If you're wondering How to Apply for ESTA, the process is simple for eligible travelers. Complete the online application with your personal information, passport details, travel plans, and security-related questions. Carefully review all information before submitting the form and paying the required application fee. After submission, your application will be reviewed by U.S. authorities. Once approved, your ESTA is electronically connected to your passport and should be valid when you board your flight to the United States.