Arizona Rent Late Fee Rules

Under A.R.S. § 33-1368(B), a landlord may impose a 'reasonable late fee set forth in a written rental agreement,' but the fee must be written into the lease to be enforceable. Arizona sets no specific dollar amount or percentage and provides no mandatory grace period, so rent is due on the date in the lease and a fee may apply the next day unless the agreement says otherwise. Because the standard is reasonableness, a fee that functions as a penalty rather than an estimate of the landlord's actual loss may be challenged. The same statute governs nonpayment: the landlord must serve a 5-day notice before terminating for unpaid rent.

No specific statutory penalty. An unreasonable or unwritten late fee is unenforceable; a tenant may contest it in court, and a landlord cannot use an invalid fee as grounds to terminate or to defeat reinstatement after paying past-due rent.