All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
If the transaction of exchanging currencies and selling them for each other whether between you and the company or individuals adhered to the Islamic guidelines, then there is no blame on you regarding that transaction and the profits you get from it. The most important of such guidelines is that the exchange should take place in the same meeting of concluding the contract hand-to-hand, physically or in a non-physical way, and amongst its non-physical forms is what was stated in the statement of the Islamic Fiqh Council:
“Among the non-physical forms of receiving the value that are permissible are the following:
1- Transferring money into the agent’s account in the following ways:
a. When it is deposited into the agent’s account, directly or via wire transfer.
b. When the agent makes an immediate currency exchange contract with the bank in case of buying one currency for another on behalf of the agent.
c. When the bank – on the instructions of the agent – deducts a sum of money from another account in a different currency, whether it is in the same bank or another bank, to the benefit of the agent or another beneficiary. The banks should pay attention to ensuring that they act in accordance with the principles of Islamic exchange. The delay in transferring the money before the beneficiary is actually able to take possession of it may be overlooked for the usual amount of time that such transfers take in the banking system, but it is not permissible for the beneficiary to dispose of the currency during this grace period, until the bank transaction takes effect in the sense that it becomes possible to actually receive that sum of money. [End quote]
Also, it is stipulated when selling currency for the same currency to be of equal amounts along with what we have stated that the exchange must take place in the same meeting (i.e. being hand to hand). However, if the currencies are different such as selling a Dollar for Rupee, then it is only stipulated that the exchange must take place in the same meeting, and not be of equal amounts. Accordingly, there is no blame on the company if it sells 1 Dollar for 103 Rupees rate, and there is no blame on you if you sell 1 Dollar for 106 Rupees rate or more, even if that is greater than its value in the market because the most important thing is that the exchange takes place in the same meeting if currencies are different. We have pointed out the guidelines of dealing in currency exchange online in Fatwa 88034, so please refer to it.
Allaah Knows best.