Rent Determination Lawsuit in Turkey: Setting Market-Rate Rent After 5 Years

When a landlord's property has been let for many years and rent increases have not kept pace with the market, the lease may be delivering a rent that is a fraction of the property's true rental value. The rent determination lawsuit (kira tespiti davası) is the legal mechanism that allows a court to reset the rent to a fair market level. It is one of the most frequently litigated areas of Turkish rental law.

The Legal Basis

TBK Art. 344/3 provides that after a lease has continued for more than five years — or after the fifth year of a renewed lease — the rent for the next period is set by the court. The court determines the new rent by reference to:

• The CPI (Consumer Price Index) movement,
• The condition of the leased property,
• Comparable market rents in the locality.

The court is explicitly required to set a fair and equitable figure. In practice, the expert witness's comparables analysis drives the outcome, but the court retains discretion to apply an equity reduction.

Who Can Bring the Claim?

The claim is brought by the landlord. It is typically used when the parties cannot agree on the new rent after the five-year threshold has been crossed, and the current rent has fallen significantly below the prevailing market rate.

The five-year requirement is jurisdictional: if the lease has not yet run for five years, the court will reject the claim. The five-year period runs from the date the lease was originally signed.

The Expert Witness Process

Once the case is filed in the magistrates' court (sulh hukuk mahkemesi), the court appoints one or more expert witnesses. The expert's task is to:

1. Identify comparable leases — properties of similar type, size, condition and location — using data from the tax office, water authority, estate agents' associations, and other sources,
2. Assess the physical condition of the leased property,
3. Calculate the market rent for an equivalent property in the current market.

What Yargıtay Requires of Expert Reports

The Court of Cassation's 3rd Civil Division requires expert reports to be auditable: the source of each comparable must be stated, the methodology must be explained, and the conclusions must follow logically from the data. In its January 2026 rulings (see, e.g., E. 2025/3291, K. 2026/290), the Division confirmed that courts which rely on unsubstantiated or unsourced reports face reversal on appeal.

The Equity Reduction

After the expert establishes a market-rate figure, the court typically applies a downward equity adjustment to reflect the long-standing tenancy relationship. This reduction is commonly around 10% — though it varies depending on the length of the tenancy, the tenant's payment history, and prevailing economic conditions. The final figure the court orders is the adjusted market rent.

Effective Date of the New Rent

The new rent takes effect from the date the claim is served on the tenant, not from the date of the court's judgment. This means a landlord who delays filing loses the benefit of the higher rent for the period before service.

Court Fees

Filing fees in rent determination cases are calculated on the monthly rent difference (the gap between the current rent and the new rent), not on the annual total. Yargıtay has consistently rejected courts that charge fees on the full annual difference as contrary to law. Correct fee calculation saves both parties unnecessary cost.

Rent Determination vs. Adaptation Claim

The two should not be confused:

| | Rent Determination | Adaptation Claim | |---|---|---| | Legal basis | TBK Art. 344/3 | TBK Arts. 137–138 | | Trigger | 5-year threshold | Extraordinary change in circumstances | | Standard | Market comparables + equity | Balance of contract disturbed beyond expectation | | Frequency | Every 5 years | Exceptional; not routine |

Practical Considerations for Foreign Landlords

Foreign nationals who own property in Turkey and let it out are subject to the same rules. Several practical points are worth noting:

• Keep records of the original lease date — the five-year trigger is calculated from that date.
• Document the property's condition — photographs and inspection reports support the expert witness's assessment.
• File promptly — the new rent only runs from the date of service, so delay means lost income.
• Attend the hearing — in person or through a lawyer holding power of attorney.

Disputes in Practice

Comparables Disputes

The tenant may contest the expert's choice of comparables as unrepresentative — too upmarket, in better locations, or of higher specification. Landlords should be prepared to challenge comparables that understate market value.

Condition of the Property

Where the landlord has deferred maintenance, the expert may reduce the market rent to reflect the property's below-standard condition. Keeping the property in good repair is therefore in the landlord's commercial interest.

Commercial Properties

For factories, warehouses and large commercial units, market rents can run into hundreds of thousands of lira per month. Court fees and expert costs are proportionately significant; the financial stakes of the case justify thorough preparation.

Legal Assistance

Rent determination proceedings require careful preparation of comparables evidence, engagement with the expert witness process, and awareness of the Court of Cassation's requirements on what constitutes an acceptable expert report. MONA HUKUK handles rent determination cases for both landlords and tenants in Antalya.

Contact us at contact@monahukuk.com or call +90 (242) 606 14 32 to schedule a consultation.