Appealing a Tenfiz Decision in Turkiye: Istinaf and Temyiz

A first-instance decision on a tenfiz action, whether it grants or refuses enforcement of a foreign judgment, can be appealed to the regional court of appeal (istinaf) and, if the applicable conditions are satisfied, further challenged before the Court of Cassation (temyiz). The decision is not final and enforceable in the ordinary sense until these avenues are exhausted or the applicable deadlines pass without an appeal.

Because a tenfiz decision determines whether a foreign judgment will have legal effect in Türkiye, either side has a strong interest in the outcome and, correspondingly, a right to seek appellate review. Understanding the appellate structure helps both claimants and debtors plan for the realistic total duration of the enforcement process, not just the first-instance stage.

Article 55 of Law No. 5718 on Private International Law and International Civil Procedure (MOHUK) confirms that tenfiz decisions are subject to the ordinary appellate remedies available under Turkish civil procedure. The Code of Civil Procedure No. 6100 governs the istinaf appeal before the regional court of appeal and, where the case meets the statutory threshold and criteria for further review, the temyiz appeal before the Court of Cassation.

Regional courts of appeal reviewing tenfiz decisions examine whether the first-instance court correctly applied the statutory conditions under Article 54, such as reciprocity, jurisdiction, public policy and due process, as well as whether procedural requirements were properly followed. The Court of Cassation, where an appeal reaches it, similarly focuses on legal questions relevant to the enforcement conditions, rather than reopening the substantive merits of the foreign judgment itself.

Some commentators have questioned whether a case that turns on a narrow set of statutory conditions, rather than the underlying merits, should be entitled to the same multi-tier appellate process as ordinary civil litigation, given the added time this adds to enforcement. Others emphasise that because enforcement produces significant consequences for both parties, full appellate review remains justified and consistent with general due process guarantees under Turkish procedural law.

A party wishing to appeal must do so within the applicable procedural deadline following notification of the reasoned first-instance decision, and should frame the appeal around the specific statutory conditions that are disputed, rather than raising generalised objections to the foreign judgment's merits, which fall outside the scope of tenfiz review.

Appeals against a tenfiz decision follow the general deadlines applicable to civil appeals under the Code of Civil Procedure No. 6100, requiring a party to file the istinaf appeal within a limited period after notification of the reasoned decision, with any subsequent temyiz appeal following a similarly bounded window after the regional court of appeal's ruling.

The relevant regional court of appeal reviews the first-instance tenfiz decision, and the Court of Cassation serves as the final domestic instance where the conditions for such review are met.

An appeal file should include the reasoned first-instance decision, the notification record establishing when the deadline began to run, and a clearly structured appellate petition addressing the specific legal grounds under challenge, supported by the same category of evidence relevant to those grounds, such as reciprocity or service documentation.

A frequent mistake is treating the appeal as an opportunity to reargue the underlying foreign dispute, which the appellate courts will not entertain in a tenfiz case. Missing the appeal deadline because notification dates were not tracked carefully is another recurring issue. Parties sometimes also assume enforcement can proceed immediately once a first-instance decision is issued, without accounting for the suspensive effect of a timely appeal.

Both claimants and debtors should plan for the realistic possibility of an appeal from the outset of a tenfiz case, rather than treating the first-instance hearing as the final word. Careful tracking of notification dates and a disciplined focus on the statutory grounds for enforcement, rather than the foreign judgment's underlying merits, gives the strongest position on appeal.