Rial and toman and their conversion is a little bit confusing. National governmental currency is Rial which most of price tags and invoices has been written in Rial on paper but verbally most of ordinary population tell the prices in toman currency. to conversion rial to toman just remove one (zero) from the right side of number and the number already changed to toman .for example if the restaurant invoice shows 370,000 toman don’t chocked just remove the last zero and the price will be 37,000 toman .
Keep in mind that change your money to rial just in valid authorized exchange centers and some banks. Don’t trust street vendors.
Most of shops and restaurants doesn’t accept foreign currencies .change your money in advance
International credit or debit cards (visa, master, pay pall,) don’t work in Iran due to political sanctions .bring cash with yourself. It’s usually not possible to change travellers’ cheques. It’s illegal to change money on the street. You should be clear before travelling how you will obtain enough rials for your visit legally, and, if unsure, you may need to reconsider your travel plans.