Rent Adaptation Lawsuits in Turkey Due to Extraordinary Economic Conditions

Extraordinary economic, social and political developments may significantly affect the balance of a rental agreement. Severe economic crises, sudden currency fluctuations, extraordinary regulatory restrictions, pandemics, natural disasters, war, unexpected zoning changes or the collapse of a particular commercial market may make continued performance substantially more burdensome for one party.

Turkish law recognises that strict enforcement of a contract may become contrary to good faith where the circumstances forming the basis of the agreement change in an extraordinary and unforeseeable manner. Article 138 of the Turkish Code of Obligations No. 6098 therefore permits a party facing excessive hardship to request judicial adaptation of the contract.

However, a rent adaptation lawsuit is an exceptional remedy. It is not an alternative method that landlords may freely use whenever the contractual rent falls below current market advertisements. Nor does it automatically allow a commercial tenant to reduce rent merely because turnover has decreased or operating costs have increased.

The distinction between a rent adaptation lawsuit under Article 138 and a rent determination lawsuit under Article 344 is particularly important. For residential and roofed workplace leases, Turkish law already contains a specific statutory system governing annual increases and market-based rent determination. Current Court of Cassation practice states that ordinary inflation, reduced purchasing power and changes in comparable market rents must primarily be examined under Article 344 rather than being used to bypass the statutory rental system through Article 138.

At the same time, the Court of Cassation’s 3rd Civil Chamber clarified in its decision numbered E. 2024/1083, K. 2025/1439, dated 10 March 2025, that Article 138 has not become entirely inapplicable to rental agreements. Where circumstances different from the ordinary rent-determination criteria satisfy the strict requirements of excessive hardship, an adaptation lawsuit may still be filed.

This article explains the conditions, legal basis, procedural requirements, evidence and possible outcomes of rent adaptation lawsuits in Turkey as of July 2026.

What Is a Rent Adaptation Lawsuit?

A rent adaptation lawsuit is an action requesting the court to modify a rental agreement because extraordinary changes occurring after its conclusion have fundamentally disturbed the contractual balance.

The purpose is not simply to identify the present market rent. Instead, the court examines whether continued enforcement of the original contractual terms would be contrary to good faith because the circumstances forming the foundation of the agreement have collapsed.

The requested adaptation may concern:

• The amount of rent;
• The currency or payment mechanism;
• The payment schedule;
• The contractual duration;
• Turnover-based rental provisions;
• Common expense obligations;
• Temporary reductions or increases;
• The allocation of extraordinary operating costs; or
• Another contractual obligation directly affected by the extraordinary event.

Where adaptation is not reasonably possible, Article 138 allows the affected party to seek withdrawal from the contract. Because a rental agreement is a continuing contractual relationship, termination rather than retroactive withdrawal will generally be the relevant final remedy.

Legal Basis: Article 138 of the Turkish Code of Obligations

Article 138 regulates excessive hardship. The provision requires several cumulative conditions.

First, an extraordinary circumstance must occur after the contract was concluded. That circumstance must not have been foreseen by the parties and must be of a nature that the parties could not reasonably have been expected to foresee.

Second, the extraordinary circumstance must not arise from the party requesting adaptation.

Third, the change must alter the circumstances existing when the contract was concluded to such an extent that requiring performance would be contrary to the principle of good faith.

Finally, the affected party must either not yet have performed the relevant obligation or must have performed while expressly reserving the rights arising from excessive hardship.

If all conditions are present, the affected party may first request adaptation of the contract to the new circumstances. If adaptation is impossible, the party may seek withdrawal or, in continuing contracts such as leases, termination. Article 138 expressly states that it also applies to obligations denominated in foreign currency.

These conditions must be established together. Showing that rent has become financially inconvenient or that the economic environment has changed is not sufficient by itself.

The Principle of Pacta Sunt Servanda

Turkish contract law is based on the principle that agreements must be performed as concluded. This principle is generally referred to as pacta sunt servanda, or contractual fidelity.

