Iowa Code § 8A.507

If an officer who is accountable to the state treasury for any money or property neglects to render an account to the director within the time prescribed by law, or if no time is so prescribed, within twenty days after being required to do so by the director, the director shall state an account against the officer from the books of the officer’s office, charging ten percent damages on the whole sum appearing due, and interest at the rate of six percent per annum on the aggregate from the time when the account should have been rendered; all of which may be recovered by action brought on the account, or on the official bond of the officer.