| Stuff and Nonsense Ltd | Flintshire |
| Sturgeon Ventures, LLP | |
| STURQ Associates | |
| STV Group plc | |
| Stylefrog Creative | Northamptonshire |
| StyleTech Solutions Ltd | East Riding of Yorkshire |
| Stylistic Design Studio & Shop | |
| Stylographic Design | |
| Styloola | |
| Stylus Design | Shropshire |
| Stylus Networks Ltd | |
| Subak | |
| Subbly | |
| Subism Ltd | |
| Sublime by Design Ltd | Somerset |
| Subly | |
| Submarine Ltd | Channel Islands |
| Submission Technology | |
| Substrakt | West Midlands |
| Subx Technology | Greater London |
| Subzerostudio Ltd | |
| Succeed Consultancy | Hertfordshire |
| Success Corporation | Lincolnshire |
| Success Local Ltd | |
| Suffolk Automation | Suffolk |
| Suffolk Mac User Group | Suffolk |
| Suffolk New College | |
| Sufi Engineering | |
| Sugar Creative | |
| Sugar Rush | |
| SugaROx Ltd | |
| SugarShaker Enterprises Ltd | |
| Sugi | |
| Suilven Associates | Herefordshire |
| Suisoft Ltd | West Yorkshire |
| SuiteCRM | |
| Sum and Substance Ltd | |
| Suma Software Solutions | |
| Sumac UK Ltd | Essex |
| Sumdog | |
| Sumlock Bondain (EA) Ltd | Norfolk |
| SummerEyes Technology Ltd | |
| Summit Creative | |
| Summit Medical Group | |
| Summit7 Ltd | Worcestershire |
| Summitsoft Ltd | Berkshire |
| Summize Ltd | |
| Sumo Digital Ltd | South Yorkshire |
| SumUp | |
| Suna Comminication | Greater London |