Parties are expected to assess ordinary commercial and economic risks before signing. A business tenant assumes that customer demand may fluctuate. A landlord accepts that the property market may change. A party cannot ordinarily escape an unfavourable bargain simply because the contract later produces less profit than expected.

Article 138 creates an exception where the change is so extraordinary that insisting on strict performance would violate good faith. The remedy protects contractual justice, but it must be applied narrowly to preserve legal certainty.

The Court of Cassation describes adaptation as a mechanism for rebuilding the collapsed foundation of the transaction where unforeseeable changes have excessively disturbed the balance between the parties.

The Current Court of Cassation Approach

The relationship between Articles 138 and 344 has generated significant debate.

In earlier judicial practice, adaptation was frequently discussed in connection with long-term leases, severe inflation, devaluation, economic crises and major differences between contractual and market rent.

More recent Court of Cassation decisions have drawn a clearer distinction. In its decision numbered E. 2023/2580, K. 2024/792, dated 27 February 2024, the 3rd Civil Chamber stated that Article 344 is the specific statutory provision for determining rent in residential and roofed workplace leases. Consequently, inflation, reduced purchasing power, economic changes affecting market rent and comparable rental values should ordinarily be examined through Article 344 rather than Article 138.

A similar approach was reflected in the decision numbered E. 2023/4970, K. 2024/1277, dated 22 April 2024. The Court stated that the detailed system introduced by Article 344 replaced earlier distinctions under which different proceedings were used depending on the length of the rental agreement.

The Court of Cassation later resolved differing regional appellate approaches through its decision numbered E. 2024/1083, K. 2025/1439. It concluded that the criteria forming the subject matter of an Article 344 rent-determination action cannot simultaneously be treated as grounds for an Article 138 adaptation claim. Nevertheless, other extraordinary circumstances satisfying Article 138 may still support adaptation.

This 2025 decision is central to the current legal analysis.

Is Inflation Alone Sufficient?

Ordinary inflation alone will generally not support a rent adaptation claim concerning a residential or roofed workplace lease.

Article 344 already provides a system for protecting rent against inflation. Annual agreements concerning renewed rental periods are subject to the statutory index limitation. After five years, the court may consider the Consumer Price Index, the condition of the property, comparable rents and equity when determining the new rent.

The Court of Cassation has therefore stated that a landlord cannot use Article 138 before the completion of five years merely because current market rents have increased more rapidly than the statutory increase rate. Permitting this would allow the special system established by Article 344 to be bypassed.

This does not mean that an economic crisis can never be relevant. The question is whether the claimant relies only on inflation, purchasing-power loss and comparable rents or establishes an additional extraordinary event that fundamentally affects the contractual relationship.

Extraordinary Economic Conditions That May Be Relevant

The 2025 Court of Cassation decision gives examples of circumstances that may potentially fall outside ordinary rent-determination criteria. These include natural disasters, pandemics, war, coups, extraordinary zoning changes, unforeseeable commercial developments, abnormal increases in taxation or depreciation expenses, sudden and extreme currency movements and severe economic crises affecting the contractual basis.

The existence of one of these events does not automatically establish excessive hardship.

The claimant must also prove:

• The direct effect of the event on the particular rental relationship;
• That the effect was not reasonably foreseeable when the contract was signed;
• That the claimant did not cause the problem;
• That the risk was not contractually assumed;
• That the contractual balance was fundamentally disturbed; and
• That continued performance would violate good faith.

A nationwide crisis may affect different businesses in different ways. A hotel forced to remain closed by public restrictions will not be assessed in the same manner as a business whose activity continued normally.

Adaptation Following a Pandemic

Pandemic-related restrictions generated numerous adaptation disputes, particularly concerning hotels, restaurants, shopping-centre units, entertainment businesses and tourism facilities.

A pandemic may constitute an extraordinary circumstance, but the claimant must establish how government restrictions, closures, travel limitations or operational prohibitions affected the specific premises and contractual obligations.

A general reduction in turnover is not necessarily sufficient. The court may examine whether the business was legally prohibited from operating, whether alternative activities remained possible, whether state support was received, how long the restrictions continued and whether the agreed rent could still reasonably be paid.

