Ireland is one of only six countries worldwide to offer U.S. Preclearance, a service that allows travelers to complete all U.S. immigration and customs checks before departing from Ireland. This system is available at Dublin and Shannon Airports and is promoted as a key benefit for those flying with Aer Lingus.
According to Aer Lingus, the main advantage of U.S. Preclearance is that passengers can avoid long immigration lines upon arrival in the United States. The airline states, "When you land in the U.S., the last thing you want is to wait in long immigration lines. But with U.S. Preclearance at Dublin Airport, you won’t have to. You’ll complete all your immigration checks before you even leave Ireland. So, when you land at your U.S. destination, all you need to do is grab your bags and head off, with no customs or security lines to navigate."
Aer Lingus also highlights additional benefits such as more time for relaxation before flights and a smoother airport experience overall: "With Preclearance successfully completed, you’ve earned some downtime before your flight. No need to rush through the airport—you can take your time at the terminal, grab a coffee, do a little shopping, or even catch up on some reading."