What Is a Rent Determination Case in Turkey? When to File and How the Rent Is Set

1. What is a rent determination case and which leases does it cover?

When a lease is renewed, for example when a one-year lease is extended by law for another year because the tenant has not given notice at least 15 days before it expires (art. 347(1)), the parties may disagree on the rent for the new period. In a rent determination case the court sets the rent payable for that new period. The case does not end the lease; it only fixes the amount.

The rules below apply to residential and roofed commercial premises. They do not apply to properties intended for temporary use and let for six months or less (art. 339 [1]).

Do not confuse it with two other cases:

• Eviction case: aims to make the tenant leave. Refusing a proposed increase is not one of the statutory eviction grounds (arts. 347–352).
• Adaptation case: if an extraordinary, unforeseeable event seriously upsets the balance of the contract to the detriment of the debtor, the court can be asked to adapt the contract (art. 138 [1]). Its conditions differ from the CPI and five-year rules below.

2. How does the court set the new rent?

First five years: the CPI cap

Agreements on rent for renewed periods are valid only if the increase does not exceed the change in the 12-month average of the CPI in the previous lease year. This also applies to leases longer than one year (art. 344(1) [1]). The Turkish Statistical Institute (TÜİK) publishes the rate every month. Even if the contract states a higher rate, an increase above this cap cannot be demanded in the first five years.

If the contract has no increase clause and the parties cannot agree, the landlord cannot set the new rent alone. The judge sets it, again without exceeding the CPI rate, fairly and taking into account the condition of the property (art. 344(2) [1]).

After five years: comparable rents and fairness

For leases longer than five years, leases renewed after five years, and at the end of every following five-year period, the rent for the new lease year is set by the judge fairly, taking into account together (art. 344(3) [1]):

• the change in the 12-month average CPI,
• the condition of the property (location, size, quality of the building, etc.),
• comparable rents paid for similar properties nearby.

This applies even if the contract sets an increase rate. For example, in a one-year lease that began on 1 March 2020, the lease year starting on 1 March 2025 is the sixth year, and its rent may be set with reference to comparable rents. The rent set in this way may then change in the following years under the first-five-year principles, that is, within the CPI cap (art. 344(3), last sentence).

In practice: the "vacant letting" value and the equity reduction

The 3rd Civil Chamber of the Court of Cassation has described the method used after five years as follows. A court expert determines the rent the property would fetch if it were let vacant on the same terms. The judge then applies an equity reduction (hak ve nesafet indirimi) of between 5% and 20% in favour of the existing tenant, considering the length of the tenancy and the purposes the parties expected from the contract. Originals or certified copies of comparable leases should be obtained, and the expert should inspect the property and the comparables and compare features such as location, quality, use and lease start date. Commercial rents are set on a gross basis. An expert report without a comparison of comparables cannot form the basis of the judgment (Court of Cassation, 3rd Civil Chamber, 2025/6234 E., 2026/2844 K., 6 May 2026 [2]). In another case the Chamber upheld a judgment applying a 10% reduction (3rd Civil Chamber, 2026/484 E., 2026/3681 K., 9 June 2026 [3]).

The reduction rate is not set by statute; it is within the judge's discretion in each case.

Rent agreed in foreign currency

If the rent is agreed in a foreign currency, subject to Law No. 1567 on the Protection of the Value of the Turkish Currency, it cannot be changed for five years, without prejudice to the hardship rule in art. 138. After five years the five-year rule applies, also taking into account changes in the value of the currency (art. 344(4)). This article is based on rents in Turkish lira.

3. When must the case be filed? The timing conditions

A rent determination case can be filed at any time. However, for the rent set by the court to bind the tenant from the start of the new lease period, one of the following conditions must be met (art. 345 [1]):

4. Mediation before filing is mandatory

Since 1 September 2023, applying to a mediator before filing a case is a condition of action in disputes arising from a lease, meaning the court cannot examine the case without it. Eviction through summary enforcement proceedings without a judgment is excluded (Mediation Law art. 18/B [4]). A case filed without mediation is dismissed on procedural grounds; the final report stating that no agreement was reached must be attached to the statement of claim (art. 18/A(2)).

The process in brief:

1. Application: to the mediation office in the place of the competent court (or, where there is none, to the designated court registry) (art. 18/A(4)).
2. Meetings: the mediator concludes the matter within three weeks of appointment; in necessary cases this may be extended by up to one week (art. 18/A(9)).
3. Agreement: if the parties agree on the new rent, an agreement document is drawn up. In lease disputes an enforceability annotation must be obtained from the civil court of peace (art. 18/B(3)). An agreement with this annotation counts as a document equivalent to a court judgment and can be enforced (art. 18 [4]).
4. No agreement: the mediator issues the final report, and the case can then be filed.