In a decision concerning a hotel lease, the Court of Cassation held that an adaptation could not reduce rental debts retrospectively for periods arising before the filing date. The Court indicated that, where adaptation is justified, the modified rent should generally take effect from the lawsuit date rather than changing previously accrued rent retroactively.

Earthquakes and Natural Disasters

An earthquake, flood, major fire, landslide or similar disaster may affect a rental agreement in several legally distinct ways.

If the property becomes completely unusable, rules concerning impossibility, defects or termination may apply rather than Article 138.

If the property remains technically usable but access, commercial activity, customer demand, infrastructure or regional economic conditions are extraordinarily affected, adaptation may become relevant.

The claimant must identify whether the problem concerns:

• Physical damage to the property;
• Loss of lawful use;
• Government restrictions;
• Regional evacuation;
• Collapse of commercial activity;
• Increased operational expenses; or
• A broader disturbance of the contractual balance.

Article 138 should not be used where another more specific legal remedy directly regulates the circumstances. The legal basis must be selected according to the actual nature of the problem.

Sudden Currency Fluctuations

Article 138 expressly applies to foreign-currency obligations. Article 344 also preserves the application of Article 138 where rent has been validly determined in foreign currency.

However, a change in the exchange rate does not automatically justify adaptation.

Currency fluctuation is a known feature of economic life. The party requesting adaptation must prove that the movement was exceptionally severe, that its scale and effect could not reasonably have been anticipated and that the contractual balance became intolerable.

Courts may also examine:

• The duration of the contract;
• The currency in which the claimant earns income;
• Whether the claimant is a merchant;
• The existence of currency-adjustment clauses;
• The parties’ previous experience;
• The allocation of exchange-rate risk; and
• Whether the claimant voluntarily chose the foreign currency.

A company earning revenue in the same foreign currency as the rent may have greater difficulty proving excessive hardship than a party whose income and obligations became unexpectedly mismatched.

Separate Turkish currency-protection regulations must also be reviewed to determine whether the foreign-currency rent clause itself is legally permissible.

The Importance of Foreseeability

Foreseeability is one of the most difficult requirements in an adaptation case.

The event must not only have been unforeseen; it must also be an event that the parties could not reasonably have been expected to foresee when the agreement was concluded.

The date of the contract is therefore critical.

A party entering into a long-term lease during an already unstable economic period may be expected to anticipate some level of inflation, exchange-rate movement or demand fluctuation.

However, even where the type of event was foreseeable in general, its exceptional magnitude or consequences may arguably have exceeded what could reasonably have been anticipated.

The assessment is objective and specific to the parties. The court may consider their commercial experience, professional status, negotiations, contract duration and the information available when the agreement was executed.

Commercial Tenants and the Duty of Prudence

Commercial tenants are not excluded from Article 138. However, a merchant is generally expected to act prudently and assess commercial risks when entering into a long-term agreement.

Court of Cassation decisions have rejected adaptation claims where a commercial claimant failed to establish the strict Article 138 requirements and the circumstances fell within ordinary commercial risk.

A business claimant should therefore present more than general economic statistics.

Relevant evidence may include:

• Audited financial statements;
• Turnover comparisons;
• Sector-specific market reports;
• Government closure decisions;
• Licence restrictions;
• Occupancy rates;
• Cost structures;
• Exchange-rate exposure;
• Employee and operational expenses;
• Customer-volume data; and
• Evidence that the impact could not reasonably be mitigated.

The court may also examine whether the tenant continued operating, received state assistance, reduced other expenses or generated income through alternative channels.

Must the Claimant Have Avoided or Reserved Performance?

Article 138 provides that the affected party must not yet have performed the obligation or must have performed while reserving rights arising from excessive hardship.

This requirement is particularly important for tenants who continue paying rent while considering adaptation.

A tenant who pays each monthly rent in full without reservation may face difficulty seeking repayment or reduction of those completed payments later.

To protect the position, the affected party may send a written notice stating that payment is being made under reservation and without waiving the right to request adaptation.

The reservation should identify:

• The extraordinary circumstance;
• The contractual provision affected;
• The period concerned;
• The right to seek judicial adaptation; and
• The fact that payment is made to avoid default, enforcement or eviction.

