The Iranian Central Bank has set a $5,000 limit on the amount of foreign currency travelers can enter or exit the country, the Iranian Labour News Agency (IRNA) reports.
Those travelers who want to bring or take more than $5,000 with them have to complete a foreign currency declaration at the entry or exit point to Iran.
Iran's foreign currency market has become increasingly chaotic over recent days. The government officially launched the Iran Forex Centre on September 24 in an effort to stop the national currency's (the rial) plunge in value but that move hasn't been effective.
Since the center opened last week a dollar has gone from costing 25,500 rials to 36,200 rials by yesterday (Tuesday) afternoon.
But Iran's economy is under increasing pressure because of international sanctions that have made it extremely difficult for Iran to sell its oil and have access to its foreign currency holdings around the world.
Earlier today, Economy Minister Seyed Shamseddin Hosseini said the government has plenty of foreign currency and there is no need to ration it.