For travel to the United States, passengers from countries that do not need to apply for a visa, as is the case in Spain, since last year we had the option before traveling to fill in the so-called ESTA form, after which we are granted a prior authorization that facilitates the procedures of passing through customs.
As of March 20 of this year 2010, it becomes mandatory to complete said ESTA form, which we must do exclusively by Internet, As minimum 72 hours before of our trip to the United States.
The normal thing is that we immediately respond with a prior authorization, which we must print and carry with the passport. This step does not ensure a definitive authorization to enter the United States, which is only given at the same customs.
The filling in the ESTA Form To travel to the United States is carried out exclusively through the website of the United States Department of Customs Security, and is completely free.
Therefore, although some websites have established a system to fill it in your name charging a fee, it is a very simple procedure that you can do directly without any charge.
In GUIDES TRAVEL TO THE UNITED STATES you have all the necessary information to complete the ESTA Form before you trip to the United States.