Decisions on whether the ETIAS will be granted are made on a case-by-case basis. As ETIAS is in place to prevent terrorism and serious crime in Europe, only those individuals deemed a threat will go on to have their request denied. Travelers with minor convictions should not be deterred from applying for ETIAS.

ETIAS (European Travel Information and Authorisation System) applications can be denied for several reasons, primarily focused on security, health, and illegal immigration risks. An applicant will be denied if their travel document is reported as lost, stolen, or invalidated in the SIS (Schengen Information System). Security grounds are the most common; those with criminal records for serious offenses like terrorism, human trafficking, or drug trafficking, or those appearing on security watchlists, will likely face refusal. Additionally, applicants who provide false information or fail to attend a requested interview (in rare cases) will be rejected. Health-wise, those carrying high-epidemic-risk diseases may be flagged. Finally, if the system determines there is a high risk of the applicant overstaying their 90-day limit or if they have previously been deported from an EU country, the authorization will be denied. Most denials are issued within 96 hours, though users have the right to appeal the decision through the specific member state that issued the refusal.