The reservation does not guarantee that the adaptation claim will succeed. It preserves the argument that performance did not amount to unconditional acceptance of the original terms.

Should the Tenant Stop Paying Rent?

A tenant should not stop paying rent merely because an adaptation lawsuit is being considered or filed.

The filing of the action does not automatically modify the contract. Until the parties reach an agreement or the court issues an effective decision, the existing contractual obligation generally continues.

Non-payment may expose the tenant to:

• Default interest;
• Enforcement proceedings;
• A payment order;
• Eviction proceedings; and
• Additional legal costs.

A general court adaptation action does not automatically suspend a separate enforcement proceeding before the enforcement court. Court of Cassation practice has stated that an adaptation case pending before the ordinary court does not necessarily become a preliminary issue stopping the limited enforcement-court procedure.

The tenant may continue paying under an express reservation and request appropriate interim protection where the legal conditions exist.

Can an Interim Injunction Be Requested?

A party may request an interim injunction, but relief is not automatic.

Under Articles 389 and 390 of the Code of Civil Procedure, an injunction may be granted where a change in the existing situation could make enforcement of the right substantially difficult or impossible, or where delay could cause serious harm. The applicant must explain the requested measure clearly and approximately prove the merits of the claim.

In an adaptation dispute, the claimant may request temporary regulation of payment obligations pending the final judgment.

The court will consider:

• The strength of the evidence;
• The seriousness of the hardship;
• The risk of irreparable damage;
• The interests of the landlord;
• The amount proposed to be paid;
• The possibility of security; and
• Whether the requested measure would effectively decide the merits prematurely.

The claimant should not assume that filing an injunction request permits unilateral payment of a reduced amount before the court decides.

Rent Adaptation and Rent Determination: The Main Difference

A rent determination lawsuit under Article 344 and an adaptation lawsuit under Article 138 serve different purposes.

A rent determination lawsuit establishes the rent for a renewed rental period under the statutory rental system. For residential and roofed workplace leases, the court considers the applicable index and, after five years, the condition of the property, comparable rents and equity.

An adaptation lawsuit is based on the collapse of the contractual foundation because of an extraordinary and unforeseeable event.

The distinction may be summarised as follows:

The Court of Cassation’s 2025 decision emphasises that the criteria used in a rent-determination case cannot simply be relabelled as grounds for adaptation.

Is There a Five-Year Requirement?

Article 138 does not contain a general five-year waiting period.

Where the claimant relies on a genuine Article 138 event distinct from the ordinary criteria of Article 344, adaptation may be requested without waiting for the completion of five rental years.

The Court of Cassation’s 2025 decision expressly states that where the other grounds and conditions of Article 138 exist, an adaptation lawsuit may be filed at any time.

However, a landlord cannot avoid the five-year market-rent system by describing ordinary inflation and higher comparable rents as excessive hardship.

If the claim is essentially that the existing residential rent is below current market levels, the correct remedy will ordinarily be rent determination under Article 344.

Who May File the Lawsuit?

An adaptation claim may be relevant to either side of a rental relationship, depending on which contractual obligation has become excessively burdensome.

A commercial tenant may request a temporary reduction where extraordinary restrictions have made continued payment intolerable.

A landlord may request adjustment where a contractual arrangement has been fundamentally affected by an extraordinary event not governed exclusively by the Article 344 rent-determination system.

However, a landlord seeking only to increase residential or roofed workplace rent because of inflation and comparable market prices should generally rely on Article 344.

The claimant must have a present legal interest and must identify the exact contractual obligation requiring adaptation.

Mandatory Mediation Before Litigation

Rental disputes are generally subject to mandatory mediation before a lawsuit is filed.

Article 18/B of the Mediation Law includes disputes arising from rental relationships, except for the specific non-judicial eviction procedures under the Enforcement and Bankruptcy Law. A rent adaptation action therefore requires a prior mediation application.

