The ESTA or Electronic System for Travel Authorization is an automated system that grants eligible travelers permission to enter the United States of America without a visa.
Individuals from the Visa Waiver countries can complete an ESTA application form online in order to obtain this travel authorization.
The system is used by the Government of the United States of America to determine the eligibility status of citizens from selected countries to travel to the US under the Visa Waiver Program, without having to previously apply for a USA visa.
One of the ESTA requirements is a valid passport issued by one of these approved sovereign states.
Starting on January 12, 2009, all individuals planning to enter the country under this program must be holders of a valid ESTA visa waiver for the USA.
The processing time for an ESTA visa waiver is up to 72 hours, which means candidates can make their online application prior to boarding the plane.
The ESTA for America is not a visa, and therefore valid US visa holders do not need to apply for the travel authorization, as an ESTA and a visa cannot be granted simultaneously. ESTA holders will not be required to fill in the Green I-94 Card upon their arrival in the US. However, travelers will need to fill in a blue customs declaration, whether they are ESTA holders or not.
ESTA USA has a validity period of 2 consecutive years (or until the traveler’s passport expires). During this time, successful applicants may travel multiple times to the US for short periods of time (up to 90 days per stay).
Take note that an overstay (over 90 days) can lead to Customs and Border Protection (CBP) making the individual’s ESTA ineligible for future entries and this could also affect future applications.
It is recommended to travel to the US in reasonable intervals of time and not to abuse the rights given to US ESTA holders. Traveling back and forth for long periods of time might cause the border officials to believe you are intending to live there.