How the Turkish Trademark Opposition Process Works — YİDK, Administrative Court and Court of Cassation

In the trademark registration process, opposition can arrive at two points: during bulletin publication (third-party opposition) and within 5 years after registration (invalidity action). This article summarises both processes, defence strategies and Court of Cassation case law.

Third-party opposition

Window: 2-month publication period from bulletin publication.

Who may oppose?

• Holders of earlier registered marks
• Well-known mark holders
• Holders of prior-use rights
• Persons demonstrating a legitimate interest

Contents of an opposition: likelihood-of-confusion argument, earlier-registration evidence, sector research, prior-use documentation.

TÜRKPATENT response: the opposition is served on you within 1 month; you submit your defence within 1 month.

YİDK decision: the Re-Examination and Evaluation Board accepts or rejects the opposition. Average duration 6–9 months.

Invalidity action

Window: 5 years from registration.

Court: Intellectual and Industrial Property Civil Courts (Ankara, İstanbul, İzmir, Adana, Bursa, Konya, Trabzon, Kayseri, Antalya, Diyarbakır).

Grounds:

• SMK art. 5 (absolute grounds)
• SMK art. 6 (relative grounds)
• Bad-faith registration
• Well-known mark rights

Process: complaint → answer → expert report → judgment. Average 18–30 months.

Settled doctrine of the Court of Cassation 11th Civil Chamber — likelihood of confusion

Likelihood of confusion is assessed under four criteria considered together:

1. Similarity of the signs (visual, phonetic, conceptual)
2. Similarity of goods/services
3. Distinctiveness of the earlier mark
4. Average consumer attention level

In a luxury-goods category the consumer attention level is high; in food retail it is low. This level significantly influences the outcome.

Prior-use right (SMK art. 6/3)

Continuous good-faith use prior to registration creates a limited right. Evidence:

• Invoices
• Trade-fair records
• Web archive (Wayback Machine)
• Social-media history
• Old catalogues and brochures

The Court of Cassation is strict in seeking historical continuity and geographic scope of this evidence.

Anonymised case

A well-known İstanbul brand opposed a Kayseri food client's mark. The product categories differed (cheese vs charcuterie) but the class overlapped. Through the YİDK and administrative-court process, the file we built on sector differentiation, consumer attention level and the client's 11 years of prior-use evidence was decided against the opposition 26 months later — i.e. our client's registration was preserved.

— Salih Aksebzeci, from a 2022–2024 file (anonymised)

Defence strategy

Early stage: collect all evidence — do not delay. At Asil we advise clients to maintain a "trademark-use file": invoices, catalogues, web archive, fair documentation kept on an annual basis.

Middle stage: sector research and expert reports. Likelihood of confusion is assessed by court-appointed experts.

Final stage: Court of Cassation appeal. The legal integrity of the decision is examined; shifts in case law are applied.

Sources

1. SMK No. 6769 art. 18 (absolute grounds), arts. 25-29 (invalidity)
2. Court of Cassation 11th Civil Chamber likelihood-of-confusion case law

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Author: Salih Aksebzeci · TÜRKPATENT Agent Registry No. 188 · Published: 2026-05-07