not sufficient funds (NSF)

Reason for dishonoring or returning a check to its depositor, because the amount available in check-writer's (drawer's) account is less than the check's amount. Usually both the depositor and the drawer of the returned check have to pay a penalty to their respective banks. If a drawer's checks are returned frequently, his or her bank may unilaterally close that account. In some jurisdictions it is a criminal offense to knowingly issue a check that will be returned. Sometimes the words 'no funds' or 'refer to drawer' are instead used.