As of February 25, 2026, the era of "passport and go" travel for U.S. citizens visiting the United Kingdom has officially ended. All U.S. citizens traveling to the UK for tourism, business, or short-term study (under 6 months) are now required to obtain an Electronic Travel Authorisation (ETA) before their journey. The ETA carries a fee of £10 (approximately $13) and is a mandatory digital permit linked to the traveler's passport. It is valid for multiple entries over a two-year period, or until the passport expires, whichever comes first. This digital requirement is part of the UK Home Office's initiative to create a "fully digital border." It is a peer-to-peer essential to apply via the official UK ETA app or website at least three days before your flight; if you arrive at the airport without an approved ETA, you will likely be denied boarding by the airline, as the authorization is checked electronically during the check-in process.