Iowa Code § 325A.8: Required marking.

1. The motor carrier shall attach distinctive markings or tags to each motor vehicle. If a motor vehicle has both an interstate and intrastate motor carrier number, only the interstate motor carrier number must be displayed.

2. If a motor carrier is renting a vehicle on a daily basis, a copy of the lease must be carried in the vehicle. Violation of this section is a scheduled violation subject to the fine provided in section 805.8A, subsection 13, paragraph “d”.