The nature and validity of the price adjustment clause by paying the difference at the time of payment of the last installment

The subject of this paper is the analysis of the nature and validity of price adjustment clause by paying the difference at the time of payment of the last installment. The unpredictable changes in commodity prices in the market have led to, in sales in installment, sellers cannot set a part of price allocated to installment, so they designed the above mechanism. This term concludes that, in the sale of installments, the last installment has been adjusted and the buyer is required to pay rest. In this paper, using a descriptive and analytical method and referring to the main sources, after analyzing the various forms of the above mechanism, it is recognized & this result has been achieved, If understanding of Gharar, and summarizes in assurance, this term will be correct. The judicial procedure also recognizes it's as valid. Keyword: installment sales, condition about performance of an act, corollary term suspended, adjustment, open price, Gharar.