A practical guide to istinaf and cassation in Turkish civil litigation, including deadlines, scope of review, procedural steps, monetary thresholds, and common appeal mistakes.
In Turkish civil litigation, winning at first instance is not always the end of the dispute, and losing at first instance does not necessarily mean the case is over. The Turkish system provides a two-tier review structure for most civil judgments: first, istinaf before the Regional Court of Appeal (Bölge Adliye Mahkemesi or BAM), and second, where legally available, cassation before the Court of Cassation (Yargıtay). Understanding the difference between these two remedies is essential because they do not serve the same function, do not examine the case in the same way, and do not carry the same procedural consequences. HMK Article 341 governs appealable first-instance decisions, while Articles 361 and following regulate cassation against appeal-court decisions.
For foreign investors, companies, individuals, and even experienced litigants, the appeal system in Turkey can be deceptively technical. Missing the filing window, misreading the monetary threshold, submitting an unfocused petition, or confusing the scope of istinaf with the narrower function of cassation can significantly weaken a case. The appeal process in Turkey is highly procedural: deadlines are short, formal requirements matter, and the legal effect of each stage must be assessed before taking the next step.
This guide explains the appeal structure in Turkish civil litigation in practical terms. It covers what istinaf is, what cassation is, which decisions can be reviewed, how the petitions are filed, how the review is conducted, what happens after reversal, and what mistakes parties should avoid if they want to preserve their rights effectively under the Turkish Code of Civil Procedure.
The Two-Tier Appeal Structure in Turkish Civil Cases
The Turkish civil justice system generally operates with three decision-making levels in contentious civil disputes: the first-instance court, the Regional Court of Appeal (istinaf), and, in cases that meet statutory requirements, the Court of Cassation (temyiz). Istinaf is the first ordinary appeal. It is directed against eligible first-instance judgments and certain interim-relief decisions. Cassation comes after the Regional Court of Appeal and is available only for decisions that remain open to review under HMK Articles 361 and 362.
This structure matters because the two remedies are not interchangeable. Istinaf is a broader form of review. The BAM can examine both procedural and substantive issues, may hold a hearing, may complete certain missing steps, may correct the judgment, and in some cases may issue a new merits decision. Cassation, by contrast, is a review by Yargıtay of whether the BAM decision complies with law; it is primarily a legal-control mechanism, not a second full factual retrial. That difference should shape appeal strategy from the moment the first judgment is served.
What Is Istinaf in Turkish Civil Litigation?
Under HMK Article 341, first-instance final judgments are appealable to the Regional Court of Appeal. The same article also allows istinaf against decisions rejecting requests for interim injunctions or interim attachments, as well as against certain decisions rendered upon objection to such relief. The current text of Article 341 also reflects the 2020 amendment that reorganized the wording of appealable interim-relief decisions.
Istinaf is not merely a symbolic review. It is a real corrective stage in which the BAM examines whether the first-instance court handled the case properly in law, procedure, and, to a meaningful extent, in its evaluation of the record. That is why Turkish practitioners often treat istinaf as the most important appellate stage in civil litigation. In many disputes, the most realistic chance of reversing an unfavorable judgment lies at the BAM level rather than later at Yargıtay.
Another important point is that some first-instance judgments are final because of statutory monetary thresholds or subject-matter exclusions. Current HMK practice does not use a fixed static number. Additional Article 1 provides that the monetary thresholds in Articles 341, 362, and 369 are increased every calendar year using the revaluation rate announced under the Tax Procedure Law, and—following the 2025 legislative amendment—the applicable threshold for Articles 341, 362, and 369 is determined according to the date the lawsuit was filed, not the date the judgment was issued. The Revenue Administration announced the 2025 revaluation rate as 25.49%, which is the basis used for 2026 annual threshold calculations.
That filing-date rule is practically very important. A party considering appeal can no longer assume that the threshold will be measured by the judgment date. The correct question is: what was the applicable threshold on the date the case was filed? For law offices managing older files, this change can affect whether a judgment is appealable at all.
Which Decisions Can Be Appealed by Istinaf?
