Due to sanctions, none of the international credit/debit cards are practical in Iran. The Iranian banking system is local and offers Shetab credit cards which only works in Iran. You can use these credit cards in ATMs all over Iran, including shopping in stores, and other payments. The currency in Iran is Rial (official) and Toman which is more common among the people. Upon request, Medova will provide you a credit card from one of the Iranian banks with financial credit as much as you want and then you can easily use it wherever inside Iran.