| Scottish Web Design | Fife |
| Scottish-Hosting.com | Glasgow |
| Scottsdale Building Systems | Suffolk |
| Scottsdale Lifetime Partners | |
| ScottSpace Ltd | |
| Scottweb Design | Suffolk |
| Scout Websites | |
| SCP Computers Ltd | |
| Scrapbook Development Ltd | |
| ScraperWiki Ltd | Merseyside |
| Screaming Frog Ltd | Oxfordshire |
| Screen Pages | Surrey |
| ScreenCloud | |
| Screendragon | |
| Screenlane | |
| Screenlight | |
| Screenloop Ltd | |
| Scribble & Ink | Devon |
| Scribbling Media Ltd | |
| Scribeless | |
| Scribetech (UK) Ltd | Greater London |
| Scripta Therapeutics | |
| Scriptic | |
| Scruffy Biotech Ltd | |
| SCS Technology Solutions Ltd | Lincolnshire |
| SCube Digital Ltd | |
| Scurri Ltd | |
| SDK Solutions | Berkshire |
| SDMS Ltd | Shropshire |
| SDS Click | |
| SDS Ltd | |
| SDS Softwares | West Midlands |
| Sdt Ltd | Berkshire |
| Sea | |
| Sea Dragon Design Ltd | Kent |
| SEA Token CIC | Glasgow |
| Seagull Designs | |
| SEAMCO | Northamptonshire |
| Seamcor | |
| Search and More Ltd | |
| Search Aumen | |
| Search Candy Ltd | |
| Search Click Digital | |
| Search Consultancy | |
| Search Creative | |
| Search Creative SEO | |
| Search Engine Links | |
| Search Engine Rankings | |
| Search Engineer | Cumbria |
| Search Intelligence Ltd | |