Iowa Admin. Code r. 701-101.11
The director or the director's authorized representative shall have the right to examine or cause to be examined the books, papers, records, memoranda or documents of a taxpayer for the purpose of verifying the correctness of a tax return filed, of information presented, or for estimating the tax liability of a taxpayer. When a taxpayer fails or refuses to produce the records for examination upon request, the director shall have authority to require, by a subpoena, the attendance of the taxpayer and any other witness(es) whom the director deems necessary or expedient to examine and compel the taxpayer and witness(es) to produce books, papers, records, memoranda or documents relating in any manner to the replacement tax.
Iowa Admin. Code r. 701-101.11