It depends on where you’re coming from: If it’s outside the EU, then London (Heathrow) is your entry point and you will have to go thru Immigration and have your U.S. Passport stamped.

This would indicate to me that you will also have to clear British Customs.

I am implying this; I have no status with Heathrow or British Customs.

Unlike the US, Europe (including UK, Ireland, and Schengen borders) generally—i.e. as far as I know based on numerous experiences—does customs at your ultimate destination.

If your baggage gets checked all the way through to DUB at your initial check in, then you would only be transiting Heathrow, and would not fetch it until you arrive DUB.

If however your initial check-in can not tag your baggage all the way through, then you’ll have to fetch it at Heathrow, and ask at the Transit desk if you can re-check it to Dublin without going through Customs at Heathrow. (I’ve done this at Manchester most recently). If your fare breakdown lists a Customs fee for Ireland, then that would further confirm this, but tickets don’t always break down the various taxes and fees they must collect.

I thought this had changed. The last two times I flew to Europe, I went through passport check/stamp in Amsterdam even though the luggage was checked to Helsinki in one case and Vienna in the other. I also had to go through security/carry-on screening before boarding the connecting flight. That didn’t make much sense as there was no opportunity to pick up any dangerous stuff during the process. I don’t know if my checked luggage was re-screened or not as there was no “pick up your luggage and go through customs” like there is when arriving in the US.

Customs and Passport control are separate in most cases. Customs is when you pick up your luggage, declare anything that’s supposed to be taxed (or not allowed), then exit the airport (if that’s your destination) or drop it off if it’s already tagged through to your ultimate destination.

Although Schengen border streamlines travel in/out, each participating country can reinstate it’s own, more stringent, controls.

I was just through Schiphol last week and was a little surprised that security scanning did not occur until I was at the gate. (I thought maybe I had somehow bypassed it — having been through this airport probably 20 times in the past 7 years, it didn’t use to be this way). This might just be a Schiphol thing, however, and would explain you having to go through security again there.

Schiphol also has a passport check before entering each concourse. They specifically looked for my previous entry stamp, and when couldn’t find it, had to just ask me when I last entered the Netherlands. (I’m glad they didn’t ask when I had last entered Schengen, because I technically had overstayed ).

This was the case for me in 2008, returning from Helsinki. Not only did they do the basic screening at the gate, they brought in a team of about a dozen folks and set up several podiums to do fairly detailed interviews of every passenger. I was asked to name every country I’d visited and for a detailed description of my travel so far that day including which hotel I’d stayed at in Helsinki and how I got to the airport, plus a couple of questions about my very basic cell phone. This in addition to the usual did you pack your own bag and has it been in your possession since you packed it questions. I assumed it was heightened security due to a specific threat.

Thanks everyone! Appreciate the responses. I think realistically there’s no way I’m going to be able to carry on my bag, so I’ll have to check it. I’ll stick with a 2 hour gap to keep things extra safe.

Anyone know if they eyeball you funny when you come in on a one way ticket? I’ve got a return, it’s just not on the same ticket. Wondering if I should expect to add another hour or two for when they take me to the scary secret room for questioning.