UK ETA -- Lost response eMail? How to validate # prior to travel?

Use whatever she got as approval. Did you all use the gov.uk app or website?

As long as you have received confirmation that your ETA has been approved, you don't need to take anything with you. The ETA will have been linked to your passport and airport check-in staff will see it when you leave home.

I have entered the UK twice since the ETA was required. No problems. Same as before.

As long as you have your confirmation numbers you are fine. If there is a problem, you will know when you try to check in for your flight.

Yes, the ETA is linked to your passport. No, the airport staff cannot see this.

When you check in online, you give your passport details. This is shared with the UK Border Force and if there is a problem, they will inform the airline not to allow you on the flight until the problem is fixed. You will be alerted.

When you check in at the check in counter, they enter your passport information into the computer and it is sent to Border Force for approval. It just takes a few seconds.

At the gate, when they ask to see your passport, they are just checking to make sure you have your passport and it is yours. They are not checking for ETA's.

By the way, the same thing is done when you fly back to the US. Your passport, and Trusted Traveler information if you have this, is sent to Homeland Security. That's why, at times, your boarding pass out of the UK back to the US will say "TSA Precheck" even though there is no precheck in the UK.

Frank,

Your explanation is very detailed and helpful. Not sure what happened to the following traveler but it's what prompted me to start this inquiry.

https://community.ricksteves.com/travel-forum/trip-reports/my-uk-eta-unexpected-experience-yesterday-flying-from-sicily-to-uk

Best regards,
Scott

That incident happened because the gate agent didn't understand what the ETA was.

If you get someone like that, just show them the email. If they still want more, ask for a supervisor.

I remember a friend tellling me he almost didn't make his flight from NY to San Juan, Puerto Rico because the airline gate agent insisted that it was an international flight and passengers needed a passport. She was insistent. But, after quite a few passengers didn't have passports, she called a supervisor who cleared things up.

Many years ago before computer printed baggage tags, I was taking a chartered flight to Guymas, Mexico. The airport code is GYM. I noticed while checking in, they were putting on baggage tags that said GUM--Guam. I pointed this out to the check in folks and they freaked out because I was near the end of the line. (The airline had regular service to Guam.) Fortunately, all the bags were rounded up and the proper tags were put on.

I've traveled to the UK twice since January and noone asked to see the ETA email (indeed the email specifically says you don't need to show it). As Frank says, the Advance Passenger Information the airline submits returns an automated response to the airline on your ETA status - no need to show anything.