Is a credit card, used for shopping in installments at the same cash price, with interest added when installment payments are delayed due to insufficient balance, considered a usurious transaction?

The condition of adding interest to the amount when there isn't sufficient balance to pay an installment is a prohibited usurious condition. It is impermissible to accept it or enter into a contract that includes it, even if the intention is to pay early. The prevalence of this practice does not make it permissible. The Islamic Fiqh Council of the Muslim World League has ruled that this condition is void and impermissible, because it is the prohibited usury of the pre-Islamic era (Jahiliyyah).