One of the most distinctive yet often overlooked features of Turkish trademark practice is the doctrine of acquired rights. Although neither the former Decree Law No. 556 nor the current Industrial Property Code No. 6769 expressly regulates the concept, it has become firmly entrenched through judicial and administrative practice.

For trademark owners, the doctrine can be a valuable tool. It allows businesses that have built a portfolio of marks around a common element to register new variations of their branding strategy even where a conventional likelihood of confusion analysis might otherwise produce a different result. However, recent decisions of the Turkish Court of Cassation show that acquired rights are being applied increasingly cautiously, and not every trademark family will qualify for protection.

The Rationale Behind Acquired Rights

The concept of acquired rights is rooted in the principles of legal certainty and legitimate expectations, both of which derive from the broader constitutional principle of the rule of law.

In today's commercial environment, consumer preferences and market trends evolve rapidly. Businesses often need to modernize their visual identities, introduce updated logos, or develop new brand extensions while preserving consumer recognition of their existing brands. Turkish courts have therefore long accepted that trademark owners should, under certain circumstances, be able to develop and renew their branding strategies without losing the protection associated with their established market position.

The Court of Cassation recently reaffirmed this approach in its decision numbered 2024/4407 E., 2025/3094 K., emphasizing that legal certainty forms an integral part of the rule of law. According to the Court, allowing the proprietor of a long-standing trademark to register a renewed version of that trademark may be regarded as a natural consequence of protecting legitimate expectations.

At the same time, the Court stressed that acquired rights constitute an exception rather than a general rule and may arise only where specific conditions are cumulatively satisfied.

Trademark Families and the Basis of Acquired Rights

Acquired rights most commonly arise in connection with trademark families (or series trademarks).

According to the Turkish Patent and Trademark Office's Trademark Examination Guideline, a trademark family may exist where the same word element is repeatedly combined with different graphical features, or where a common prefix, suffix, or core element is systematically used across multiple registrations. The decisive consideration is whether consumers would perceive the later trademark as belonging to the same commercial source as the earlier trademarks.

For example, a business that owns and actively uses several trademarks built around a common distinctive element may seek to register an additional variation incorporating the same dominant component. In such circumstances, the owner may argue that its earlier registrations and market presence have created an acquired right supporting the new application.

Genuine Use: The Cornerstone of Acquired Rights

Recent case law demonstrates that genuine use has become one of the most important requirements for establishing acquired rights.

Turkish courts consistently reject the notion that acquired rights can arise merely from the existence of a registration. Instead, the earlier trademark must have achieved a meaningful commercial presence capable of creating market recognition.

The Court of Cassation has held that trademarks registered only one year before the disputed application could not serve as the basis for acquired rights because they had not yet generated sufficient commercial impact. Similarly, the Court repeatedly emphasizes that use must be active, commercial in nature, and capable of producing market effects before the filing date of the later application.

This approach has become particularly significant as non-use challenges gain prominence in Turkish trademark practice. As trademark owners become increasingly exposed to use-based attacks, demonstrating genuine use is likely to remain a critical component of any acquired rights claim.

Acquired Rights Protect Continuity, Not Expansion

Another recurring theme in recent decisions is that acquired rights cannot be used as a mechanism for unrestricted brand expansion.

Trademark proprietors sometimes assume that once a trademark family has been established, protection can automatically extend to new goods and services. Turkish courts have consistently rejected this view.

In several cases, the courts refused to recognize acquired rights where applicants sought protection for goods or services that had not previously been covered by their earlier registrations. According to the prevailing approach, acquired rights are designed to preserve continuity within an existing commercial sphere rather than to create protection in entirely new sectors.

For multinational brand owners and businesses pursuing portfolio expansion strategies, this serves as an important reminder that trademark family arguments are most persuasive when they remain closely connected to established commercial activities.

Acquired Rights Cannot Override Third-Party Rights

The doctrine is also subject to an important limitation: it cannot justify encroachment upon the rights of third parties.

Turkish courts consistently hold that acquired rights cannot be invoked where a new application creates a fresh conflict with an earlier third-party trademark. In other words, the doctrine protects an existing legal position; it does not legitimize a gradual movement toward another proprietor's trademark.

This limitation reflects a fundamental principle of Turkish trademark law. While legal certainty should protect legitimate expectations, it should not do so at the expense of fair competition or the rights of other trademark owners.

Consequently, even a well-established trademark family may fail to benefit from acquired rights if the later application introduces elements that increase the likelihood of confusion with an earlier third-party trademark.

The Growing Importance of the Five-Year Period

One of the most notable developments in recent years concerns the legal stability of the root trademark.

The Court of Cassation has suggested that a trademark which remains vulnerable to invalidation may not provide a sufficiently secure basis for acquired rights. Several recent decisions indicate that trademarks registered for less than five years may still be considered legally unstable due to their exposure to invalidity actions and, therefore, incapable of creating the legitimate expectation required by the doctrine.

Although Turkish legislation does not establish an explicit five-year threshold for acquired rights, recent case law suggests that the age and stability of the earlier trademark are becoming increasingly relevant factors in practice.

If this trend continues, trademark owners may face a heavier evidentiary burden when relying on relatively recent registrations to support trademark family arguments.

The Impact of Pending Legal Challenges

Another increasingly important consideration in Turkish practice concerns the legal An increasingly important question is whether a trademark that has been registered for more than five years can support an acquired rights claim while simultaneously being challenged through legal or administrative proceedings.

Emerging views suggest that the answer may be negative.

Even where a trademark has exceeded the five-year period and is no longer exposed to ordinary invalidity claims, the existence of an ongoing legal dispute, such as a non-use cancellation action or another challenge affecting its validity, may undermine its suitability as the foundation for acquired rights.

The rationale is straightforward. Acquired rights are based on legal certainty and legitimate expectations. Where the validity, ownership, or continued protection of the earlier trademark remains actively contested, the degree of legal certainty required to justify an acquired rights claim may be lacking.

This issue has become particularly relevant since the introduction of administrative non-use cancellation proceedings before the Turkish Patent and Trademark Office. As cancellation actions become increasingly common, trademark owners may face growing arguments that a contested root trademark cannot serve as a reliable basis for acquired rights, regardless of how long it has been registered.

Looking Ahead

Acquired rights remain one of the most distinctive and potentially powerful doctrines in Turkish trademark law. Yet recent judicial practice demonstrates a clear effort to keep the doctrine within carefully defined boundaries.

The Court of Cassation appears committed to balancing two competing objectives: protecting the legitimate expectations of established trademark owners while preventing acquired rights from becoming a shortcut around traditional likelihood of confusion principles.

For trademark owners, the practical message is clear. Successful reliance on acquired rights will increasingly depend on demonstrating:

• Genuine and continuous use of the earlier trademark;
• Consistency across the trademark family;
• Respect for third-party rights;
• Commercial continuity rather than expansion into new sectors; and
• A sufficiently stable and uncontested legal foundation for the earlier trademark.

As Turkish trademark practice continues to evolve, acquired rights are likely to remain a frequently litigated issue and an increasingly important consideration in long-term trademark portfolio management.