How long for is the ESTA valid?
2 years. In the case of revocation or expiration, the ESTA is no longer valid. If the ESTA expires while you are in the United States, it is not necessary to request a new one since the document must be valid at the time of entry into the United States.
Giles has obtained his travel document 9 months ago while traveling with his family to Orlando for his daughter Olivia’s birthday. In two months Giles will go Denver, Colorado for 5 days for an important business meeting. Since his Esta is valid for two years (provided that the passport he associated is still the same) in order to go to Denver he can use the same authorization he used 9 months ago to travel to Orlando with his family.
In January of this year, Valeria thanks to the Esta attended an English course in New York (less than 21 hours a week, otherwise she should have had to get a student visa). She was 88 days total in the USA.
In May thanks to her travel authorization Valeria returned to New York to attend one of her dearest friend’s wedding, which she met exactly during her English course in January. She spent 3 more weeks in the Big Apple.
Valeria spent 109 days altogether on the American territory in the solar year.
Today Valeria was planning a car trip to the discovery of the United States, which would have lasted 3 more months but this time she will need to apply for a type B visa.
The Esta, in fact, allows for multiple entrances in the USA but the total sum of visits cannot exceed 180 days in the solar year. And the maximum duration of each visit cannot be longer than 90 days.