The maximum rate of rent increase to be applied in renewals of lease agreements is clearly determined in the Code of Obligations (M 344). Accordingly, the rate of rent increase can be as much as the rate of Domestic Producer Price Index. However, the announcement of four different Y values by TÜİK: “Change Rate According to Twelve-Month Averages”, “Annual Change Rate”, “Change Rate According to December” and “Monthly Change Rate” creates confusion. According to the settled decisions of the Supreme Court, the rate to be applied as the rent increase rate is the Rate of Change According to the Twelve-Month Averages. This rate is the highest rate of increase that can be applied in the renewal of lease agreements, and if it is lower than the rate of increase in the rent written in the agreement, the increase amount written in the agreement will be valid. On the contrary, if the rent increase is more than this rate, the determined rent increase rate will not be applied because it will be against the mandatory provisions of the law of obligations, the D-PPI rate will be applied.
