| Shaw Commerce Ltd | Wholesale & retail | 2026 |
| SHE IS Gold | Education | 2025 |
| Sheard Fine Jewellery Ltd | Wholesale & retail | 2016 |
| Shearglade Limited | | 1987 |
| Sheerluxe Cleaning Services Ltd | Administrative & support | 2024 |
| Shell Propco 1 Ltd | Real estate | 2025 |
| Shellow Cross Farms Limited | Real estate | 1974 |
| Shen Computer Solution Limited | Wholesale & retail | 2004 |
| Shenfield Construction Limited | Construction | 2003 |
| Sheriff Capital Ltd | Financial services | 2025 |
| Sherman Accounting & Training Limited | Professional & scientific | 2002 |
| Sherrygreen Homes Ltd | Construction | 2006 |
| Shieldbyte Ltd | Information & communication | 2025 |
| Shimlex Enterprises Ltd | Wholesale & retail | 2025 |
| Shinet Care Limited | Health & social care | 2020 |
| Shinymart Ltd | Wholesale & retail | 2026 |
| Ship Buy Limited | Wholesale & retail | 2026 |
| Shipper Ltd | Wholesale & retail | 2024 |
| Shipzane Limited | Wholesale & retail | 2021 |
| Shire Controls EOT Ltd | Professional & scientific | 2023 |
| Shirin Mahal Sweets and Bakers Ltd | Wholesale & retail | 2023 |
| Shivam Limited | Real estate | 1994 |
| Shivum Limited | Health & social care | 2006 |
| Shkp Limited | Construction | 2007 |
| Shoepepper Limited | Professional & scientific | 2005 |
| Sholly IT Limited | Other services | 2007 |
| Shop Direct NOW Ltd | Wholesale & retail | 2024 |
| Shop Fleet Ltd | Wholesale & retail | 2025 |
| Shop Shine Mart Ltd | Wholesale & retail | 2026 |
| Shopdrop Ltd | Wholesale & retail | 2025 |
| Shopeedreams Ltd | Wholesale & retail | 2025 |
| Shopistry Ltd | Wholesale & retail | 2025 |
| Shopley Global Ltd | Wholesale & retail | 2026 |
| Shoppico Ltd | Wholesale & retail | 2025 |
| Shoppixo Ltd | Wholesale & retail | 2025 |
| Shoreline Aviation & Marine Limited | Transport & logistics | 2000 |
| Shortspluse Limited | Information & communication | 2025 |
| Shosky U.K. Limited | Wholesale & retail | 2005 |
| Shot Farm Commercial Parking Ltd | Transport & logistics | 2005 |
| Shpfusion Limited | Manufacturing | 2024 |
| SHRED4SECURITY Limited | Administrative & support | 2001 |
| Shukhar Shopping Limited | Wholesale & retail | 2004 |
| SI AI WEI Trading Co., Ltd | Wholesale & retail | 2025 |
| Sibley Chew Limited | Professional & scientific | 2008 |
| SID Hutchby & Sons Limited | Manufacturing | 2004 |
| Sidd Agency Ltd | Wholesale & retail | 2022 |
| Sienna Mayah Property Services Limited | Real estate | 2026 |
| Signalcom Limited | Construction | 2007 |
| Signalling and Rail Interfaces Ltd | Professional & scientific | 2026 |
| Signartistry Ltd | Administrative & support | 2025 |
| Signature Financial Consultants Ltd | Professional & scientific | 2002 |
| Signature SOL Ltd | Manufacturing | 2026 |
| Silhouette DU Barry | | 1994 |
| Silk Touch Creations Ltd | Wholesale & retail | 2017 |
| Silks Court (Barclay Road) Management Company Limited | Real estate | 1987 |
| Silver City Estates Limited | Real estate | 1998 |
| Silver City Holdings Limited | Professional & scientific | 1998 |
| Silver Magic Limited | Wholesale & retail | 2003 |
| Silver Medics Ltd | Health & social care | 2023 |
| Silver Wolf Systems Limited | Information & communication | 1998 |
| Silverback Recruitment Ltd | Administrative & support | 2026 |
| Silvercrest Computer Supplies Limited | Professional & scientific | 1990 |
| Silverisland TV Ltd | Information & communication | 1999 |
| Silvermist Properties (Chelmsford) Limited | Construction | 2005 |
| Silvernet Solutions Limited | Information & communication | 1998 |
| Silverpak Ltd | Wholesale & retail | 2024 |
| Silverton Recycling Limited | Water & waste | 2007 |
| Sima Stays Ltd | Real estate | 2023 |
| Simeon & Associates Limited | Professional & scientific | 2017 |
| Simeph Services Limited | Administrative & support | 2015 |
| Simon Woods Joinery Limited | Administrative & support | 2007 |
| Simpli Ltd | Extraterritorial | 2012 |
| Simply Engineered Limited | Professional & scientific | 2007 |
| Simply Furnished Ltd | Wholesale & retail | 2009 |
| Simply Heavenly Foods Ltd | Wholesale & retail | 2003 |
| Simply Stored Limited | Extraterritorial | 2007 |
| Simply Washrooms Ltd | Administrative & support | 2006 |
| Simpson Adeniji Limited | Health & social care | 2025 |
| Simpsons Plumbing and Electrical Limited | Construction | 2003 |
| Sims Legacy Holdings Ltd | Financial services | 2026 |
| Simzontech Limited | Wholesale & retail | 2026 |
| Sin-D Property Ltd | Real estate | 2022 |
| Sinafoods Limited | Hospitality | 2016 |
| Singh Venetian Plaster Ltd | Construction | 2024 |
| Sira Properties Ltd | Real estate | 2007 |
| Sirco Controls Limited | Manufacturing | 1960 |
| Sirius Trade Pro Ltd | Energy | 2024 |
| Sisidupeshow Ltd | Information & communication | 2024 |
| SIT Paws Play Ltd | Agriculture & fishing | 2025 |
| Sitech (London) Limited | Construction | 2002 |
| Sitelinks Support Systems Limited | Professional & scientific | 1997 |
| Siticons Limited | Information & communication | 2026 |
| Sitricia Limited | Real estate | 1955 |
| Siwic Ltd | Wholesale & retail | 2026 |
| Sixty Events Ltd | Other services | 2024 |
| SJ Holistic Leading Healthcare Provider Limited | Health & social care | 2018 |
| SJF Manufacturing Limited | Professional & scientific | 2025 |
| SJH Air Conditioning Services Limited | Construction | 2011 |
| Sjje Services Ltd | Health & social care | 2019 |
| SJK Planning Limited | Professional & scientific | 2005 |