A man sells cars on installment, and the installments are not paid within the agreed period?

Question:
The questioner says: A man sells cars on installment, and the installments are not paid within the agreed period.

Answer:
There is no harm, but he must not increase the amount. If he sells on installment and the buyer is unable to pay, he should give him time. If he is unable to pay, he is required to deliver the goods, but if he gives him time, he must not increase the amount. If he increases it, this becomes the riba of the pre-Islamic age of ignorance, which is not permissible. If the installment is due in Ramadan and the buyer is not able to pay, he should give him time, even if the buyer is in Shawwal or Dhu al-Qa'dah. But he must not increase the amount. He should not say, "Since it has not come due, I will add ten or twenty to it." No, that is riba, and it is not permissible. He should give him time without any increase. There is no excuse except with a guarantee, meaning without any increase. If it was the pre-Islamic age of ignorance, they would say, "Either you pay with interest or you pay it off. Either you pay it off now or we will increase the amount on you." If the amount was ten, they would say, "Pay twelve and we will give you two, three, or four months, and so on."