Ariz. Admin. Code § R15-5-171
Gross receipts from sales made to a common carrier, engaged in interstate business, for delivery by the common carrier to a location outside of Arizona and for use outside of Arizona shall not be taxable if the order is received from a location outside of Arizona and the Arizona retailer prepays the freight charge.
Adopted effective August 9, 1993 (Supp. 93-3).