| Smartzi Ltd | |
| SMCO | Devon |
| SME Capital | |
| SME SEO Agency | |
| SME Solutions Ltd | East Sussex |
| Smedvig Capital | |
| Smedvig Ventures Ltd | |
| Smerky | |
| Smile Data Security Ltd | |
| Smile IT Solutions | |
| SMIS Ltd | Worcestershire |
| Smith Design Solutions Ltd | South Lanarkshire |
| Smith Myers | Bedfordshire |
| Smith+Nephew | |
| SMK Digital Ltd | |
| SML Solutions Ltd | |
| Smoking Rocket Media Ltd | |
| Smoof | |
| Smooth Websites Ltd | |
| Smoothwall Ltd | |
| SMR Computer Services | Buckinghamshire |
| SMR Electronics Ltd | Wiltshire |
| SMS | Cheshire |
| SMS Electronics | Nottinghamshire |
| Sms marketing | Greater Manchester |
| SMS Research | |
| SMSCarrier | West Lothian |
| SMTP Software | Isle of Man |
| SN Systems Ltd | Bristol |
| SNA Software Systems | Cornwall |
| Snake Lane Design | |
| Snap Design & Digital | |
| Snap Designs | Greater London |
| Snap Vision Ltd | Greater London |
| Snape Computers Ltd | Greater London |
| Snapify Ltd | |
| Snaptree Ltd | |
| SnatchDigital | |
| Sneakytrick | North Yorkshire |
| SNIB Ltd | |
| Snippet Digital | |
| Sniro Ltd | |
| Snooze Technologies UK Ltd | |
| Snotor Ltd | |
| Snowball Impact Management Ltd | |
| Snowdrop Solutions Ltd | |
| Snowplow Analytics | |
| Snowstorm Technologies (UK) Ltd | Buckinghamshire |
| SNS Internet | Derbyshire |
| So Energy Trading Ltd | |