Ariz. Rev. Stat. § 42-19051 – Administrative review of valuation or classification by assessor

A. The owner of property that is valued by the assessor or the person in whose possession it is found may appeal to the assessor within thirty days after the date the notice was delivered by filing a petition with the assessor on a form prescribed by the department. The petition shall set forth in writing:
1. 1. The owner's opinion of the value or legal classification of the property.
2. 2. Substantial information that justifies the opinion of value or legal classification in order for the assessor to consider the information for the purpose of basing a change in the valuation or legal classification.
B. The assessor shall rule on each petition within twenty days after it is filed.
C. The notice provided under this section shall be in the same manner as prescribed in section 42-16056.
D. If the request of the petitioner is denied, in whole or in part, the assessor shall deliver to the petitioner written notice of the grounds for refusing to grant the request contained in the petition.