All perfect praise be to Allah. Blessing and peace be upon Prophet Mohammad and upon all of his family and companions.
The relationship between the card issuer and the card user-if there is money in his account-is that of guarantee and proxy payment, so it is impermissible for the bank issuing the card to charge a fee on it-except the actual cost of issuing it- since charging a fee on guarantee is impermissible according to the consensus of the four juristic schools. If the card user had no money in his account (the card isn`t covered) , then the relationship between the issuer and the user is that of guarantee and loan, so charging a fee on this basis isn`t permissible in order not to fall into usury.
However, if the issuer didn`t charge any of the ,aforementioned , unlawful fees, but the trader made an increase in the price of the commodity, or the service provided to the user, then it becomes a question of using trickery to evade the unlawful because the user of the card-in conclusion- is mulcted an unjust increase simply due to being a party in a deed of warranty, or loan, and this is unlawful in Islamic Law.
As a result, the Islamic Fiqh Assembly issued its resolution No.(108,2/12) which reads as follows: “It is permissible for the bank issuing the card to receive a commission on the purchases of its clients from the trader, provided that the latter sells by the credit card as he sells in cash.”
In conclusion, It is impermissible for gas stations, or traders to add any cash amount on whoever uses the credit card even if the aim was to make up for the commission received by the issuing party because this draws the transaction into the circle of doubtful things (Lawful/unlawful). The Messenger of Allah says in this regard: “ He who falls into doubtful things falls into that which is unlawful.” {Bukhari&Muslim}. And Allah Knows Best
