Originally Posted by YVR Cockroach
Don't confuse immigration and customs. Yes, there are both between Italy and the U.K. as the U.K. has not acceded to the Treaty of Schengen (customs/immigration union).
As you said... Don't confuse immigration and customs!
Schengen is about immigration. It has nothing to do with customs. With certain exceptions (which I won't go into here) there are no customs controls within the European Union. Customs controls were abolished in 1992 - that's when we started having a blue channel at airports in addition to the usual green and red ones.