The mediation application should identify:

• The rental agreement;
• The extraordinary event;
• The provision requiring adaptation;
• The existing rent or payment structure;
• The proposed adjusted terms;
• The requested effective date;
• Payments made under reservation;
• Supporting financial information; and
• Any alternative termination proposal.

If the parties cannot agree, the mediator issues a final non-settlement report. The claimant may then file the lawsuit.

A case filed without completing mandatory mediation is subject to procedural dismissal.

The period from the mediation application until the final report is issued is not counted for limitation and forfeiture purposes.

Settlement Through Mediation

Adaptation disputes are particularly suitable for mediation because the parties may create solutions that are more flexible than a court judgment.

They may agree on:

• A temporary rent reduction;
• A gradual rent increase;
• Postponement of payments;
• Instalments for accumulated debt;
• Conversion of the rental currency;
• A turnover-based payment;
• Extension of the lease;
• A rent-free period;
• Revision of common expenses;
• Mutual termination; or
• A definite evacuation date.

The agreement should clearly state the duration and scope of the adaptation.

For example, a clause stating that rent will be reduced “during the economic crisis” is too uncertain. The agreement should identify exact dates, amounts and conditions for returning to the original payment structure.

An agreement prepared under Article 18/B requires the statutory enforceability annotation from the competent Civil Court of Peace.

Which Court Has Jurisdiction?

Civil Courts of Peace, known as Sulh Hukuk Mahkemeleri, hear disputes arising from rental relationships regardless of the monetary value of the claim.

Article 4 of the Code of Civil Procedure assigns rental disputes, including rental receivable cases, to these courts, except for the special non-judicial eviction provisions.

The action may generally be filed before:

• The court at the defendant’s residence; or
• The court at the place where the rental agreement is performed.

Article 10 of the Code of Civil Procedure permits contractual actions to be filed at the place of performance.

A contractual jurisdiction clause may also require examination, particularly where both parties are merchants.

When Can the Lawsuit Be Filed?

Article 138 does not prescribe a special filing period equivalent to the Article 345 timing rules for rent determination.

Nevertheless, the claimant should act promptly after the extraordinary event and after it becomes clear that the contractual balance cannot be restored through negotiation.

Delay may raise questions about:

• Whether the event was genuinely intolerable;
• Whether the claimant accepted the original terms;
• Whether payments were made without reservation;
• Whether the contractual relationship has already ended; and
• Whether the claimed hardship still continues.

The 2025 Court of Cassation decision confirms that adaptation may be sought whenever the separate Article 138 conditions are satisfied, but the factual and legal interest must still exist when the action is filed.

Can Adaptation Apply Retrospectively?

The claimant should not assume that the court will revise all past rental debts from the date on which the extraordinary event first occurred.

In its decision numbered E. 2023/5655, K. 2024/3726, the Court of Cassation held that rental debts arising before the lawsuit date could not be retrospectively reduced through adaptation. It stated that adaptation should be ordered with effect from the lawsuit date.

This makes prompt legal action and a written reservation particularly important.

Where the claimant continues to pay without reservation for a long period and later requests repayment of completed rental instalments, the claim may face substantial legal difficulties.

The exact effective date must be formulated clearly in the mediation application and statement of claim.

Evidence Required in an Adaptation Case

A successful adaptation claim requires detailed evidence establishing both the extraordinary event and its specific effect on the contract.

The claimant should submit:

• The original rental agreement;
• All amendments and protocols;
• Payment records;
• Written adaptation requests;
• Reservations of rights;
• Official restriction or closure decisions;
• Financial statements;
• Tax records;
• Turnover reports;
• Sector data;
• Expert reports;
• Currency and cost analyses;
• Property-use records;
• Licence documents;
• Insurance records;
• Evidence of mitigation efforts; and
• Correspondence between the parties.

General newspaper articles or broad economic statistics will rarely be sufficient alone.

The claimant must establish causation. The court must be able to see how the extraordinary event changed the specific contractual balance.

Expert Examination

Adaptation cases commonly require expert evidence.

Depending on the dispute, the court may appoint specialists in:

• Real estate valuation;
• Accounting;
• Finance;
• Economics;
• The tenant’s commercial sector;
• Construction;
• Tourism;
• Hotel management; or
• Another relevant technical field.

