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 is His slave and Messenger.
Selling by instalment (i.e. selling a product- a car or else), which is selling with a delayed payment whether the delayed payment is in one lump sum or by instalments, is permissible.
If this sale is done through the bank, it is a condition that the bank possesses the goods before selling it to the customer. Once the bank possesses the goods, it is permissible for it to sell it according to the price agreed between it and the customer.
After the ownership of the goods is transferred to the customer, then it is permissible for him to dispose of it like an owner even if he did not pay its full price or did not pay any amount of its price at all. The permissibility of him disposing of it as he wishes depends on the ownership and this took place by the sale contract and possessing the goods, as long as there is no condition in the sale contract, like mortgaging the goods for its price, or preventing the buyer from selling it unless he pays its price, because if such condition exists, it must be fulfilled.
The Islamic Fiqh resolution reads: “It is permissible for the seller to condition on the buyer the mortgage of the sold goods with him so that he guarantees his right for all instalments to be paid.”
Finally, it should be noted that if the contract includes an additional payment on the debt in case the customer delays the payment, then this transaction is forbidden.