| Suncombe Ltd | |
| Sundance Multiprocessor Technology Ltd | Buckinghamshire |
| Sunday Launch Ltd | Gloucestershire |
| Sunderland Software City | |
| Sundose Ltd | |
| Sundown Solutions | |
| Sungold Systems Ltd | Bedfordshire |
| Sunlight Technologies Ltd | |
| Sunny Bank Mills | West Yorkshire |
| Sunpower Group Holdings Ltd | Berkshire |
| Sunpower UK | |
| Sunray Media | |
| Sunrise Computer Ltd | Fife |
| SunRise IT Solutions | Cheshire |
| Sunrise Software Ltd | Greater London |
| Sunrise Systems | Edinburgh |
| Sunsave | |
| Sunshine Communications | |
| Sunstone Communication Ltd | |
| Sunswap Ltd | |
| Supake Ltd | Derbyshire |
| Super Digital Ltd | |
| Super Payments Ltd | |
| Super Payments Ltd | |
| Superb Digital Ltd | Bristol |
| Superbase Developers plc | Surrey |
| Supercede Technology Ltd | |
| SuperControl Ltd | Dumfries and Galloway |
| Supercool Design | West Midlands |
| Supercritical Tech Ltd | |
| Superfast IT | |
| Superflows | |
| Superfluid Finance Ltd | |
| Superlayer | |
| Supermassive Games | Surrey |
| SuperOffice Software Ltd | Bedfordshire |
| Superscript | |
| Supersede Media Ltd | |
| SupersizedSEO | Greater London |
| Supple Ltd | |
| Supplies Direct Ltd | Cambridgeshire |
| Supply Design Ltd | |
| Supply@ME | |
| Supplyline Auto ID Ltd | West Sussex |
| Support To Perform | Belfast |
| SupportKey Ltd | Glasgow |
| Supportworks | Greater London |
| Supreme Fintech | |
| Sure Ltd | |
| Sure Valley Ventures | |