The banknote stands in the place of the rupee
Question
Question: How is the Shar‘i requirement of a valid sale to be observed in the present age, when purchases are made with banknotes, with which silver and gold are also bought; the purchase does not take place at one time and in one place; the price is paid as a debt by cheque, or it is also done by V.P. (value-payable post)? In this situation the conditions of a Shar‘i sale are not fulfilled, otherwise the one who does it remains sinful.
Answer
Now that the rupee has become very scarce — as if it has become rare — the banknote itself has been treated as standing in the place of the rupee, since all business is now conducted with banknotes. If the banknote were to keep its original status (that of a transfer — hawala), the general public would fall into great hardship.
Source: Fatawa Mahmudiyya
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