Is it permissible to change money on the black market?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is permissible for you to exchange your currency from any place whether it is a bank or an individual who pays you a higher price provided the transaction should be hand to hand between two parties (i.e. the seller and the buyer of the currency) and at the same place where the sale contract is carried out.
Since any delay in this transaction is forbidden and it is called (Riba al-Naseea). The Prophet said: "But if these (the six kinds mentioned in the Hadith) are different, trade as you wish but from hand to hand." [Muslim]
However, if any government prohibited exchanging money except through the official banks and this prohibition is based upon a valid reason in the Sharee’ah, then you should exchange only from the official sources. Because a government can limit some lawful ways though there are many other lawful ways to protect the national interest. However, if the prohibition of a government is not for any valid reason in the Sharee’ah, then it is permissible for you to exchange anywhere taking into consideration the above condition.
Allah knows best.
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