1. Practical importance of the issue: What does five years change?

In rental law, five years is not just a calendar threshold; it is a turning point that fundamentally changes the method by which the rent amount is determined.

• Before five years pass: The annual increase is limited to the change rate based on the twelve-month averages of CPI for the previous rental year. Even if a higher rate is specified in the contract, this limit cannot be exceeded.
• After five years: The judge, without being bound by the CPI ceiling; determines a fair price, considering the condition of the property and comparable rental prices. In rents that have remained far below the market, the difference can be manifold.

Therefore, the question of “has five years passed or not?” determines the essence of the case in most files. However, when the property changes hands and a “new” contract is signed on paper with the new owner, the starting date of the period becomes seriously debatable. This is precisely the subject of this article.

2. Legal framework: Turkish Code of Obligations Art. 344, Art. 345 and Art. 310

2.1. Turkish Code of Obligations Art. 344 — Determination of the Rent Price

Article 344 of the Turkish Code of Obligations numbered 6098 establishes a three-tiered system:

• f.1 – If there is an agreement: The increase agreed upon by the parties for renewed periods is valid provided that it does not exceed the twelve-month average change rate of the CPI for the previous rental year.
• f.2 – If there is no agreement: The rent is determined by the judge in accordance with equity, taking into account the condition of the leased property, provided that it does not exceed the same ceiling.
• f.3 – After five years: Regardless of whether there is an agreement, in contracts exceeding five years or renewed after five years, and at the end of every subsequent five-year period, the rent; is determined by the judge in accordance with equity, considering the CPI change rate, the condition of the leased property, and comparable rental prices.

This regulation of the Law is mandatory in nature. As emphasized in established case law:

The practical consequence of this is as follows: Even if the parties include clauses in the contract such as “the five-year period recommences” or “the tenant waives their right to equity”, these clauses, being against the tenant, are not considered valid.

2.2. TCO Art. 345 — Period for filing a lawsuit and the effect of the decision

A lawsuit for the determination of the rent amount can be filed at any time. However, for the amount to be determined by the court to be binding on the tenant from the beginning of the new rental period, the lawsuit must have been filed at the latest thirty days before the beginning of the new period, or the landlord must have given written notice to the tenant within this period. If there is a provision in the contract regarding the increase of the rent amount in the new period, a lawsuit filed until the end of the new period, without the need for a separate warning, will also yield the same result.

2.3. TBK Art. 310 — Change of Ownership of the Leased Property

“If the leased property changes hands for any reason after the establishment of the contract, the new owner becomes a party to the lease agreement.” This provision has reversed the understanding of “sale breaks the lease” from the period of the former Code of Obligations numbered 818 and adopted the principle that “sale does not break the lease.” The entire answer of the article essentially lies in this clause.

3. Legal Meaning of the Five-Year Period

The five-year period is a period of stability granted to protect the tenant from sudden and unforeseeable rent increases. The legislator has provided the tenant with a predictable increase regime limited by indexation during this period; and at the end of the period, allowed the rent to be brought closer to market realities to protect the landlord’s property rights.

The date taken as the basis for calculating the period is the date when the lease relationship actually and legally began; not how many times the contract was renewed or how many separate documents were signed. For our detailed examination of this matter: How to File a Rent Determination Lawsuit Upon Expiry of the Five-Year Period in Light of Court of Cassation Decisions?

4. “Sale does not break the lease”: Succession of the new owner

In case of sale, donation, inheritance, or transfer through forced execution of the immovable property, the new owner becomes the lessor party of the existing lease agreement. They are responsible for the obligations arising from the contract, just as they are the owner of the rights. The new owner is not considered to have “established the lease relationship from scratch.”

The natural consequence of this principle: The transfer of ownership does not extinguish the tenant’s accumulated five-year “seniority.” Accepting the opposite would allow lessors to easily circumvent the tenant’s legal protection by transferring the property to a relative, which is incompatible with the public order nature of Article 344.

5. Rule: A renewal contract does not reset the five-year period

In practice, new owners prefer to sign a “new” lease agreement with the tenant after purchase. The purpose is usually innocent: to update party information, IBAN, and the lease start date. However, this document is often legally not a new independent contract, but a renewal (tecdit) of the existing relationship.