As a rule, first-instance final decisions may be challenged before BAM. In addition, Article 341 specifically includes certain interim injunction and interim attachment rulings. The same framework also preserves appealability in moral-damages cases regardless of amount, as recognized in the Constitutional Court’s explanation of Article 341.
However, parties must still verify whether the case falls below the applicable monetary finality threshold or within a category excluded from further review by law. Turkish appealability rules are not determined by the title of the case alone. They depend on the nature of the decision, the amount in dispute where relevant, and the statutory regime applicable on the filing date of the lawsuit.
Time Limit for Filing Istinaf
HMK Article 345 states clearly that the period for filing istinaf is two weeks, starting from proper service of the judgment on each party, unless a special statute provides otherwise. This is a short and strictly applied deadline. The Ministry of Justice’s 2025 activity report also notes that appeal periods, including istinaf and cassation, have been standardized as two-week periods in the relevant framework to create uniformity.
In practice, this means the clock starts from lawful notification, not from when the client forwards the decision internally, and not from when counsel happens to read it. In Turkish litigation, appeal timing is a serious risk area, especially when electronic notification systems are involved. A party that hesitates while “evaluating options” may find that the appeal window has already closed.
How to File an Istinaf Petition
HMK Article 342 regulates the content of the istinaf petition. It must identify the parties, representatives if any, the issuing court, the date and number of the judgment, the date of service, a summary of the decision, the appeal grounds and reasoning, the relief sought, and the signature of the applicant or counsel. The petition must be filed in writing and accompanied by copies for the opposing side.
At the same time, Turkish law follows a functional approach to avoid overly formalistic rejection. Article 342/3 provides that if the petition sufficiently identifies the appellant, includes a signature, and makes the challenged judgment sufficiently clear, it is not rejected merely because other details are incomplete; the BAM proceeds with the necessary review within the framework of Article 355. This is useful, but it should never be treated as permission to draft carelessly. A weak petition may survive formal scrutiny and still fail strategically.
Under Article 343, the istinaf petition may be submitted either to the court that rendered the judgment or to another local court, which records the filing and transmits it onward. Article 344 further requires payment of the relevant appeal fee and service expenses; if these are missing or incomplete, the court grants a one-week final period, and if the deficiency is not cured, the appeal is deemed not filed.
This point often causes avoidable losses. In Turkey, an appeal is not protected merely because counsel “prepared the petition on time.” Fees and procedural filing requirements matter. If the costs are not paid or completed within the final period, a potentially strong appeal may never reach substantive review.
Response Petition and Cross-Appeal in Istinaf
The istinaf petition is served on the opposing party, and under Article 347 the other side may file a response within two weeks. That response is not only defensive. Article 348 allows a form of cross-appeal by response petition: even a party that no longer has an independent right to appeal, or has missed its own appeal deadline, may still challenge the judgment through the response if the other side filed a timely istinaf.
This is a strategically important rule. A party that is generally satisfied with the judgment but objects to one part of it should always assess whether a cross-appeal is necessary once the other side appeals. At the same time, Article 348 makes that cross-appeal dependent on the principal appeal. If the main appeal is withdrawn or rejected without a merits review, the joinder-based appeal falls with it.
Scope of Review Before the Regional Court of Appeal
HMK Article 355 provides the key rule on the scope of istinaf review: the BAM examines the case within the limits of the grounds stated in the appeal petition, but it must also consider public-order issues ex officio. This means istinaf is neither fully unrestricted nor purely formal. A well-drafted petition matters because the BAM is generally guided by the specific reasons articulated by the appellant.
This is why generic appeal language is dangerous. Simply saying that “the judgment is unlawful” or “the evidence was wrongly assessed” is usually not enough. Effective istinaf advocacy in Turkey identifies the exact procedural or substantive errors, explains why the first-instance court’s reasoning is flawed, and ties those points to the record. The Regional Court of Appeal is a powerful forum, but it still reviews what the party actually presents.
