I'm a US citizen that traveled to the UK a long time ago and was detained and sent back right away because I didn't have a round trip ticket, I had no travel insurance, and low funds in my account. They stamped my passport with a stamp that has a horizontal line, then a vertical line overlaying the middle of the horizontal. They gave me a ton of paper work listing the reasons why I got sent back.
Six months later I tried flying to Dublin, Ireland. This time traveling I came more than prepared. I went there with the papers the Heathrow airport gave me, travel insurance, a round trip ticket, and proof of funds. But they saw that stamp in my passport and from then on I was sent to the detained section of the airport while they looked over everything. After about an hour they came back and they said they will allow me to stay. But they said I MUST leave on the date I said I will, and I can't fly out to the UK from there or I will be banned from Ireland and the UK. I had to send them proof of me leaving on the date I said I would and that was that.
My question is, will this be a reoccurring issue wherever I travel to or is this something that I'll only have an issue with the UK and Ireland? I'm planning on traveling from Washington DC on a non-stop flight to Dubai and I'm kind of nervous to fly 13 hours to be sent straight back on another 13 hour flight.
I'm going to be bringing proof of everything when I go. Proof of insurance, finances, round trip tickets, accommodation. I just wanted to see what you all had any knowledge on this topic. I appreciate any help. Thank you!