Iowa Code § 8A.503
The director shall prescribe by rule the manner and methods by which all departments and agencies of the state who collect money for and on behalf of the state shall cause the money to be deposited with the treasurer of state or in a depository designated by the treasurer of state. All such moneys collected shall be deposited at such times and in such depositories to permit the state of Iowa to deposit the funds in a manner consistent with the state's investment policies. All such moneys shall be promptly deposited, as directed, even though the individual amount remitted may not be correct. If any individual amount remitted is in excess of the amount required, the department or agency receiving the same shall refund the excess amount. If the individual amount remitted is insufficient, the person, firm, or corporation concerned shall be immediately billed for the amount of the deficiency.
Iowa Code § 8A.503
2003 Acts, ch 145, § 85