September 2026 Rent Increase Rate Announced: TURKSTAT CPI Residential & Commercial Rent Increase Calculation

With the official inflation figures released by the Turkish Statistical Institute (TURKSTAT), the rent increase rate for September 2026 has been formalized. For both landlords and tenants whose contracts are up for renewal in September, the legal upper limit for rent increases is determined by the 12-month average Consumer Price Index (CPI).

Below are the official maximum rent increase rates, a sample calculation table, and key legal rights applicable to residential and commercial roofed properties for September 2026.

## What Is the Rent Increase Rate for September 2026?

Pursuant to Article 344 of the Turkish Code of Obligations (TBK), the statutory ceiling for rent increases is based on the 12-month average of the CPI.

* **September 2026 Legal Maximum Rent Increase Rate:** 31.79% * **Scope of Application:** Residential and commercial lease agreements * **Method of Implementation:** This rate serves as the maximum cap a property owner can apply; parties may mutually agree on a rate below this limit.

## How to Calculate the September 2026 Rent Increase

To calculate the new rent, multiply the current rent amount by the legal rate of 31.79% and add the result to your current rent.

New Rent Amount = Current Rent + (Current Rent × 31.79 / 100)

## September 2026 Sample Rent Calculation Table

* **10,000 TRY Current Rent:** Increase: 3,179 TRY | New Rent: 13,179 TRY * **15,000 TRY Current Rent:** Increase: 4,768.50 TRY | New Rent: 19,768.50 TRY * **20,000 TRY Current Rent:** Increase: 6,358 TRY | New Rent: 26,358 TRY * **25,000 TRY Current Rent:** Increase: 7,947.50 TRY | New Rent: 32,947.50 TRY * **30,000 TRY Current Rent:** Increase: 9,537 TRY | New Rent: 39,537 TRY * **50,000 TRY Current Rent:** Increase: 15,895 TRY | New Rent: 65,895 TRY

## Legal Rights and Regulations Concerning Rent Increases

* **Can the landlord demand an increase above 31.79%?** No. In accordance with Article 344 of the Turkish Code of Obligations, any demand exceeding the 12-month CPI average is legally void. As long as the tenant pays the increase up to the statutory limit via bank transfer, they cannot be placed in default or evicted on grounds of underpayment. * **What if a higher rate is written in the lease agreement?** Even if the contract specifies terms such as "A 50% increase shall apply annually" or "Increases will follow the PPI rate," any clause disadvantageous to the tenant is legally invalid under mandatory statutory provisions. The applicable ceiling remains 31.79%. * **The 5-Year Rule (Rent Determination Lawsuit):** If 5 years have elapsed since the start of the lease agreement, the landlord may file a Rent Determination Lawsuit to adjust the rent based on local market precedents, without being bound by the CPI cap. Prior to filing this lawsuit, participating in mandatory legal mediation is required.