Quick answer
An approved ESTA allows you to board. Admission is decided by a U.S. Customs and Border Protection officer at the port of entry. Under the Visa Waiver Program you are admitted for 90 days or less, and your arrival is recorded in an electronic I-94 record.
On this page
The I-94 record
The I-94 is the record of your arrival and departure. CBP now collects this information automatically from electronic travel records, and at land borders the I-94 is issued electronically instead of on a paper stub. You can look up your record on the CBP I-94 website or in the CBP Link mobile app.
How long you can stay
Visa Waiver Program visitors are admitted for 90 days or less. You cannot extend the stay or change to another status from inside the United States.
Trips to Canada, Mexico or nearby islands
If you leave for a short trip to Canada, Mexico or a nearby island and come back, you are generally readmitted for the remainder of the original 90 days. The total, including the side trip, must be 90 days or less.
If entry is refused
Travellers admitted under the Visa Waiver Program accept that there is no right to appeal a decision on admissibility. This is one reason some travellers prefer a visitor visa.
Sources
Checked on 13 November 2026. Rules can change; the official pages below always take priority.