| Liftrank Media Ltd | |
| Light IT Global | |
| Light Software | |
| Lightbox Digital | West Midlands |
| Lightcast Discovery | |
| Lightcast Discovery Ltd | |
| Lightflows Ltd | Surrey |
| Lightfoot Solutions Group Ltd | |
| Lighthouse | |
| Lighthouse Visual Communications Ltd | |
| LIGHTOX Ltd | |
| Lightpoint Medical | |
| Lightrock | |
| LightUpp | |
| LiGo Electronics Ltd | Glasgow |
| Lihou Technical & Software Services | West Midlands |
| Like Digital | Greater London |
| Like Mobile | |
| Like Technologies | |
| Likin'IT!.. Ltd | Greater Manchester |
| Lilac Software Ltd | Buckinghamshire |
| Lilo Web Design | |
| Lily Comms Ltd | West Yorkshire |
| Lima Technology | Greater Manchester |
| Limbtec | Devon |
| Lime Circles | |
| Lime Microsystems Ltd | Surrey |
| Lime Software Ltd | Essex |
| Limeapps | |
| Limely Ltd | |
| Limerston Capital Partners Ltd | |
| Limesharp | |
| Limetree Consultancy Ltd | |
| Limeup | |
| Liminal Design Cornwall | Cornwall |
| Limitless Technology Group Ltd | |
| Limitless.app | Cambridgeshire |
| LimitState Ltd | South Yorkshire |
| Linaro Ltd | |
| Linc IT | Lincolnshire |
| LINC Scotland | |
| Lincoln Web Enterprises Ltd | |
| Lincolnshire PC Solutions | Lincolnshire |
| Linctel | Lincolnshire |
| Lindaven Services Ltd | Nottinghamshire |
| Linde plc | |
| Lindsay Finance Ltd | |
| Lindsay Smith | |
| Lindy | North Yorkshire |
| Lindy Electronics Ltd | North Yorkshire |