The Ruling on Discounts for Paying Installments

Question: The brother / A. S. A. from Riyadh says in his question: It is customary in private schools that installment payments are made in two periods, before the start of the first semester and before the start of the second semester. Some schools write to the guardian before the start of the school year that if he pays both installments together before the start of the school year, he will receive a discount of such and such a percentage. Is this permissible in our pure religion? We ask for a ruling, and we thank you.
Answer: There is no harm in that according to the most correct of the scholars’ opinions; because of the clear benefit for both parties. And Allah is the One who grants success.