If developments occur that necessitate the elimination of the transaction basis on which the rent is based, the parties may request a judge to intervene in the contract and adjust the rent to the changing conditions. The request for adjustment can be made by either the tenant or the landlord. In this case, the tenant’s request involves a reduction in the rent, while the landlord’s request involves an increase due to the depreciation of the rent due to inflation. It should be noted that a lawsuit to adjust the lease to the changing conditions is subject to strict requirements. Indeed, the Court of Cassation has deemed adaptation cases “exceptional, secondary, or auxiliary.”
Court of Cassation, 3rd Civil Chamber, Date: September 11, 2018, Merits No: 2017/13096, Decision No: 2018/8263;
“Commitment to and respect for the contract are fundamental. It is not possible to adapt the contract to changing circumstances and conditions every time a request arises. Otherwise, there is a risk of deviating from the principles of “freedom of will,” “freedom of contract,” and “fidelity to the contract” that apply in our private law system. Intervention (adaptation) to the contract is exceptional, secondary, and auxiliary.”[2]
The first of these conditions is the occurrence of an unforeseeable and extraordinary change of circumstances. Article 138 of the Turkish Code of Obligations permits the adaptation of a contract only in the event of an extraordinary circumstance that did not exist at the time the contract was formed but subsequently arose. More clearly, adaptation of a contract is only possible if the circumstances subsequently change. Therefore, it is not possible to request an adaptation based on a situation that existed at the time the contract was formed. Furthermore, the subsequent change must relate to factors outside the contract. These include high exchange rate differences in foreign currency debt, extraordinary increases in rental prices due to inflation, and a decrease in harvest due to natural events. If a change has occurred in the elements of the contract’s content, the provisions regarding adaptation cannot apply to this change.
Secondly, the extraordinary situation must not have been caused by the party requesting the adaptation. In this context, no fault can be attributed to the party requesting the adaptation; the party requesting the adaptation must not be found at fault for causing the extraordinary situation.
Court of Cassation Civil Chambers General Assembly Merits No: 2014/1614, Decision No: 2014/900;
“…a) Caused by an unforeseeable external event: The external event in question must not be a personal event. Furthermore, this event must be unforeseeable and must have disrupted the balance of the contract without the fault of the party requesting the judge’s intervention.
b) Disruption of the economy of the contract: The judge can intervene within the framework of the Imprevision Theory only if the contract has not yet been performed. Unforeseeable events must have disrupted the balance between the parties. This is particularly the case in synallagmatic contracts, where the relationship between the act and the counter-act is disrupted.
c) The risk that can be objectively expected to be borne must have been exceeded. Federal Court precedents require that the imbalance be significant, clear, and excessive. Therefore, in each concrete case, an objective assessment must determine the maximum risk that the party invoking the Imprevision Theory must bear. If this risk has been exceeded, the judge may intervene in the contract.”[3]
The third requirement for adaptation is that the debtor cannot be expected to fulfill their obligation. In other words, only a subsequent fundamental and significant change must cause the foundation of the transaction to collapse, giving rise to the possibility of filing an adaptation lawsuit. It’s important to note that these changes are not limited to extreme difficulty of performance; adaptation lawsuits can also be filed in cases such as disruption of the balance of the performance and the failure of the intended purpose.
The fourth requirement is that the obligation has not yet been performed or has been performed with a reservation. A reservation is a declaration of intent by the tenant, when paying the rent, and the landlord, when accepting payment, reserving the right to file an adaptation lawsuit against the other party. It’s important to note that this declaration is not subject to any specific form of validity, but it’s beneficial to make it in writing. Furthermore, for the tenant’s request for an adaptation of the rent, the reservation need not be separate for each lease term. The tenant can ensure that this clause covers all rent payments made after the reservation is made, thus ensuring that it covers all rent payments. The Court of Cassation has ruled that the absence of a reservation clause does not necessitate the dismissal of the adaptation case. Furthermore, the Court of Cassation has ruled that the lessor may still claim a five-year retroactive rent difference even if the lessor has not objected for a long period.
Court of Cassation, 3rd Civil Chamber, Date: January 24, 2019, Merits No: 2018/7863, Decision No: 2019/534;
“The court did not conduct an expert examination as required by the reversal, and the case was dismissed on the grounds that the plaintiff tenant failed to pay the debt while reserving his rights arising from excessive hardship. The rent debt is a debt that is paid periodically, and payment does not terminate the obligation at once. The fact that the plaintiff tenant made the payment without reserving his rights arising from excessive hardship does not preclude the right to file an adaptation lawsuit.”[4]
The fifth condition for the adaptation of the rent is that the fundamental change in question occurred after the conclusion of the lease agreement. However, in cases where the debtor is in default, adaptation cannot generally be requested for extraordinary changes that occurred after the default. For example, if the foreign currency exchange rate increased after the debtor defaulted, the debtor would bear the risk and would not be able to request an adaptation of the contract, as this situation would not have been affected if the debt had been paid.
The sixth condition is that lease agreements must be long-term. This requirement stems from Supreme Court decisions. The Supreme Court adopts a restrictive approach regarding the acceptance of adaptation lawsuits for lease agreements, requiring the existence of a “long-term” lease agreement for a rent adaptation lawsuit to be filed. Considering the principles adopted by the Supreme Court, for the rental agreed upon by the parties to be adjusted to current conditions based on the transaction basis, there must be a long-term contract, extraordinary and unforeseen changes in the circumstances, these changes must be objective, and the continuation of the lease relationship must become intolerable under the extraordinary circumstances. Therefore, as a rule, it is not possible to request an adaptation for short-term lease agreements, such as one year. In such short-term agreements, the lessor has the right to request an increase in the rental amount for each subsequent year. Therefore, in short-term rental agreements, the rental fee agreed upon by the parties will be valid until the end of the term.[5]
[1] In this study, the following academic article was used: Kara Kılıçarslan, S. (2025). Kira Sözleşmelerinde Uyarlama Davası. Ankara Hacı Bayram Veli Üniversitesi Hukuk Fakültesi Dergisi, 29(2), 535-580. https://doi.org/10.34246/ahbvuhfd.1510350
[2] Court of Cassation, 3rd Civil Chamber, Date: September 11, 2018, Merits No: 2017/13096, Decision No: 2018/8263.
[3] Court of Cassation Civil Chambers General Assembly Merits No: 2014/1614, Decision No: 2014/900.
[4] Court of Cassation, 3rd Civil Chamber, Date: January 24, 2019, Merits No: 2018/7863, Decision No: 2019/534.
[5] Court of Cassation, 3rd Civil Chamber, Date: January 24, 2019, Merits No: 2018/7863, Decision No: 2019/534.