19 CFR 173.4a: a Refund of excess duties, fees, charges, or exaction paid prior to liquidation.

Pursuant to section 520(a)(4), Tariff Act of 1930, as amended (19 U.S.C. 1520(a)(4)), whenever an importer of record declares or it is ascertained that excess duties, fees, charges, or exactions have been deposited or paid, the Center director may, prior to liquidation of an entry or reconciliation, take appropriate action to refund the deposit or payment of excess duties, fees, charges, or exactions.