I hope that you will beable to advise us about using Saudi Net cards [debit cards] when buying things that we need from the stores. These cards are used in the following manner: when the amount of the purchase has been added up, for example 150 riyaals, the card is given to the vendor and he passes (“swipes”) it through a machine that he has in his store. The value of the purchase is then taken instantly, by transferring the amount from the purchaser’s account to the vendor’s account in the same instant, i.e., before the buyer leaves the shop.
Praise be to Allaah.
If the matter is as you describe, there is no reason why these cards should not be used, if the purchaser has sufficient funds in his account to cover the required amount.
And Allaah is the source of strength. May Allaah bless our Prophet Muhammad and his family and companions, and grant them peace.
Standing Committee for Academic Research and Issuing Fatwaas. Fataawaa al-Lajnah al-Daa’imah, 13/527