A.R.S. § 43-505: Tax payments made to department; order of crediting

A. The tax and any interest and penalties shall be paid to the department. Remittances may be in the form of a check payable to the department during such time and under such regulations as the director may prescribe. If a check is not paid by the bank on which it is drawn, the taxpayer tendering the check shall remain liable for the payment of the tax and all interest and penalties as if he had not tendered the check.

B. The department shall credit payments against a taxpayer's unpaid tax liability before crediting payments against any interest or penalties.