Prior Use Trumps Registration: Both Claims Dismissed, Plaintiff Ordered to Pay TRY 524,697 in Legal Fees — Istanbul 1st IP Court 2026/153

A trademark registration is not an absolute shield. Under Turkish law, a party that can demonstrate prior and continuous use of a sign before the registration date may invoke that prior use against the registered owner — even where the registration is formally valid. Istanbul 1st IP Court's decision 2026/153 illustrates the costly consequences of overlooking this principle before filing suit.

Procedural History

The action was filed in 2017. The plaintiff, the registered owner of a mark used in connection with a real estate development project, claimed that the defendant was using a confusingly similar sign in the same sector and sought: a declaration of infringement; an injunction; access blocking of the defendant's website; and material and moral damages. The defendant counterclaimed for invalidity of the plaintiff's registration.

The first-instance court ruled in 2021. The defendant appealed; in 2023 Istanbul Court of Appeal, 16th Civil Division, dismissed the appeal on the merits. The defendant then appealed to the Court of Cassation: Yargıtay 11th Civil Division reversed the judgment in 2024.

The Key Finding on Remand: Defendant's Prior Use

On remand, the court commissioned a fresh expert report under Art. 266 of the Civil Procedure Code and re-evaluated all evidence. The decisive finding:

As of the plaintiff's trademark registration date, the defendant already held prior use rights over the disputed sign in the relevant field.

This single finding destroyed the plaintiff's case. A party that genuinely and continuously used a sign before another party's registration date may assert that prior use as a defence — the registered owner cannot enforce the mark against them. Since the defendant had prior use, the plaintiff's registration gave it no enforceable rights against the defendant.

Ruling

• Main action (infringement + damages): DISMISSED
• Counterclaim (invalidity): DISMISSED

The simultaneous dismissal of the counterclaim indicates that the registration remains formally valid — it simply cannot be enforced against this particular defendant.

Financial Consequences for the Plaintiff

Takeaway

This case illustrates one of the most serious and avoidable litigation risks in Turkish trademark law: failing to investigate the opponent's use history before filing suit. A registered trademark does not guarantee a win when the defendant can prove earlier use. Before filing an infringement action, counsel should carefully investigate when the defendant first began using the disputed sign, what evidence of that use exists, and whether such prior use predates the plaintiff's registration. In a case involving a sector competitor, that investigation can make the difference between a winning claim and a seven-year, TRY 729,000 loss.