Do I need an ESTA if I am only connecting through a US airport?
The short answer
Yes, if you are from a Visa Waiver Program country. CBP says VWP travellers in transit require either an ESTA or a visa. Travellers from other countries need a visa rather than an ESTA.
What CBP says
CBP's Visa Waiver Program and ESTA frequently asked questions say VWP travellers in transit through the United States require either an ESTA or a visa. A short connection does not remove the requirement.
If you are only in transit, CBP says to enter "In Transit" and your final destination under the address field, Address While In The United States.
UK and EU travellers
The CBP page speaks of VWP travellers in general. Whether UK or EU citizens qualify depends on the VWP country list, which you should check on the official CBP site. Citizens of countries outside the Visa Waiver Program need a visa instead of an ESTA.
US citizens do not apply for an ESTA, and the CBP page read is aimed at foreign travellers.
Validity and applying
CBP says ESTA approvals are typically granted for a two year period or until the applicant's passport expires, whichever is sooner. It advises applying at any time, but preferably as soon as you begin to plan a trip. The FAQ page read does not state the current fee, so check the official ESTA site for the fee before you apply.
Practical points
Apply only through the official government ESTA website. Rules, fees and processing change, so check the official CBP pages before you fly. See our other guides for the current fee and the Visa Waiver Program.
Sources: CBP: Frequently Asked Questions about the Visa Waiver Program (VWP) and ESTA. Read 5 November 2026. Rules and fees change, so check the official page before you travel.
Frequently asked questions
Do I need an ESTA if I never leave the airport?
CBP says VWP travellers in transit require either an ESTA or a visa. The page does not make an exception for staying airside.
What do I enter for address when transiting?
CBP says to enter In Transit and your final destination under Address While In The United States.
How long does an ESTA last?
CBP says typically two years or until your passport expires, whichever is sooner.
What if my country is not in the Visa Waiver Program?
You would need a visa. The ESTA is only for VWP travellers.
How much does an ESTA cost?
The CBP FAQ page read does not state a dollar amount. Check the official ESTA website.
When should I apply?
CBP says at any time, but preferably as soon as you start planning your trip.