| Line20 Digital | |
| Line9 Internet UK | Buckinghamshire |
| Lineal Software Solutions Ltd | Devon |
| Linear Diagnostics Ltd | |
| LineTen Technology | |
| Linetime Ltd | West Yorkshire |
| Lineup Ninja | |
| Lingo24 Ltd | Edinburgh |
| Linix Ltd | Merseyside |
| Link Communications Systems Ltd | |
| Link Digital Ltd | |
| Link Microtek Ltd | Hampshire |
| Link Radio Services | Norfolk |
| Link-Tel Communications Ltd | Glasgow |
| Linkcheck Ltd | Bristol |
| LinkedTrade Technologies Ltd | Greater London |
| LinkGevity Ltd | |
| LinkIT | Hampshire |
| Links Broadcast | Essex |
| Linkup Social Ltd | |
| LinkUp Technology Ltd | Leicestershire |
| Linkwood Software & Systems | Surrey |
| Linnworks | |
| Lintel Software Consultancy | Cheshire |
| Linter Consulting | West Sussex |
| Lintron Electronics Ltd | Northumberland |
| Linux Internet | Tyne and Wear |
| LinuxWaves.com | Derbyshire |
| Linwave Technology | Lincolnshire |
| Linx Productions | |
| Linxcom UK | Northamptonshire |
| Linxdesign Internet Ltd | Staffordshire |
| Lion Enterprises Ltd | Berkshire |
| Liopa | |
| Liquid | Wiltshire |
| Liquid Bubble | |
| Liquid Creative Agency | |
| Liquid Light Ltd | East Sussex |
| Liquid Technologies Ltd | West Yorkshire |
| Liquid Voice Ltd | West Yorkshire |
| Liquidigloo Ltd | Cheshire |
| LiquidLogic | West Yorkshire |
| LiquidSix Hosting | West Sussex |
| Lisa Web Agency | |
| Lisarb Energy | |
| LispWorks Ltd | Cambridgeshire |
| Listed Website Design | |
| listening247 | |
| Lister Communications Ltd | Gloucestershire |
| Liten Media | |