Washington DC Dulles - incoming from Ireland Question

We had a connection at Dulles a couple of years ago and did not make it. We were traveling Rome - IAD - SFO. There was about 2 hours as I recall for the connection, but thunderstorms delayed landings and 6 international flights had to process simultaneously. It was a mess. We arrived 6 hours late in SFO.

I do not recall changing terminals (might have done by shuttle bus?) but of course we went through passport control and customs at IAD. Once you are through customs and passport control you are still behind security so no re-entry. They will shuttle you as needed to another terminal.

When you fly from Dublin to the United States, you go through customs/immigration on the Dublin side. So when you get off the plane in DC, it's just a matter of getting to your next gate- you don't have to do customs/immigration again. There are few airports where it works like this... Dublin just happens to be one of them.

Here's more information:

https://www.dublinairport.com/at-the-airport/passenger-information/us-preclearance-facility

We flew United from Dublin through Dulles last month. Because you will clear US passport and customs in Dublin, your arrival at IAD is effectively a domestic flight and you won't have to collect/re-check your bags. Unless you are connecting to a United Express flight, both arrival and departure will be in Terminal C/D (that's actually one long, connected, terminal.) Unless the DUB flight is significantly delayed, you'll have no trouble making your connection.
That said, the US "Pre-clearance" process at DUB was time-consuming, including 2 separate carry-on screenings and some slow-moving lines. (We were on the flight departing around 1:00 p.m.) The signage for US flights is hard to miss. More info here:
https://www.dublinairport.com/at-the-airport/passenger-information/us-preclearance-facility
I don't recall the recommended time before flight departure for arrival at DUB, but I wouldn't be comfortable with anything less than 2 hours (plus time you might spend in the large Duty-Free zone that you'll pass through on the way to Pre-Clearance.)

[Sorry for duplicating some of the replies above; I was still typing when they posted.]

Because you will clear US passport and customs in Dublin, your arrival at IAD is effectively a domestic flight and you won't have to collect/re-check your bags.

And that will explain why the agent could say both flights are at the same terminal. It's just like connecting from a domestic flight to another domestic flight.

Super helpful! Thank you, everyone!

Since it appears you go through passport control in Dublin, it's a matter of whether your flight lands on time, and how long it takes to get to your gate. If you need to catch the tram from the plane to the terminal, that will take a few minutes.

As a flyer out of Dulles, usually planes coming in overseas dock in a separate terminal from the rest of the airport. You then have to take people-movers(think 1960s ideas) to regular terminal. Until the people-movers/trams are filled, they won't move. So I'd say it will be a good half hour from when you finally deplane and get to terminal than find your gate. Since you are booked all the way on United even if you did miss your flight they'd have to find a way home for you. Also planes can frequently be delayed by thunderstorms going cross country. It's dicey but if worse comes to worse, United will still have to get you home.

As a flyer out of Dulles, usually planes coming in overseas dock in a separate terminal from the rest of the airport.

As noted, Kim won’t have this issue as she will go through immigration in Dublin.

There are two immIgration areas at Dulles. If you are arriving on a United flight and connecting, you go through immigration in the United midfield terminal. If Dulles is your final destination or if you are flying on an airline other than United then you get on the mobile lounge and are transported to the international arrivals area in the main terminal.

Just be sure you plan on arriving in Dublin’s airport earlier to clear customs. We arrived about 2 hours and 45 minutes before our flight. Going through customs took a little while, but it was great to have it out of the way before landing in the states. We just got back a month ago! It was such a wonderful, peaceful vacation. Have fun!