UK ETA to be enforced from 25 February 2026

I don't think it's unclear. If you enter the UK and are transiting to someplace in Europe on a connecting flight, you generally won't need to go through passport control and therefore you don't need an ETA.

However if you're going outside of Europe from Heathrow or have a non-connecting ticket or have another situation that could cause you to have to go through immigration/passport control, then yes, you will need an ETA. And I'm pretty sure that's the way it was before.

Mardee - your final destination is irrelevant. If you are flying on one ticket from wherever to wherever and passing through either Heathrow or Manchester you can stay airside and will therefore not need an ETA. Use any other UK airport or fly on separate tickets or need to stay overnight in the UK and you will need an ETA. As an example many people fly from the US to Southern Africa via Heathrow - if they fly on one ticket they will not need an ETA.

Stuart’s point refers to the word “currently” - that suggests that things might change in the future.

John, I was pointing out that if you don't go through passport control at Heathrow or Manchester, then you don't need an ETA. Usually it's when you have a connecting flight from one place to another but there are exceptions. But if you don't go through passport control, then you don't need an ETA, because no one is checking your passport.

Stuart said, "It looks as if the temporary exemption to transit airside without an ETA may also be being withdrawn..."

That's what I'm talking about. I don't think it looks like it will be withdrawn, and I made my point because I didn't want to necessarily alarm other people by thinking that this is something that is going to happen. Just because it says transiting travelers do not currently need an ETA is no reason to assume that it is definitely going to change. Of course it might change in the future. There's a lot of things that could change in the future. Just about every law and regulation in place can change in the future. That doesn't mean it will. And it's a govt. press release. It's hedging its bets. 😊

If you're passing through Heathrow or Gatwick for any reason, and you're a belt and suspenders kind of traveler, just get the ETA so you have it if something comes up and you need (or want) to leave the airport and hang in the UK for a while. It's quick and relatively cheap.

Mardee - my point was that you were making a distinction between final destinations in and outside Europe when it doesn’t matter.

phred - if anyone is travelling through Gatwick they will need an ETA whatever their onward plans, as there is no airside transfer there. It’s only available in Heathrow or Manchester in the UK.

What this blog post indicates is that the ETA introductory period will come to an end on 25 Feb 2026. This has allowed people until that date to board with just an application for an ETA & people with dual nationality including British to enter on their non British passports.

There has also been a press release: https://www.gov.uk/government/news/no-permission-no-travel-uk-set-to-enforce-eta-scheme

From 25 February 2026 eligible visitors without an ETA will not be able to board their transport and cannot legally travel to the UK. ( From OP link)

My guess is that gate agents in the US won't let you board a flight to the UK, unless there is evidence of the ETA.
The verbiage implies there will be some method for the gate agents at foreign airports to discern if the passenger has a valid ETA..

Looks to me the easiest/simplest/surest thing to do is get an ETA if you are flying through a UK airport.

Arguing with a US ( or other non-UK) gate agent that "I'm transiting airside at LHR and don't need one" isn't likely to have a happy ending.