5. Where and how is the case heard?

• Court: civil court of peace (sulh hukuk mahkemesi), regardless of the amount in dispute (Code of Civil Procedure art. 4(1)(a) [5]).
• Venue: as a rule, the court of the defendant's domicile (art. 6); contractual cases may also be filed where the contract is to be performed (art. 10).
• Procedure: the simple procedure applies (art. 316(1)(a)). The defendant has two weeks from service of the claim to respond (art. 317(2)). Each party must state all its evidence in its petition (art. 318). After the first hearing, the taking of evidence is in principle completed in two hearings no more than one month apart, although the judge may allow longer, giving reasons, for example where an expert examination takes longer (art. 320(3)).

Because the expert has to inspect the property and the comparables in person, the court may hold an on-site inspection with the expert. The law sets no fixed duration for the case; it depends on the court's workload and the expert examination.

What to prepare

• The lease and any later addenda
• Bank receipts showing rent paid
• The increase notice (for example a notarial notice) and proof of service
• The mediation final report
• Comparable leases, or information on where they can be obtained
• Documents showing the features of the property (land registry details, photos)

6. When does the decision apply, and when can the difference be claimed?

If one of the conditions above is met, the rent set by the court applies from the start of the new lease period (art. 345). Because the case takes time, a difference may build up between the rent paid and the rent set.

To collect this difference, finality of the judgment matters, meaning that no appeal is filed or appeal proceedings are completed. The 3rd Civil Chamber held that starting enforcement proceedings for the rent difference on the basis of a rent determination judgment that was not yet final was wrong, and that the action to set aside the tenant's objection to that enforcement should have been dismissed (3rd Civil Chamber, 2017/7339 E., 2019/5407 K., 13 June 2019 [6]).

A tenant who stops paying the current rent while the case is pending takes a separate risk: if rent that has fallen due is not paid, the landlord may give at least 30 days' written notice (for residential and roofed commercial premises) and state that the lease will be terminated if payment is not made (art. 315 [1]).

7. Hypothetical example

This example is purely hypothetical. A rented a flat on 1 September 2021 under a one-year lease; the lease has renewed automatically each year and the rent has risen by the CPI rate each year. The landlord, B, believes that the rent for the sixth lease year starting on 1 September 2026 is below comparable rents and, in July 2026, sends A a notarial notice of the increase. Mediation fails; before the new lease period ends, B files the case in the civil court of peace with the final report. The expert finds that the flat would fetch TRY 40,000 a month if let vacant; considering A's long tenancy, the court applies a 10% reduction and sets the rent at TRY 36,000. Because notice was given more than 30 days before the new period, this rent applies from 1 September 2026; enforcement of the difference has to wait until the judgment becomes final. In the lease year starting in September 2027, the rent may rise within the CPI cap.

8. FAQ

Can a tenant also file a rent determination case?

Yes. The 3rd Civil Chamber has stated that tenants, like landlords, may ask the court to determine the rent. In the same decision, a case filed after the period in question had ended was held to be one that should be dismissed (3rd Civil Chamber, 2013/680 E., 2013/1823 K., 7 February 2013 [7]).

Can my landlord evict me if I refuse the increase?

Refusing an increase is not a statutory eviction ground. The landlord also cannot end the lease merely because its term has expired; the separate right to terminate without reason, by notice, at the end of the ten-year extension period is unaffected (art. 347 [1]). If no agreement is reached, the landlord's route to an increase is mediation and a rent determination case.

Does the increase notice have to be sent through a notary?

The law requires written notice but not a notary (art. 345). The landlord, however, must prove that notice was given and when. A method that records the date of service, such as a notarial notice, makes this easier.

What happens if I do not attend the mediation meeting?

A party who misses the first meeting without a valid excuse is named in the final report. Even if that party later wins the case in whole or in part, it is liable for half of the costs the other side would have to pay, and only half of the lawyer's fee is awarded in its favour. If neither party attends, each bears its own costs (Mediation Law art. 18/A(11) [4]).

What does a rent determination case cost?

Court fees and an advance on costs set annually by the Ministry of Justice are paid on filing; the court may also set an advance for the evidence requested (Code of Civil Procedure art. 120 [5]). Amounts change every year. Costs are ultimately borne by the losing party, or shared in proportion if each side partly wins (art. 326). If mediation fails and the meeting lasts less than two hours, the two-hour fee is paid from the Ministry of Justice budget; this fee also counts as part of the court costs. If the parties agree, the fee is shared equally unless agreed otherwise (Mediation Law art. 18/A(12)–(13)).