We are flying in to Heathrow and then catching a flight to Dublin (cheaper to fly in to London and take a cheap flight to Dublin instead of to Dublin based on where we are traveling from). So this is not a connecting flight but rather a separate one. I believe we will have to exit through customs/immigration and then reenter the secured airport area to go back in for our next flight. Is anyone able to confirm this? Also, will we have to go through customs when we arrive in Dublin.
Yes, you will go through Immigration, customs and security at Heathrow.
If you are traveling with a US or Canadian passport, you will also go through immigration/passport control and customs in Dublin.
Go to this website, fill in the requested information, and you will get step by step instructions for connecting at Heathrow:
Last week we flew Denver to Heathrow, then a cheap flight from Heathrow to Cork (not Dublin). So those are some differences, but assuming the Irish procedures are consistent:
At Heathrow, we landed at Terminal 5, but had to transfer to Terminal 2 for our onward flight to Ireland. Upon reaching Terminal 2 we went through Security (liquids displayed in a 1-liter baggie, belts off but shoes on) and a Passport check. There was no Customs experience.
Upon reaching Ireland, we had Immigration (long, slow line for Passport inspection with a nasty American cutting in line!), then past the baggage carousels a very long line for Customs. Even doing carryon only, we went to the end of the line, behind people who’d just gotten their bags. Most people filed slowly past one uniformed customs official who stared at everyone who went by, but nothing was said or formally checked. There was a couple having to put their bags through a scanner and being subjected to some involved discussion, but we didn’t stick around to see what that all involved.
Thank you BOTH so much. I really appreciate having this information.