Ariz. Rev. Stat. § 44-1366
A. Unless otherwise prohibited by law, a seller of consumer services may impose a delinquency fee on any consumer with an account that has an unpaid balance of more than ten dollars if the following conditions are met:
B. In any consumer service transaction the seller may impose a collection fee that is not more than ten dollars and that is in addition to the delinquency fee prescribed in subsection A if the seller does both of the following:
C. This article does not: