Trademark Dilution (Intended for a Non-Legal Audience)

Updated: September 2025

1. What is trademark dilution?

Trademark dilution occurs when someone uses a trademark in a manner that is likely to weaken the distinctiveness of a famous mark. Whether a famous trademark is diluted is a separate question from whether an unauthorized use is likely to cause consumer confusion, which is the test for trademark infringement. (However, trademark owners often allege both dilution and confusion together when enforcing famous trademark rights.) There are different types of dilution such as blurring, tarnishment, and, in the EU, free-riding.

Trademark dilution does not necessarily involve the unauthorized use of a mark in connection with goods or services similar to those associated with the famous mark. For example, the unauthorized use of FERRARI for a brand of harmonicas may not be traditional trademark infringement, but it may be trademark dilution, even though harmonicas and luxury automobiles are unrelated. Trademark dilution laws in certain jurisdictions protect marks that are well known, highly renowned, or famous regardless of whether their unauthorized use is likely to cause consumer confusion.

To be considered well known, highly renowned, or famous, a trademark must be easily recognizable, i.e., it must be a “household name.” For example, the following would likely be considered famous marks in many countries around the world: GOOGLE, COCA-COLA, SONY, and NIKE. Each jurisdiction has its own laws and practices around the determination of what constitutes a famous or well-known mark.

2. Which jurisdictions recognize the concept of dilution?

Most jurisdictions recognize some form of trademark dilution, although the concept and associated requirements and penalties vary by jurisdiction. Jurisdictions that expressly recognize trademark dilution include the European Union, India, Japan, South Africa, the United Kingdom, and the United States. Other jurisdictions do not have specific anti-dilution laws, but some afford some form of protection from dilution to owners of well-known trademarks.

For example, in Australia, the unauthorized use of a well-known trademark in relation to goods or services that are unrelated to those associated with the well-known mark will amount to trademark infringement where the use would likely be taken as misleadingly indicating a connection with owner and thus adversely affecting the owner’s rights. Similarly, Canada prohibits unauthorized use that deprecates the goodwill of a mark.

Brazil provides an example of a jurisdiction that does not expressly use the term “dilution” in its law and continues to apply the likelihood of confusion factors as the central test for infringement, even when marks are used in different market segments. Nevertheless, Brazilian law offers strong protection to famous marks. Courts have often relied on dilution reasoning when ruling in favor of such marks, with or without formal recognition of their status by the BPTO, particularly in cases involving unrelated goods or services.

3. What are the elements of trademark dilution?

Fame—A trademark must be famous to be diluted. For example, in the United States, a mark must be widely recognized by the general consuming public to be considered famous. Fame in just one narrow industry or market (often referred to as “niche fame”) will not suffice. In the European Union, a mark must be well-known, with courts determining the level of recognition. In most jurisdictions, courts and trademark offices decide fame on a case-by-case basis.

In some jurisdictions, protection from dilution varies depending on how famous a mark is. Fame is not static, so mark owners may have to prove fame as of the date of the dilution claim or as of when the alleged diluter started using the mark. In addition, a favorable finding of fame may weaken as time passes, such that it will no longer be accepted as evidence of fame in new disputes.

Likelihood that unauthorized third-party use will blur (that is, weaken) or tarnish the distinctiveness of the famous mark—The unauthorized use must be likely to weaken the ability of the famous mark to identify and distinguish the relevant goods or services or must be likely to tarnish (harm the reputation of or diminish the prestige of) the famous mark.

In many jurisdictions, the owner of a famous mark need only show that there is a likelihood of dilution—not actual dilution.

4. What are the forms of dilution?

Blurring—Blurring is the most common type of dilution. It occurs when unauthorized use of a famous mark weakens or impairs the distinctiveness of the mark. A hypothetical example may be use of GOOGLE as a mark on toothpaste, such that consumers who previously associated the GOOGLE mark solely with the tech giant’s products begin to also associate the mark with toothpaste.

Tarnishment—Tarnishment occurs when unauthorized use of a famous mark is offensive or unflattering. This may include use of a famous mark in connection with subject matter that is critical of or offensive to the mark owner’s beliefs or reputation or that directly criticizes or attacks the mark owner or its products or services. A hypothetical example may be use of ADIDAS as a mark on a line of unhealthy food—a product in conflict with the ADIDAS brand of fitness-related products. But in some instances, tarnishment may be protected by free speech and considered “fair use” of a famous trademark, e.g., use of a mark for the purpose of parodying a famous mark’s owner or its products or services.

Free-riding—The EU recognizes a type of dilution called free-riding, which is the unauthorized use of a well-known mark on unrelated goods or services for the purpose of, or resulting in, a positive association with the well-known mark owner’s legitimate goods or services. The main purpose of recognizing this type of dilution is to prevent the unauthorized mark from benefitting unfairly from the earlier mark’s reputation. An example of free-riding may be unauthorized use of GUCCI as a mark for a high-end restaurant.

Additional Resources

Famous and Well-Known Marks
Fact Sheet

Famous and Well-Known Marks: An International Analysis
Uniquely explores the rationale for, and the history and implementation of, the protection of these exceptional trademarks.

U.S. State Trademark and Unfair Competition Law
A single source for facts, analysis, and commentary on U.S. state trademark and unfair competition law. Provides comprehensive information on trademark filing, prosecution, registration, maintenance, and enforcement on a state-by-state basis.

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