The rial is the official currency of the Islamic Republic of Iran. The decimalised version of this currency was introduced in 1932. The rial is subdivided into 100 dinar, but the dinar exists only for accounting purposes and electronic transactions. In addition, many Iranians use an unofficial unit of currency called the toman, with one toman equal to 10 rials. Talks to redenominate the currency of Iran due to inflation have been ongoing since the 1980s, but a plan has yet to be executed. The symbol used for the Iranian rial is not officially approved by the government or the Central Bank of the Islamic Republic of Iran, but is a creation of the Institute of Standards and Industrial Research of Iran (ISIRI).
The first rial was introduced in Iran in 1798 as a coin valued at 1250 dinar, or one-eighth toman. In 1825, the rial was replaced by the qiran, equal to 1000 dinars, in order to decimalise the currency. After over 100 years, a stronger effort was made to establish a modern decimal currency in Iran, and the rial was reissued in 1932, this time as the primary currency unit with the dinar as a hundredth subunit. The original value of the new rial was 59.75 rial: 1 pound sterling. Throughout the 1930s and ’40s, the rial fell in value until it was pegged to the U.S. dollar in 1945 at a rate of 32.25 rial: 1 USD. The peg was redefined twice until it was dropped altogether in 1975. In the 1980s, after the Islamic revolution, the value of the rial dropped significantly due to capital flight of more than A$36 billion. In 1978, 1 AUD exchanged for around 80 IRR, but by 1999, 1 AUD exchanged for 11,000 IRR.
Although the Iranian rial had partially recovered in value, it has recently fallen again due to economic and travel restrictions imposed in 2010 by the United Nations. Foreign currency exchange in Iran is facilitated by the government, the central bank of Iran and a network of 50 Iranian forex dealers located in the Middle East and Europe. The value of the rial is set through a trading system on the Tehran Stock Exchange, so the market rate is often referred to as the TSE rate. In 2010, an economic reform plan was announced to redenominate the rial at rate of 1000: 1, but in 2011, a new plan was revealed to redenominate at 10,000: 1.