Iowa Code § 321.98: Operation without registration.

1. Except as otherwise expressly permitted in this chapter, a person shall not operate and an owner shall not knowingly permit to be operated upon any highway any vehicle required to be registered and titled under this chapter unless:

a. A valid registration card and registration plate or plates issued for the vehicle for the current registration year are attached to and displayed on the vehicle when and as required by this chapter; and

b. A certificate of title has been issued for the vehicle.

2. Any violation of this section is a simple misdemeanor punishable as a scheduled violation under section 805.8A, subsection 2.