The United States is making some changes to the way it lets people into the country, and it’s bound to cause a few headaches. All travelers entering the US (by air or sea) under the visa waiver program are required to hold a valid ESTA travel authorization, but the Department of Homeland Security is making the process of getting one more complicated. The ESTA gives visitors the ability to travel to the US for up to 90 days, and is valid for up to two years across multiple trips. Real-time approvals of the ESTA, however, are no longer available, meaning passengers must apply for the ESTA no later than 72 hours before their departure for the US.

Previously, ESTAs were granted almost immediately, even to those who showed up at the airport without a permit. Now, according to the DHS, “Real-time approvals will no longer be available and arriving at the airport without a previously approved ESTA will likely result in being denied boarding.” Prospective entrants will be inspected by a Customs and Border Protection officer at the airport, and a decision will be made on the spot regarding their admission.

H/T: Lonely Planet