In effect, passengers flying from – for instance – the Middle East to North America via Heathrow would have had to have acquired an ETA for that brief period where they are in transit, typically a couple of hours spent within the confines of the airport.
Earlier this month, the UK extended its ETA regime to all non-Europeans travelling to Europe without a visa. Like the US Esta or the EU Etias, which the bloc hopes to finally roll out this year pending the launch of the EU Entry-Exit System, the ETA is a visa waiver.