The experts may examine the original financial assumptions, the impact of the extraordinary event, the claimant’s income and expenses, the remaining contract duration, market conditions and possible adaptation models.

The Court of Cassation has stated that an adaptation assessment may require examination of the property’s characteristics, sudden currency movements, serious economic crises, natural disasters, abnormal commercial changes, taxes, depreciation expenses and other circumstances affecting the contractual basis.

The expert does not make the final legal decision. The judge determines whether Article 138 applies and which adaptation is consistent with good faith.

How Does the Court Determine the New Terms?

Article 138 does not prescribe a fixed mathematical formula.

The court must choose a solution that restores the contractual balance while interfering with the parties’ agreement only to the extent necessary.

Possible judicial outcomes may include:

• Temporary reduction of rent;
• Adjustment of the payment schedule;
• Modification of the contractual currency;
• Revision of a turnover-rent provision;
• Adjustment of the duration;
• Partial allocation of extraordinary costs;
• Rejection of the claim; or
• Termination where adaptation is impossible.

The court should consider the interests of both sides. Adaptation should not transfer the entire loss to the other party or provide the claimant with an unjustified commercial advantage.

Contractual Adaptation Clauses

A well-drafted long-term rental agreement may contain a hardship or adaptation clause.

Such a clause may define:

• Which events qualify as extraordinary;
• When renegotiation begins;
• What documents must be provided;
• Whether payments continue during negotiation;
• The adjustment formula;
• The negotiation period;
• Expert appointment;
• Termination rights; and
• Dispute-resolution procedures.

The existence of a clause does not necessarily prevent Article 138 from applying.

The court may examine whether the parties already allocated the relevant risk. If the contract clearly assigns exchange-rate, inflation, closure or regulatory risk to one party, this may weaken an adaptation request.

Conversely, enforcing a clause may itself become contrary to good faith where the actual event and consequences greatly exceed the risk reasonably contemplated by the parties.

Common Mistakes Made by Landlords

A common mistake is treating Article 138 as a method for bypassing the five-year requirement under Article 344.

Higher market advertisements, ordinary inflation and reduced purchasing power will generally not be enough for this purpose.

Other frequent mistakes include:

• Failing to identify an extraordinary event distinct from rent inflation;
• Requesting full vacant market rent through adaptation;
• Seeking retrospective differences for past periods;
• Failing to complete mandatory mediation;
• Relying only on general economic statistics;
• Ignoring the contractual risk allocation;
• Failing to prove the effect on the specific property; and
• Confusing adaptation with rent determination.

A landlord should first determine whether the actual claim falls under Article 344 or Article 138.

Common Mistakes Made by Tenants

Tenants frequently assume that business losses automatically justify a rent reduction.

A decline in turnover may reflect ordinary commercial risk rather than excessive hardship.

Other common errors include:

• Stopping all rent payments;
• Paying without reserving rights;
• Waiting until enforcement begins;
• Failing to document the extraordinary event;
• Presenting only company-wide losses without connecting them to the rented premises;
• Ignoring state support or alternative revenue;
• Requesting retrospective reduction of completed payments; and
• Filing without mandatory mediation.

The tenant should continue protecting the rental relationship while pursuing adaptation through a legally structured process.

Practical Strategy Before Filing

The party considering adaptation should first conduct a legal classification.

The analysis should determine:

1. Whether the dispute is actually a rent-determination issue under Article 344;
2. Whether a more specific remedy concerning defects, impossibility or termination applies;
3. Whether an extraordinary Article 138 event exists;
4. Whether the event was foreseeable;
5. Whether the contract allocated the risk;
6. Whether performance has been made under reservation;
7. What precise adaptation is requested; and
8. Whether continued performance remains possible.

The affected party should then send a written adaptation proposal, preserve rights, collect financial evidence and commence mandatory mediation.

The requested adjustment should be proportionate and supported by a realistic calculation.

Frequently Asked Questions

What is a rent adaptation lawsuit in Turkey?