Hearing, New Evidence, and Limits at the Istinaf Stage
HMK draws a careful line between cases that can be decided on the file and those requiring a hearing. Article 353 lists situations in which BAM may act without a hearing, including certain jurisdictional or procedural defects, cases where no merits review is possible, or cases where the court can reject the appeal on the merits or correct the judgment without reopening a full hearing. Article 356 states that outside the scenarios listed in Article 353, the review is conducted with a hearing.
This makes istinaf materially different from cassation. The BAM is not confined to purely abstract legal review. It can engage more directly with case management and, in appropriate circumstances, can complete limited deficiencies and issue a new decision on the merits. That is one reason why Turkish civil practitioners usually devote major effort to the BAM petition.
But istinaf is still not a blank second trial. Article 357 prohibits counterclaims, intervention requests, amendment of the action by ıslah, and—subject to narrow exceptions—new claims, new defenses, and new evidence that were not properly raised below. Evidence that was duly offered in first instance but not examined, or evidence that could not be presented because of force majeure, may still be considered. This means the appeal court can correct many first-instance errors, but it does not allow parties to rebuild the entire case from scratch.
Possible Outcomes of Istinaf Review
HMK Article 353 is central to understanding what BAM can actually do. After its preliminary review under Article 352, the BAM may reject the appeal on threshold grounds such as lateness, finality of the judgment, failure to meet appeal conditions, or complete absence of grounds. If the file is procedurally complete, BAM may: set aside the judgment and send the file back for retrial in certain serious procedural situations; reject the appeal on the merits; correct the judgment and render a new merits decision where no retrial is needed; or complete certain deficiencies and then decide again on the merits.
That last category is especially important. Turkish istinaf is not only a yes-or-no checkpoint. It can produce a new operative judgment. Therefore, parties should not assume that the Regional Court of Appeal will merely approve or reject what the first-instance judge did. In suitable cases, BAM can reshape the outcome directly.
What Is Cassation (Temyiz) in Turkish Civil Litigation?
Cassation is the next stage after istinaf. Under the current version of HMK Article 361, appealable final decisions of the Regional Court of Appeal’s civil chambers, as well as decisions rendered on applications to set aside arbitral awards, may be challenged before Yargıtay within two weeks from service. The party that prevailed below may also file cassation if it has a legal interest in doing so.
Cassation is not automatically available in every case. HMK Article 362 excludes certain BAM decisions from Yargıtay review, including decisions under the applicable monetary finality threshold and several subject-matter categories such as many disputes within the sphere of the civil peace courts, non-contentious matters, certain venue and assignment rulings, and interim legal protection decisions. Article 362 must therefore be checked carefully before preparing a cassation petition.
The practical consequence is straightforward: not every case that reaches BAM can also go to Yargıtay. In Turkish litigation, the Regional Court of Appeal is often the final merits court. That is why litigants must avoid treating istinaf as a mere warm-up round before the “real” appeal. In a large number of civil files, istinaf is the decisive appellate battlefield.
How to File a Cassation Petition
HMK Article 364 sets out the required contents of the cassation petition. It must identify the parties and representatives, specify the BAM chamber and decision being challenged, state the service date, summarize the decision, provide the cassation grounds and reasoning, indicate any request for a hearing, and bear the appellant’s signature. As with istinaf, Article 364/3 adopts a pragmatic approach: if the petition clearly identifies the appellant and the challenged judgment, the absence of some other details does not automatically lead to rejection.
Under Article 365, the cassation petition may be filed with the BAM chamber that issued the decision, with the first-instance court that gave judgment after a remand, or with the BAM or first-instance court where the appellant is located. Article 366 applies several istinaf provisions by analogy in cassation, including filing, notification, and rejection rules.
Scope of Review at the Yargıtay Stage
One of the most significant doctrinal differences between istinaf and cassation lies in the scope of review. Under Article 355, BAM review is generally limited to the grounds stated in the appeal petition, subject to public order. By contrast, HMK Article 369 states that Yargıtay is not bound by the cassation grounds advanced by the parties and may also review other issues that it finds clearly contrary to law.
