Ariz. Rev. Stat. § 44-6002
C. A retail installment contract which otherwise conforms to the requirements of this chapter may contain provisions which relate to additional goods and services authorizing any of the following:
D. Under a retail charge account agreement a rate of finance charge not to exceed the maximum rate set by contract may be charged and received on an amount not in excess of the greatest of any of the following:
J. In this section: