U.S. News: Early decision applications typically require the signature of the student, parent and counselor verifying the commitment. The agreement is not legally binding, so a college would not go after a student for tuition. But depending on the school, there can be consequences if a student doesn't accept an offer.
For example, if it is discovered that a student applied early decision to two different colleges – breaking the agreement – a student risks losing both acceptances. There are exceptions, however. Some families may receive a financial aid package that's different than anticipated, making it difficult to afford the cost of attendance. At Duke, fewer than 1% of early decision applicants admitted aren't able to enroll for financial reasons.
Admissions officers understand if extenuating circumstances prevent a student from honoring their commitment, including an illness or death in the family that leads a student to defer enrolling for a semester or year, experts say. If that's the case, they advise students to reach out to the institution as soon as possible.