Dublin Airport’s Terminal 2 oversees all of the long-haul flights to and from the airport, leaving Terminal 1 to handle shorter connections to and from cities in the surrounding region and greater Europe. With this in mind, passport control is part of the equation in T1, but not to the extent as in its newer counterpart.
If you are travelling within the EU, or within the Schengen Area, you will not need to submit to passport control when you land. In this case, you simply arrive at the airport, stop by the luggage carousel and proceed through the arrivals area. Choose the blue line if you have nothing to declare. Otherwise, stop by the red checkpoint.
Anyone who is flying in from outside of the EU or Schengen Area will have to submit to passport control once they land. In this case, there are two channels to choose from. The blue channel is for arrivals who need to be stamped into the EU but don’t have anything to declare.
Customs declarations can be made at red check points. Random screenings make it worth declaring anything you are unsure of. Simply fill out the customs declaration form and present it to the officer at the check point.