Penalty for short-levy or non-levy of customs duty equals the duty or interest when collusion or willful suppression is found. A new provision imposes a penalty equal to the duty or interest determined to be payable where duty or interest has been short-levied, not levied, or erroneously refunded by reason of collusion, willful misstatement, or suppression of facts; the person determined liable for duty or interest under the assessment mechanism is liable for the penalty, and appellate adjustments to duty or interest are reflected in the penalty calculation, while imposition of this penalty precludes levying alternate penalties for the same default.