The Iranian currency is Rial, the currency code for Rial is IRR, and the symbol of it is ریال.
All foreign currencies such as Euro, pound, sterling, Us dollar are changeable in Iran, ATMS in Iran don’t accept international credit cards, as a result the best way is to pay by cash.(except for some shopkeepers.)
Note: Although the official currency in Iran is Rial, Iranians tend to use Toman instead in their daily payments. So, it’s better to get familiar with them in advance in order not to be confused. For example, by eliminating one zero of 10000 Rials, it will be changed to 1000 Tomans.