Under Article 344 of the Turkish Code of Obligations (Türk Borçlar Kanunu, TBK), the rent increase applied in a renewed lease term for residential and roofed commercial premises cannot exceed the twelve-month average change in the consumer price index (TÜFE) over the previous lease year. Any agreed rate above that limit is not valid for the excess portion; the temporary 25% cap expired in July 2024 and no longer applies.
- Ceiling: the twelve-month average change rate of the CPI published by TÜİK (TBK Art. 344/1).
- If the contract states no rate, the judge sets the increase fairly, without exceeding the same ceiling.
- For leases longer than five years, the judge may redetermine rent taking comparable rents into account.
- A rent determination action may be filed at any time; for the result to bind the tenant from the start of the new term, it must be filed at least 30 days before that term, or the landlord must have given written notice of the increase within that period (Art. 345).
How is the rent increase rate calculated?
The Code limits the increase to "the twelve-month average change in the consumer price index in the previous lease year". This is the "12-month average change" column of the monthly CPI bulletin of the Turkish Statistical Institute (TÜİK). The bulletin for the month in which the lease renews is used.
Note that annual (year-on-year) inflation and the twelve-month average change are different figures; the statute refers to the latter.
Calculation example
The figures below are hypothetical and only illustrate the method; check the current TÜİK bulletin for the actual rate.
| Item | Value |
|---|---|
| Current monthly rent | TRY 20,000 |
| Assumed twelve-month average change | 40% |
| Calculation | 20,000 × 1.40 |
| Maximum new rent | TRY 28,000 |
As the example shows, the calculation applies the rate to the current rent, and the new rent becomes the base for the next renewed term. The lease year is the twelve-month period starting on the lease start date, so the increase follows the lease anniversary rather than the calendar year. The rate used is that of the bulletin for the renewal month and cannot be carried over from the previous year, as it changes annually.
What if the contract states a higher increase rate?
Article 344(1) provides that agreements are valid only if they do not exceed the twelve-month average CPI change. Even if the contract says "50% every year", the portion above that year's ceiling is not valid. The rule also applies to leases longer than one year. If no rate is agreed, the judge sets the rent, again within the same ceiling, considering the condition of the premises.
Is the 25% cap still in force?
No. Temporary Article 1 and Temporary Article 2 limited residential rent increases to 25%. Temporary Article 2 covers lease terms renewed between 2 July 2023 and 1 July 2024 (inclusive). For terms renewed afterwards, only the CPI limit in Article 344 applies.
How is rent set for leases longer than five years?
Under Article 344(3), for leases longer than five years, leases renewed after five years, and at the end of every subsequent five years, the rent for the new lease year is determined by the judge, who considers the CPI twelve-month average change, the condition of the premises and comparable rents. The CPI ceiling then ceases to be a binding cap and the judge's fair assessment applies.
When can a rent determination action be filed?
Under Article 345, the action may be filed at any time. For the rent set by the court to bind the tenant from the start of the new term, either the action must be filed at least thirty days before that term begins, or the landlord must have notified the increase in writing within that period. In that case the action may be filed until the end of the following lease term. If the contract itself provides for an increase in the new term, the rent set in an action filed by the end of the new term also applies from the start of that term.
Documents and place of filing
- The lease and any addenda,
- Bank receipts of rent payments,
- Any written increase notice (a notarised notice is easier to prove),
- Documents showing comparable rents (neighbouring leases, valuation report).
The action is filed before the civil court of peace (sulh hukuk mahkemesi) where the property is located. Check current rules on competence and court fees at the time of filing.
What happens if the increase is unpaid or overpaid?
If a tenant fails to pay a lawful increase, default consequences may follow; for eviction routes based on non-payment see Eviction of a Tenant Who Does Not Pay Rent (Kirayı Ödemeyen Kiracının Tahliyesi). Article 346 provides that no payment obligation other than rent and ancillary expenses may be imposed on the tenant, and that clauses providing a penalty for late payment or acceleration of later rents are invalid. A tenant who pays more than the lawful limit may claim a refund of the excess; the legal basis and limitation period must be assessed case by case.
Renewal and extension of the lease
Under Article 347, unless the tenant gives notice at least fifteen days before a fixed term ends, the lease is extended for one year on the same terms. The landlord cannot terminate based on expiry of the term; only after the ten-year extension period may the landlord terminate, with at least three months' notice before the end of each following extension year. Eviction for the landlord's own needs is separately regulated in Article 350.
How is the increase notified and what can the tenant do?
If the contract fixes a rate that does not exceed the CPI limit, it can be applied without a separate notice. If no rate is fixed or the parties disagree, the landlord can announce the increase by written notice to the tenant at least thirty days before the new term begins. Such notice matters for the rent later set in a rent determination action to bind the tenant from the start of the new term (Art. 345).
A tenant who believes the notified rate exceeds the CPI limit should check the twelve-month average change in the relevant TÜİK bulletin, pay by bank transfer with a description, and record the objection in writing. Bank receipts help prove both the rent and any overpayment. If the parties cannot agree, either the landlord or the tenant can file a rent determination action.
Is the rule different for commercial premises?
Article 344 applies the same twelve-month average CPI ceiling to residential and roofed commercial leases. The temporary 25% cap applied only to residential leases. Leases of unroofed property or special cases require a separate look at the contract and the general provisions.
It is also generally accepted that the first-term rent in a new lease with a new tenant can be freely agreed, while the CPI ceiling applies to subsequent renewed terms. As this point can be disputed in practice, the contract should be reviewed in the specific case.
Frequently Asked Questions
What is the maximum rent increase rate?
There is no fixed percentage. The ceiling is the twelve-month average change in the CPI bulletin for the renewal month (TBK Art. 344).
Has the 25% cap ended?
Yes. The period covered by Temporary Article 2 ended on 1 July 2024; later renewals are governed only by Article 344.
Must the landlord give written notice?
The statute does not make notice a condition of the increase itself, but the time and notice conditions in Article 345 matter for a court-set rent to bind the tenant from the start of the new term.
Is the tenant bound by a higher rate in the contract?
No; the portion above the twelve-month average CPI change is not valid.
How is rent set in leases over five years?
The judge sets a fair rent considering CPI change, the condition of the premises and comparable rents.
Can rent be raised in a foreign-currency lease?
Under Article 344(4), if rent is set in foreign currency, subject to Law No. 1567, it cannot be changed before five years have passed; the excessive performance difficulty provision remains reserved.