Criminal Appeals in Turkey: İstinaf, Temyiz & AYM Guide

Criminal appeals in Turkey have become one of the most consequential procedural battlegrounds for foreign defendants, multinational executives, and high-net-worth individuals confronting criminal exposure within Turkish jurisdiction. From a fake-invoice conviction under VUK 359 to a fraud sentence under TCK 158, the distance between an unfavourable first-instance verdict and a final, enforceable sentence is governed by a tightly choreographed appellate architecture: İstinaf at the Regional Court of Justice (Bölge Adliye Mahkemesi), Temyiz at the Court of Cassation (Yargıtay), an Individual Application to the Constitutional Court (Anayasa Mahkemesi), and — when domestic remedies are exhausted — an application to the European Court of Human Rights in Strasbourg. Missing a single two-week window can make the judgment final and lock in a sentence that destroys a career, dismantles a corporate structure, and triggers cross-border consequences across asset registries, banking relationships, and immigration files.

For foreign principals operating in Turkey, the appellate path is not a back-office formality — it is a central risk-mitigation instrument once a conviction is rendered at first instance. Foreign defendants can face language barriers and an evidentiary record built without the cross-border framing that an international standard of defence demands. Istanbul Attorneys advises foreign defendants in English at the appellate stage: preserving procedural objections on the trial record, drafting istinaf and temyiz grounds, and, where the admissibility conditions are met, carrying the matter to the Constitutional Court or the European Court of Human Rights.

Key Takeaways

• The İstinaf appeal window is two weeks from service of the judgment together with its reasoning, under Article 273(1) of CMK No. 5271 as amended by Law No. 7499 of 2 March 2024; a late appeal is rejected (CMK 276), and only a timely appeal prevents the judgment from becoming final (CMK 275(1)).

• Temyiz lies against Regional Court judgments, but CMK 286(2) excludes, among others, decisions that dismiss an appeal against a first-instance prison sentence of five years or less or that do not increase such a sentence; CMK 286(3) reopens Temyiz for listed offences. Temyiz can rest only on the judgment being unlawful (CMK 288), not on a rehearing of facts.

• A Constitutional Court Individual Application (bireysel başvuru) must be filed within 30 days of exhausting the available remedies (Law No. 6216, Article 47(5)); if a violation arising from a court decision is found, the file is sent back for retrial, or compensation may be awarded where a retrial would serve no legal interest (Article 50(2)).

• The European Court of Human Rights remains available for applications filed within four months of the final domestic decision under Article 35(1) of the Convention.

• Appellate work begins at the trial stage: under CMK 222, whether the hearing was conducted in accordance with the law can be proved only by the hearing record, so objections need to be entered in the minutes.

The Turkish Criminal Appeals Architecture

The Turkish criminal-appeals architecture rests on a four-tier review system designed to test both the factual reconstruction of the offence and the legal qualification adopted by the trial court. Codified principally in the Criminal Procedure Code (CMK) No. 5271, the framework provides one ordinary appeal that re-examines facts and law, a cassation-style review of legal compliance, and two extraordinary remedies that test the conviction against constitutional and Convention rights.

First-Instance Conviction and Why Trial Strategy Determines Appeal

The trial record itself shapes the appeal. Every procedural objection, every motion to exclude evidence, every challenge to expert reports, and every request for an interpreter should be entered into the hearing minutes (tutanak). Under CMK 222, how the hearing was conducted, and whether it followed the procedure required by law, can be proved only by the minutes, and the minutes can be challenged only by an allegation of forgery. An objection raised orally but not recorded is therefore difficult to rely on at the appellate stage, which is why someone on the defence side should follow the minutes while the hearing is running in Heavy Penal cases involving foreign defendants.

Three Domestic Tiers Plus Strasbourg

Once a conviction is entered at first instance, three formal review tiers become available within the Turkish system: ordinary appeal at İstinaf, cassation at Temyiz, and constitutional review at the Anayasa Mahkemesi. A fourth, supranational tier — the European Court of Human Rights — remains accessible after domestic remedies are exhausted. Each tier has distinct admissibility criteria, scope of review, and remedial powers that need to be assessed as soon as the first-instance verdict is delivered.

İstinaf — Regional Court of Justice (Bölge Adliye Mahkemesi)

The Two-Week Filing Window and Procedural Requirements

Under Article 273(1) of CMK No. 5271, as amended by Law No. 7499 of 2 March 2024, the appeal to the Regional Court of Justice must be lodged within two weeks of the date on which the judgment is served together with its reasoning (gerekçeli karar), by a petition to the court that gave the judgment or by a declaration to the court clerk that is recorded in minutes. A detained defendant can also lodge it through the prison administration (CMK 263). The period cannot be extended; a person who missed it without fault can apply for restoration of time (eski hâle getirme) within two weeks of the obstacle ending, and a person who was not informed of the right of appeal is treated as not at fault (CMK 40–41). For the defendant, failure to state grounds in the petition does not prevent review (CMK 273(4)), whereas the prosecutor must set out the grounds with reasons (CMK 273(5)); stating each error in writing is nonetheless the way to direct the court's attention to it.

