection Limited | Administrative & support | 2023 |
| Sheerwater Landscapes & Resin Ltd | Administrative & support | 2024 |
| Sheila Binns Designs Ltd | Professional & scientific | 2011 |
| Shelter Holding Limited | Professional & scientific | 2025 |
| Shenton Gate Management Company Limited | Real estate | 2004 |
| Shepperton Studios Accommodation Ltd | Hospitality | 2022 |
| Shere Investment Limited | Professional & scientific | 2009 |
| Sherehe Haus Ltd | Administrative & support | 2026 |
| Sherif Dabbour Ltd | Health & social care | 2026 |
| Sherwoods International Holding Ltd | Administrative & support | 2013 |
| Sheywood Property Investments Ltd | Real estate | 2026 |
| Shield Construction Ltd | Construction | 2016 |
| Shifa Network CIC | Education | 2026 |
| Shift GMC Ltd | Wholesale & retail | 2015 |
| Shift Public Relations Limited | Professional & scientific | 2010 |
| Shifu Ltd | Transport & logistics | 2023 |
| Shilco Limited | Professional & scientific | 1999 |
| Shin Asian Food Ltd | Hospitality | 2023 |