Current case law is along the same lines:

6. Decisive criterion: Market rate test

The common denominator of judicial decisions is clear: Courts look not at the contract’s title, date, or the phrase “it is a new contract”, but at its economic content. The only question asked is:

The logic behind this test is as follows: The five-year protection is in return for the tenant’s rent detaching from the market over time. If the rent has already been adjusted to the market, there is no ‘detachment’ left to protect; the protection restarts.

7. Exception: Cases where the period restarts

7.1. Establishment of a genuinely new contract

7.2. Inability to prove the previous contract

8. Summary table and decision flow chart

9. How is “compliance with market rate” measured in practice?

The law does not provide a definition for “market rate”; the criterion is materialized through jurisprudence and expert examination. The criteria actually considered by the courts are as follows:

• Comparable lease agreements: Originals or certified copies of agreements for properties of similar nature in the same building, same street, or same neighborhood.
• Specific characteristics of the property: Location, gross/net area, floor, facade, age, elevator-parking situation, renovation level, and if it’s a workplace, street/corner location and customer circulation.
• Nature of the increase rate: Is the increase made in the new contract a symbolic increase close to the index rate, or a significant jump adjusted to the market?
• The wording of the contract and surrounding circumstances: Records that the leased property was “delivered vacant”, collection of a new deposit, a new guarantor, changes in subscriptions — these are strong presumptions in favor of a genuinely new relationship.
• Continuity of factual situation: The tenant’s uninterrupted possession, continued use of the same subscriptions, and making payments to the same IBAN constitute a presumption in favor of renewal.

10. Proof guide: Which documents should be collected?

11. Mandatory mediation and litigation process

Process order:

1. Preliminary preparation: Determination of the start date of the rental relationship and whether the five-year period has expired; comparable property research.
2. Notice (for the lessor): Written notification that the rent will be increased, at the latest 30 days before the start of the new rental period.
3. Mediation application: Application to the mediation office at the courthouse located where the immovable property is situated. With the application, the statute of limitations is suspended, and forfeiture periods do not run.
4. Lawsuit: In case of non-agreement, a lawsuit is filed in the Civil Court of Peace, attaching the final report (HCPC Article 4/1-a). The general rule for jurisdiction is the court of the defendant’s domicile (HCPC Article 6); in lawsuits arising from contracts, the court of the place where the contract is to be performed is also optionally competent (HCPC Article 10). Since the place of performance in rental agreements is generally considered to be the location of the rented property, in practice, lawsuits are mostly filed where the immovable property is located. Since a rent determination lawsuit does not concern the substance of the immovable property, the strict jurisdiction rule in HCPC Article 12 does not apply here.
5. Trial: On-site inspection, precedent review, and expert report; followed by an equity assessment.
6. Decision and legal remedies: The rent period from which the decision will be binding is determined according to Article 345 of the TCO.

12. TBK art.345: The thirty-day period and the true function of the notice

One of the most frequently confused points in practice is the belief that the thirty-day period is the period for filing a lawsuit. However, there is no preclusive period or statute of limitations for a rent determination lawsuit; a lawsuit can be filed at any time. The thirty-day period only determines from which rental period the decision will be valid.

• If the lawsuit was filed at least 30 days before the start of the new period: The determined amount is valid from the beginning of that new period.
• If a written notice (ihtarname) was issued within this period: Even if the lawsuit is filed until the end of the subsequent rental period, the decision will still be applied from the beginning of the new period.
• If there is an increase clause in the contract: Without the need for further notice, the decision in a lawsuit filed until the end of the new period will still be valid from the beginning of the period.
• If none of these were done: The decision will be effective for the next rental period; the landlord loses one year’s rent difference.

The absence of an increase rate in the contract or its inclusion with vague expressions like “at the legal rate” is a separate topic of discussion; we examined this issue in detail in our article titled Is an Increase Possible if There is No Increase Rate in the Rental Contract?.

13. Equity (old tenant) discount

When five years have passed, the court does not directly rule on the market value. According to established practice, first the rent that the property would command if re-rented vacant is determined; then, considering that the tenant is an existing tenant, a fair discount is applied to this amount. In practice, this is called the “existing tenant discount”.

In this assessment, two lower limits are considered together:

• The determined rent cannot be lower than the amount found by applying the index (CPI 12-month average) to the last paid rent.
• The determined rent cannot exceed the vacant rental value; the difference is covered by a reasonable discount.