Scope of Review — Both Fact and Law

Unlike cassation review, the Regional Court of Justice examines the file and the evidence (CMK 280(1)). Where it neither dismisses the appeal nor sends the case back, it holds a new hearing, can decide to hear witnesses and experts and to conduct an inspection (CMK 280(1)(g), 281(2)), and at the end either dismisses the appeal or sets aside the first-instance judgment and gives a new one (CMK 280(2)). This is the stage at which a foreign defendant can ask the court to examine the evidence again, supported by translated documents, expert reports, and witnesses. Counsel must approach the istinaf brief as a structured re-litigation rather than a perfunctory recital of trial-court errors.

Possible Outcomes

The court may dismiss the appeal on the merits, in certain cases correcting the error itself (CMK 280(1)(a)–(d)); set aside the judgment and send the case back to a first-instance court in the situations listed in CMK 280(1)(e)–(f), such as the absolute grounds of unlawfulness in CMK 289; or hold a hearing and give a new judgment, which can be an acquittal or a different sentence (CMK 280(2)). Any change, even a partial one, can affect asset seizures, professional disqualifications, and immigration status. Where only the defendant, or the prosecutor in the defendant's favour, appealed, the new judgment cannot impose a heavier sentence than the first (CMK 283(1)).

Common questions about criminal defence in Turkey

Can a foreign national file a criminal appeal from outside Turkey?

Yes. A lawyer can lodge the appeal on the defendant's behalf, provided it is not against the defendant's express wishes (CMK 261), and physical presence in Turkey is not required for filing. If the Regional Court holds a hearing and the duly summoned defendant does not attend, it can finish the case in the defendant's absence, but it must hear the defendant before imposing a heavier sentence than the first-instance court (CMK 282(1)(f)). Non-resident defendants should remain in close contact with counsel so that procedural decisions can be taken in time.

What happens to my sentence while the appeal is pending?

A timely İstinaf appeal prevents the judgment from becoming final (CMK 275(1)), and a conviction cannot be executed until it is final (Law No. 5275, Article 4(1)). Pretrial detention, where ordered, is a separate protective measure with its own rules. Once the conviction becomes final at the highest accessible domestic tier, execution proceeds — which is why the integrity of the appellate sequence is decisive for liberty and asset preservation.

Do constitutional and ECHR applications stop enforcement of the sentence?

Not by themselves. Both are brought after the domestic remedies have been exhausted, against a judgment that is already final, and filing does not reopen that finality. During the examination on the merits, the Constitutional Court's sections may order, of their own motion or on request, the measures they consider necessary to protect the applicant's fundamental rights (tedbir kararı); if they do, the decision on the merits must be given within six months, otherwise the measure lapses (Law No. 6216, Article 49(5)).

Can a sentence be increased on appeal?

Only if an appeal was also lodged against the defendant. Where the İstinaf appeal was lodged only in the defendant's favour, the new judgment cannot impose a heavier sentence than the first (CMK 283(1)); the same protection applies after a Court of Cassation reversal where the judgment was appealed only by the defendant, or in the defendant's favour by the prosecutor or the persons listed in CMK 262 (CMK 307(5)). Where the prosecutor or the intervening party (katılan) has appealed against the defendant, the sentence can be increased. Appellate strategy must therefore weigh the realistic prospect of relief against that risk.

How do I choose between filing only İstinaf and pursuing the full appellate ladder?

This is a strategic decision driven by the specific grounds available, the sentence imposed, the collateral consequences (asset seizures, immigration restrictions, professional licensing), and the client's appetite for protracted proceedings. Whether Temyiz is available at all depends on the limits in CMK 286. Counsel should map the available grounds and remedies at each tier before recommending a path.

Does my foreign citizenship affect my appellate rights in Turkey?

No. Nationality is not a condition for any appeal route: CMK 260(1) opens legal remedies to the prosecutor, the suspect or defendant, and the victim without distinction. A defendant who does not speak Turkish well enough is entitled to a court-appointed interpreter (CMK 202(1)), and a foreign national's arrest, custody or detention is notified to their consulate unless they object in writing (CMK 95(2), 107(3)). Citizenship does affect collateral matters: under TCK 59, a foreign national sentenced to imprisonment is reported to the Ministry of Interior for assessment of deportation once supervised release or conditional release is granted, and in any case once the sentence has been served, so criminal and immigration questions should be considered together.

This guide is general information on Turkish law, not legal advice on your own matter. Rules and practice change; check the position before you act.