UK Electronic Travel Authorization (ETA) — For Connections Through the UK

If any leg of your flight routes through the United Kingdom — even just a layover at Heathrow or Gatwick on the way to your destination — you’ll need a UK Electronic Travel Authorization (ETA) before you fly. This is a relatively new requirement, and it catches a lot of U.S. travelers off guard, so check your itinerary now.

Who needs one

As of January 8, 2025, all visa-exempt travelers with non-European passports — including U.S. citizens — need a UK ETA to enter or transit through the United Kingdom. If your flight connects through London (or any other UK airport), you need one even if you never leave the airport.

If your flights skip the UK entirely — for example, a direct route from the U.S. to Lisbon, or a connection through Madrid, Paris, or Frankfurt — you don’t need a UK ETA.

The basics

• Cost: £20 (about $27 USD), paid by credit or debit card.
• Processing time: up to 72 hours. Apply well in advance — don’t leave this for the day before you fly.
• Validity: linked digitally to your passport. Once it’s approved, there’s no paperwork to print or carry. Just keep the approval email handy in case anyone asks at check-in.

How to apply

The easiest path is the official UK ETA app — it’s free in both the Apple App Store and on Google Play. You can also apply online at the official UK government site: gov.uk/apply-for-an-electronic-travel-authorisation-eta.

You’ll need:

• Your passport.
• A digital photo of yourself (the app walks you through it).
• Basic personal details and answers to a few security questions.
• A credit or debit card for the £20 fee.

The whole application takes about 10 minutes. Most approvals come back within a few hours, but the government officially allows up to 72 hours — so don’t apply at the airport.

Once you’re approved

Your ETA is linked electronically to your passport — nothing to print, nothing to stamp. It’s valid for multiple visits over two years (or until your passport expires, whichever comes first), so once you have one, future UK transits are covered.

Save the approval email on your phone just in case an airline agent asks for it at check-in. Rare, but it happens.

A quick heads-up

If you’re booking through your own travel agent or building your own flights, double-check your routing now. UK connections are common on transatlantic itineraries and it’s easy to miss the ETA requirement until you’re at the gate and the airline won’t let you board. Five minutes of attention today saves a very bad day at the airport.