A.R.S. § 44-1202: Forfeiture of all interest upon obligation involving interest exceeding the maximum amount set by contract

A person shall not directly or indirectly take or receive in money, goods or things in action, or in any other way, any greater sum or any greater value for the loan or forbearance of any money, goods or things in action, than the maximum permitted by law. Any person, contracting for, reserving or receiving, directly or indirectly, any greater sum of value shall, forfeit all interest.