Iowa Code § 628.20: Excess payment — credit.

If the amount paid to the clerk is in excess of the prior bid and liens, the clerk shall refund the excess to the party paying the amount. If the clerk is the clerk of the district court where the judgment giving rise to the lien was entered, the clerk shall credit upon the lien the full amount thereof, including interest and costs, or such less amount as the lienholder is willing to credit therein, as shown by the affidavit filed.