| sa.global | Caerphilly |
| SAA Consultants | Devon |
| SAA Consultants Ltd | |
| SaaS Developers | |
| Saberr | |
| SableBio Ltd | |
| Sabre Advanced Microelectronics Ltd | Oxfordshire |
| Sabre Systems | South Lanarkshire |
| Sabretooth Designs | West Yorkshire |
| Sads Ltd | Kent |
| Safe Ventures (UK) Ltd | Herefordshire |
| Safe Websites | |
| Safenames | Buckinghamshire |
| Safeserve.com Ltd | |
| SafeSign Technologies Ltd | |
| Safesmart Ltd | |
| Safetech Ltd | |
| SafeToNet | |
| Safety Systems Distribution Ltd | |
| SafetyDetectives | |
| SafetyNet Systems Ltd | Ceredigion |
| SafetyNet Technologies Ltd | |
| Saffe | |
| Safi | |
| Saga Labs Ltd | |
| Sagacity Solutions | |
| Sage Group plc | Tyne and Wear |
| Said Digital | Greater London |
| Saint IT Ltd | |
| Saint Nicolas Ltd | |
| Sairo Studios Ltd | |
| Saitech UK Ltd | Cornwall |
| Sakisoft Ltd | |
| Sakura Brae | |
| Salary Finance, Inc. | |
| SALCS Installations Ltd | |
| Sales Plus Consultants Ltd | |
| SalesAR | |
| SalesEnzine Ltd | |
| Salesfire | |
| SalesforceBen.com | |
| SalesGenomics | |
| Salespiders | |
| SalesSeek | |
| Salford City College | |
| Salience Labs | |
| Salient Systems Ltd | Tyne and Wear |
| Salocin Group Ltd | |
| Salon Tracker | |
| Salt Search Ltd | |