What is the ruling on currency exchange?

The questioner : The questioner says, “O honorable Shaykh, there is a transaction widespread among people, and we have heard from you that you say it is riba. The form of the transaction is that if a person wants to exchange fifty riyals in full bills for fifty in smaller denominations, he takes thirty in smaller denominations and is promised the rest after a period of time. Is this riba? We ask for clarification on this and for it to be made clear to the people? And does this include the case where a person wants to buy items and then has a remaining amount owed by the seller?”

The Shaykh : Yes, in currency exchange, the exchange of possession is obligatory in the session of the contract, due to the saying of the Prophet (peace and blessings be upon him) when he mentioned the riba currencies: So if you exchange a one-hundred bill and want to exchange it for ten-bill denominations, you must take possession of the consideration in the same session. If you take possession of some and leave some for another time, that is riba. Is it riba al-fadl or riba al-nasi'ah? If the riba is due to the delay, it is riba al-nasi'ah, and if the riba is due to the increase, it is riba al-fadl. Accordingly, the riba that occurs by delaying the full or partial taking of possession falls under the category of riba al-nasi'ah, and it is not permissible. So if you want to exchange, let the exchanger give you the entire consideration. Yes.