The discount rate is not stipulated in the law; it is determined based on an expert report according to the specific conditions of each case. Therefore, the selection of comparable properties and objections to the expert report directly affect the outcome of the lawsuit.

14. Indivisibility of the claim and prohibition of amendment

Furthermore, in a rent determination lawsuit, only the determination of the rent amount applicable for the relevant period can be requested; eviction or the collection of rent arrears cannot be requested in the same lawsuit. These claims are subjects of separate lawsuits or enforcement proceedings.

15. New owner’s alternative remedy: Eviction under Article 351 of the TCO

A rental price determination lawsuit is not the only tool available to the new owner. The owner who subsequently acquires the property may demand eviction in accordance with Article 351 of the TCO if there is a need for housing or a workplace for themselves, their spouse, their descendants, ascendants, or persons they are legally obliged to support. For this,

• A written notification must be given to the tenant within one month from the date of acquisition,
• A lawsuit must be filed six months after the date of acquisition.
• Alternatively, the new owner may also file a lawsuit within one month starting from the end of the contract term.
• In any case, the need must be real, sincere, and compelling and must persist throughout the litigation.

The procedural rules for this method are very strict; missing the one-month notification period leads to the complete loss of the right. For details: Is Sending a Warning Letter Alone Sufficient for Tenant Eviction?

16. 8 most common mistakes made in practice

1. Believing the new contract “resets” the term. While landlords rely on a new contract date and wait five years, tenants, with the same misconception, do not exercise their rights.
2. Not keeping the old contract. A tenant who cannot meet the burden of proof loses years of accumulated protection.
3. Skipping the mediation stage. The case is dismissed on procedural grounds before entering the merits; leading to a loss of time and fees.
4. Missing the thirty-day window. Even if the case is won, the decision is postponed to the next period; a one-year difference is lost.
5. Stating a low figure in the petition. Since the claim cannot be divided or amended, there is no possibility of increasing it later.
6. Neglecting precedent research. In cases where no precedent is presented, the expert report alone becomes determinative.
7. Relying on an obsolete criterion. Using quotations from the PPI period without adding an update note.
8. Confusing eviction and determination claims. The two claims cannot be combined in the same lawsuit; they are subject to different procedures and timelines.

17. Rent disputes on Istanbul’s Anatolian Side

In recent years, the gap between rental fees and existing contract fees has significantly widened along the line of Tuzla, Pendik, Kartal, Maltepe, Ataşehir, Ümraniye, Sancaktepe, Sultanbeyli, Kadıköy and Gebze and Kocaeli. The industrial and logistics density in the region also makes the determination of comparable rents for workplaces a technical matter: the rental value of two shops on the same street can seriously diverge even with differences in facade and entrance level.

In cases where the real estate has changed hands, the land registry record, sale date, and the tenant’s history of de facto possession must be evaluated together. In such cases, success often depends not so much on the legal justification in the petition, but rather on the quality of the documents collected during the preparation stage.

18. Frequently asked questions

Resources and legislation

• Turkish Code of Obligations No. 6098 (Art. 310, Art. 344, Art. 345, Art. 351) — mevzuat.gov.tr current text · PDF
• Law No. 7161 dated 17.01.2019, Art. 56 (PPI → CPI amendment in TCO Art. 344)
• Law on Mediation in Legal Disputes No. 6325, Art. 18/B — mevzuat.gov.tr
• Code of Civil Procedure No. 6100, Art. 4 (competent court) — mevzuat.gov.tr
• Supreme Court Unification of Jurisprudence Decision dated 18.11.1964 and numbered 2/4 (principle of equity and fairness)
• TUIK — Consumer Price Index twelve-month average change rates: tuik.gov.tr
• Supreme Court and Regional Court of Justice decisions mentioned in the text — UYAP Case Law / Decision Search systems

Legal Warning: This article is for general informational purposes; it does not constitute legal advice or attorney services for a specific case. Each file must be evaluated separately within the framework of its own documents and conditions. The particulars of the decisions mentioned in the text should be confirmed via UYAP before use.
Last updated: July 28, 2026 · 2M Law Firm — Postane Neighborhood. Seher Street. No:18/2 Tuzla/Istanbul