| Spacetime Development Ltd | |
| SpaceVee | |
| Spades Media Ltd | |
| Spaera Ltd | |
| Span Software Consultants Ltd | Cheshire |
| SpanSoft | Fife |
| SPARK Business Incubator Wolverhampton | |
| Spark! Data Systems Ltd | |
| Spark10 Ltd | |
| Sparkbox | |
| Sparkol Ltd | |
| Sparkstone Creative | West Lothian |
| Sparkstone Technology | Hampshire |
| SparkTech | |
| Sparkz Network Ltd | Merseyside |
| SPARTA Biodiscovery | |
| Sparta Global | |
| Sparx Maths | |
| Spasoft | Wiltshire |
| Spatial Flow Ltd | |
| Spatialest | Causeway Coast and Glens |
| SPC International Ltd | Berkshire |
| SPD Technology | |
| Spearhead Training Group Ltd | Oxfordshire |
| Special Design Studio | |
| Special Projects | |
| Specialist Marketing Agency | |
| Specialist Valve Services Ltd | |
| Specific Componetns | Greater Manchester |
| Speckle Systems | |
| Speckled Frog | Cambridgeshire |
| Specle Ltd | |
| Specto Natural Ltd | |
| Spectra Displays Ltd | Cambridgeshire |
| Spectra Group (UK) Ltd | Herefordshire |
| Spectra Security Ltd | Greater Manchester |
| SpectralWorks | Cheshire |
| Spectrum Networks Solutions Ltd | |
| Speech Empowered Computing | Flintshire |
| Speech Graphics | |
| Speechmatics | |
| Speechmatics | |
| Speedie Consultants Ltd | Kent |
| Speedwell Software | Cambridgeshire |
| Spektrix | |
| Spex Capital Ltd | |
| Spey Software Ltd | |
| Sphaera Training Systems | Swansea |
| Sphere Bio | |
| Sphere Fluidics | |