The Visa Waiver Program (VWP) allows citizens of participating countries to travel to the United States for tourism or business purposes without obtaining a visa. Instead, travelers must apply for an Electronic System for Travel Authorization (ESTA) prior to their trip. The VWP allows visits of up to 90 days.
In most cases, an ESTA will be valid for two years. However, travelers must obtain a new ESTA if they: (1) receive a new passport, including an emergency or temporary passport; (2) change their name; (3) change their gender; (4) change their country of citizenship; or (5) need to change responses to any of the “yes” or “no” questions on the ESTA application.