This does not turn cassation into a new fact-finding stage. Rather, it shows that Yargıtay’s role is one of legal supervision. Article 369 also provides that the review is generally conducted on the file, although a hearing may be held in specified categories of cases or where the dispute exceeds the applicable monetary threshold and one of the parties requests a hearing in the cassation or response petition. Since the monetary threshold for Yargıtay hearings is also adjusted annually under Additional Article 1, practitioners must verify the applicable figure by reference to the filing date of the lawsuit.
What Can Yargıtay Do?
HMK Article 370 allows Yargıtay to affirm a judgment, including by correcting legal reasoning or certain obvious errors without sending the file back, where a new trial is unnecessary. Article 371 lists the main grounds for reversal: misapplication of law or contract, lack of procedural conditions, wrongful refusal of evidence relied upon for proof, and procedural errors or deficiencies affecting the judgment.
This framework reflects the essential function of cassation in Turkey. Yargıtay does not normally re-try the case. It checks whether the law was applied correctly, whether the court respected procedural guarantees, and whether the judgment is legally sustainable. For that reason, a cassation petition should focus on legal error, reviewable procedural irregularity, and the way those errors influenced the outcome. A party that simply repeats its factual narrative from first instance usually misses the point of cassation review.
Does Appeal or Cassation Stop Enforcement?
As a rule, no. HMK Article 350 states that filing istinaf does not stop enforcement, and Article 367 says the same for cassation. Both provisions preserve the mechanism of stay of execution under Article 36 of the Enforcement and Bankruptcy Law, and both also state that alimony judgments cannot be stayed through that mechanism. At the same time, judgments in matters such as personal status, family law, and real rights over immovable property are not enforceable until they become final.
This is one of the most misunderstood parts of Turkish appeal practice. Many litigants assume that filing an appeal automatically freezes the effect of the judgment. In ordinary patrimonial disputes, that assumption is often wrong. Strategic planning therefore requires a separate enforcement analysis in parallel with the appeal.
What Happens After Reversal?
HMK Article 373 explains the post-reversal path. If Yargıtay reverses a BAM decision that had dismissed the appeal on the merits, the BAM decision is lifted and the file is sent to the first-instance court or another appropriate first-instance court. If Yargıtay reverses a BAM decision that had corrected the judgment or rendered a new merits decision, the file is sent back to the BAM that rendered the decision or another suitable BAM. If the lower court or BAM resists the reversal, further review is conducted by the Yargıtay General Assembly of Civil Chambers (Hukuk Genel Kurulu).
This post-reversal architecture matters because not every reversal returns the file to the same place. The route depends on what the BAM did in the first place. For that reason, an effective appeal strategy in Turkey must always look one step ahead: not only whether to appeal, but what kind of appellate outcome is realistically sought and where the file will go if the challenge succeeds.
Common Mistakes in Turkish Appeal Practice
The most common mistake is missing the two-week filing period. The second is filing a petition that is technically timely but substantively thin. The third is overlooking the annual monetary-threshold regime and the current rule that ties the threshold to the date of filing of the lawsuit. The fourth is confusing istinaf with cassation and drafting both petitions in the same style, even though BAM and Yargıtay review different things in different ways.
Another major mistake is ignoring the difference between a case that can still be factually and procedurally corrected at the BAM stage and a case that has reached the narrower legal-review stage before Yargıtay. At the BAM level, a party should focus on trial-level procedural errors, evidentiary gaps, and misassessment of the file within the limits of Article 355. At the Yargıtay level, the emphasis should shift to legal misapplication, reviewable procedural illegality, and reversible defects under Articles 369 to 371.
Conclusion
The appeal system in Turkish civil litigation is structured, layered, and highly technical. Istinaf before the Regional Court of Appeal is the broad and often decisive review stage, where the case can still be meaningfully corrected, reconsidered, or even re-decided on the merits. Cassation before Yargıtay is a more focused legal review, available only where the law allows it and shaped by different standards and consequences.
For that reason, successful appellate practice in Turkey depends on more than simply disagreeing with the judgment. It requires checking appealability, calculating the correct filing window, applying the correct monetary-threshold rule, drafting stage-appropriate grounds, and aligning procedural tactics with the actual function of the reviewing court. In Turkish civil procedure, the difference between a routine appeal and an effective one is usually found in that level of precision.
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