Where to clear US immigration before arriving in the USA?

Several airports in Canada and Ireland allow you to clear US immigration before your arrival in the United States. Here's how it works.

How to clear US immigration before arriving in the United States

If you’re traveling to the United States, you must pass through US immigration when you arrive. However, several airports around the world let you clear US immigration BEFORE your flight. This system is called “Preclearance.”
In effect, the US border moves to your departure country. Preclearance works exactly like immigration screening at a US airport. US immigration officers complete the formalities before you board—the same ones normally done on arrival. You’ll enter the United States before you even get on the plane.
Once you land in the United States, you skip immigration entirely—it’s already done. You arrive like you’re on a domestic flight. It feels strange the first time.
The benefit? You can save up to 2 hours, especially if it’s your first time entering the United States.

Preclearance operates at 15 airports worldwide, with a total of 600 US immigration officers. To use it, you must depart from one of these airports:

Dublin and Shannon in Ireland. If you fly from Paris to New York on Irish airline Aer Lingus, you’ll connect through Dublin. There you can use Preclearance before your US flight. Preclearance is also available if you depart Dublin on Norwegian, American Airlines, United Airlines, or Delta Airlines.
All major Canadian airports: Toronto, Montréal, Ottawa, Vancouver, Calgary, Edmonton, Halifax, Winnipeg, and Victoria. If you fly Air Canada through Toronto or Montréal to the United States, you’ll clear US immigration in Canada before boarding your US flight.
Abu Dhabi in the United Arab Emirates. If you fly Etihad Airways, you can also use Preclearance.
Nassau in the Bahamas, Bermuda, and Aruba. You’re unlikely to fly through these islands, but they’re part of the program too.

For Preclearance to operate at an airport outside the United States, both governments must agree. France, for example, doesn’t want US immigration officers based on its soil. So don’t expect Preclearance at Paris anytime soon. European governments cite sovereignty and reciprocity concerns.
In 2015, US authorities proposed Preclearance at Brussels Airport and both governments seemed willing. But implementation has been delayed year after year. It was supposed to happen in 2017, then 2018. The issue is still being discussed in 2026.