[2] After approval, the authorization remains valid for two years, or until the passport expires if earlier, for multiple trips during that period.

On September 8, 2010, following the Travel Promotion Act, CBP began charging a fee of $4 to cover administrative costs, and if the application was approved, an additional fee of $10 to fund the Corporation for Travel Promotion (also known as Brand USA[9]), for a total of $14 for each approved ESTA.

Due to the Visa Waiver Program Improvement and Terrorist Travel Prevention Act of 2015, those who have been in Iran, Iraq, Libya, North Korea, Somalia, Sudan, Syria or Yemen on or after March 1, 2011, or in Cuba on or after January 12, 2021, or who are dual nationals of Cuba, Iran, Iraq, North Korea, Sudan or Syria, are not eligible to travel under the VWP.

[17] However, those who traveled to such countries for diplomatic, military, humanitarian, reporting or legitimate business purposes may have this ineligibility waived by the Secretary of Homeland Security.

[3] Each entry under the Visa Waiver Program is only valid for a combined maximum stay of 90 days in the United States and its surrounding countries.

CBP officers make the final determination of admissibility (entry) to the United States and may cancel or deny ESTA at any time during travel, for example for suspicions of giving false information in the application.

[34] Third-party websites try to make themselves look legitimate by using official-sounding web addresses and posting logos that resemble the U.S. government emblem.

[35] Concerns have been raised that third-party sites could be used for identity theft, credit card fraud, or the distribution of malware.