SHAFAQNA – The Grand Ayatollah Khamenei answered a question about buying and selling bank notes for higher prices.
Question: What is the ruling for buying and selling bank notes on credit for higher prices?
The Grand Ayatollah Khamenei: There is no problem if the above-mentioned deal is with the intention of being bone fide and rational, for example; the notes differ from each other by being old and new, or they have special signs, or their prices are different from each other. But if the deal is fictitious (fake) and (it is only) for the sake of escaping usury, and in reality it is for earning profit (interest) from the money, according to religious laws it is Haram and void.
Source: PERSIAN SHAFAQNA