Iowa Code § 97C.11: Payment — adjustment or refund.

Taxes deducted by the employer from the earnings of employees or upon the employers shall be paid in a manner, at times and under conditions prescribed by the state agency. If more or less than the correct amount of the tax imposed upon the employer is paid or deducted, proper adjustments or refund, if adjustment is impracticable, shall be made in a manner and at times as the state agency prescribes.