About the US Travel Authorization System Only passport holders from a visa waiver country can apply for a US travel authorization, which is now mandatory in order to enter the US via air or sea. The application process is done online, and the application can be done by yourself or through a third party. Once approved your travel authorization will be linked to your passport, so when you check in at the airport - the agent will see that you are approved to travel to the United States.   Every traveler under the visa waiver program must have his or her own approved travel authorization. There are no "family applications". Children and infants must each have their own passport and own approved travel authorization. The validity of an authorization is normally two years unless your passport expires earlier. Travelers in transit must also obtain an approved travel authorization in advance. You can apply at any time as no particular travel plans are required. ESTA is short for the "Electronic System for Travel Authorization". The system is an online application system developed by the United States government to pre-screen travelers before they are allow to board an airplane or ship bound for the United States. The ESTA process is very similar to the ETA process that the Australian government has been operating for many years. All travelers entering the United States (by air or sea) under the visa waiver program are required to hold a valid US travel authorization. The purpose of ESTA is to allow DHS to pre-screen all Visa Waiver Travelers before they leave their respective countries. U.S.-bound travelers are recommended to apply for a Travel Authorization at least 72 hours prior to departure. The visa waiver program is a U.S. government program that enables citizens and nationals from the Visa Waiver Countries to enter the United States for tourism or business purposes for up to 90 days without obtaining a US tourist visa. The visa waiver program is constantly being expanded to include new countries that qualify. Disclaimer: This is an information website written by a private company. This website is created for informational purposes only and does not provide legal advice.