| Spire Hosting Ltd | Greater London |
| Spire Technology Ltd | Dorset |
| Spirea Ltd | |
| Spirea Ltd | |
| SPJ Marketing | South Yorkshire |
| Splash Damage Ltd | Greater London |
| Splashweb | Cambridgeshire |
| Splicecom | Hertfordshire |
| Splyt Technologies Ltd | |
| Spoke | |
| Spoko | |
| Sponge Group Holdings Ltd | |
| SporeGen Ltd | |
| Sport Tech Hub | Greater London |
| Sportech plc | |
| Sports Loft | Greater London |
| SportSoft (UK) Ltd | |
| Spot Intelligence | |
| Spotbeam Communications | Essex |
| Spotler | |
| Spotless Interactive | |
| Spotlight Studios Ltd | |
| Spoton Software Training | Lincolnshire |
| Spotted Zebra | |
| Spotty Dog Digital Marketing | |
| Springer Marketing Services Ltd | Cornwall |
| Springpod | |
| Springwise | |
| Springwood Web Solutions | Merseyside |
| SPRINT - SPace Research and Innovation Network for Technology | |
| Sprint Computer Repairs Ltd | West Lothian |
| Sprintbase | |
| Sprive | |
| Sprout.ai | Greater London |
| SPT Labtech Ltd | |
| SPTS Technologies Ltd | |
| Spudd Mobile Ltd | |
| Spusu UK Ltd | |
| Sputnik Digital | Greater Manchester |
| SpyBiotech | Oxfordshire |
| SpyBioTech Ltd | |
| SQLServerCentral | Cambridgeshire |
| SqrOne Ltd | |
| Square 1 Communications Ltd | Wiltshire |
| Square One | Gloucestershire |
| Square Systems | Bristol |
| Squarebird Agency Ltd | |
| Squibble Ltd | |
| Squire Technologies Ltd | Dorset |
| Squire Technologies Ltd | |