It is a lawsuit requesting modification of a rental agreement because an extraordinary and unforeseeable event has fundamentally disturbed the contractual balance.

Is high inflation sufficient?

Not ordinarily for residential and roofed workplace leases. Inflation, purchasing-power loss and comparable rents are generally addressed through Article 344.

Can Article 138 still apply to a rental agreement?

Yes. The Court of Cassation confirmed in 2025 that an adaptation claim may be filed where separate circumstances satisfying Article 138 exist.

Is there a five-year waiting period?

There is no universal five-year period for a genuine Article 138 claim. However, Article 138 cannot be used merely to bypass the five-year market-rent system under Article 344.

Can a tenant request a rent reduction?

Yes, where the tenant proves all excessive-hardship conditions and establishes that the extraordinary event directly affected the contractual balance.

Can a landlord request an increase?

Potentially, but ordinary inflation and higher market rents must generally be pursued through Article 344 rather than Article 138.

Can the lawsuit revise earlier rental debts?

Current Court of Cassation practice indicates that adaptation should generally operate from the lawsuit date and should not retrospectively reduce rental debts already accrued before filing.

Should the tenant continue paying rent?

Yes. Filing an adaptation claim does not automatically suspend the existing obligation. Payments may be made under an express reservation.

Is an interim injunction possible?

It may be requested, but the claimant must establish the statutory urgency and approximately prove the merits. The court has discretion.

Is mediation compulsory?

Yes. A rent adaptation lawsuit is subject to mandatory mediation before litigation.

Which court hears the case?

The Civil Court of Peace generally has subject-matter jurisdiction.

Can foreign-currency rent be adapted?

Article 138 applies to foreign-currency obligations, and Article 344 expressly preserves excessive-hardship claims concerning valid foreign-currency rent arrangements.

Can a pandemic justify adaptation?

Potentially. The claimant must prove the specific legal and economic effect of the restrictions on the rented property and contractual performance.

Does a decrease in turnover automatically justify adaptation?

No. Ordinary business losses and commercial risks are not sufficient without proof of unforeseeable excessive hardship.

Conclusion

Rent adaptation lawsuits in Turkey provide an exceptional method of protecting contractual justice where an unforeseeable and extraordinary event fundamentally changes the circumstances existing when a lease was concluded.

The legal basis is Article 138 of the Turkish Code of Obligations. The claimant must prove an unforeseeable extraordinary event, absence of fault, a fundamental disturbance of the contractual balance and non-performance or performance under an express reservation of rights.

However, residential and roofed workplace leases are also governed by the specific rent-determination system under Article 344.

Current Court of Cassation practice makes a clear distinction. Ordinary inflation, reduced purchasing power, changes in comparable rents and the difference between contractual and market rent belong primarily to a rent-determination case. They cannot ordinarily be used to bypass the statutory five-year framework through an Article 138 adaptation claim.

The Court of Cassation’s 2025 decision nevertheless confirms that Article 138 remains available where other extraordinary circumstances affect the contractual foundation. Natural disasters, pandemics, war, extraordinary regulatory changes, unforeseeable commercial developments and severe currency disruptions may be relevant where their specific impact and all statutory conditions are proven.

The outcome depends heavily on evidence. Financial records, official restrictions, sector reports, payment reservations, expert analysis and proof of causation are essential.

The claimant should not stop performing unilaterally. Rent should generally continue to be paid unless the parties agree otherwise or the court grants an appropriate interim measure.

Adaptation generally operates prospectively, and current judicial practice does not support using the remedy to reduce rental debts retrospectively for periods before the lawsuit.

Mandatory mediation must be completed before the case is filed, and the Civil Court of Peace generally has jurisdiction.

Because the distinction between adaptation, rent determination, defect remedies and termination is legally decisive, each rental dispute should be analysed individually before a notice, mediation application or lawsuit is prepared.

Legal Disclaimer: This article provides general information concerning rent adaptation lawsuits in Turkey and does not constitute legal advice. Each claim must be assessed according to the rental agreement, contractual risk allocation, date and nature of the extraordinary event, payment records, reservations of rights, financial evidence, mandatory mediation process and current judicial practice.