What should I know about the currency & exchange?

The official currency is called Iranian Rials (IRR). You will often hear the term ‘Tomans’ used on the street, which is simply equal to 10 Rials.
As a general rule of thumb, written prices are given in Rials and in conversation, Tomans. Due to U.S. led sanctions foreign banks are restricted from engaging directly in Iran; so forget Cirrus, Maesto, Visa, Marstercard, Paypal, and travellers cheques because these are almost impossible to find without local connection. So ensure you bring enough cash while travelling in Iran.While ATM’s are generally only for Iranian customers, some banks and hotels may be able to help you transfer foreign currency electronically, but don’t be afraid to ask tourist agencies for assistance as they can be very resourceful.
US dollars and Euros are the most useful and widely-accepted currencies.