Iowa Code § 321H.5

A license issued under the provisions of this chapter shall specify the location of the principal place of business, the location of each extension within the county of the principal place of business, and for licenses issued on or after January 1, 2016, the licensee’s registration number for the national motor vehicle title information system. The license shall be conspicuously displayed at the principal place of business except during periods when the license is surrendered for modifications.