Ariz. Rev. Stat. § 28-2159 – Staggered registration

A. The director shall establish a system of staggered registration on a monthly basis to distribute the work of registering vehicles as uniformly as practicable throughout the twelve months of the calendar year.
B. All vehicle registrations provided in this chapter expire pursuant to schedules established by the director. The director may set the number of renewal periods within the month from one each month to one each day depending on which system is most economical and best accommodates the public.
C. If adoption of the staggered system results in the expiration of any registration more than a year from its issuance, the department shall charge a prorated registration fee in addition to the annual fee.
D. In order to initiate a system of registering or reregistering vehicles during any month of the calendar year, the director may register or reregister a vehicle for more or less than a twelve month period, but not more than eighteen months, and may prorate the annual registration fee if in the director's opinion proration tends to fulfill the purpose of the monthly registration system.
E. The director may provide for a two year or five year registration period for any vehicle not subject to annual emissions testing pursuant to section 49-542. For vehicles eligible for a two year or five year registration, the director shall provide in each renewal registration packet information that clearly indicates:
1. 1. The vehicle owner has a choice of registering the vehicle for one year, for two years or for five years.
2. 2. The total amount due for a one year registration period.
3. 3. The total amount due for a two year registration period.
4. 4. The total amount due for a five year registration period.
F. The director or a registering officer may allow a person who owns three or more vehicles to register or reregister the vehicles for less than one year so that the vehicles' registrations expire on the same date. The director may not delay the registration date for a vehicle if it causes a decrease in the vehicle license tax. The director or the registering officer shall prorate the registration fee of these vehicles. This subsection does not apply to a commercial vehicle with a gross weight of more than ten thousand pounds or to a motor vehicle rental or leasing agency.
G. The director shall adopt rules necessary to accomplish the purposes of this section.