All mandatory fields of your ESTA application must be completed. Even though CBP have not explicitly stated that leaving a mandatory field blank will result in denial, it is a highly probable consequence, since omitting any of the mandatory fields will render your ESTA application invalid.
Furthermore, such an action may require manual adjudication, which will result in slowing down your application response.
Following is a list of the most common ESTA denial reasons:
- You overstayed the maximum remain period per single trip, which is 90 consecutive days, on a previous trip.
- During the ESTA application process you used a passport number of a previously reported lost or stolen passport.
- You were denied a visa application or entry in the US
- You engaged in unauthorized activity such as work, on a previous visit to the United States.
- You gave an incorrect or a dishonest answer to one or more eligibility questions of the Visa Waiver Program.
Such eligibility questions help CBP determine whether or not you require a visa to enter the United States.
Note: Should your ESTA application be denied, you may still be able to travel to the U.S. In this case, apply for a nonimmigrant travel visa, class B1 or B2.