upgrade

💡intro to intellectual property review

Likelihood of Confusion

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Likelihood of confusion is a key concept in trademark law that determines whether the use of a trademark by one party is likely to cause consumer confusion with the trademark of another party. It is a central consideration in evaluating trademark infringement claims.

5 Must Know Facts For Your Next Test

  1. Likelihood of confusion is the primary test used to determine whether trademark infringement has occurred.
  2. Courts consider a variety of factors, such as the similarity of the marks, the strength of the plaintiff's mark, and the proximity of the goods or services, to assess the likelihood of consumer confusion.
  3. The likelihood of confusion analysis applies to both the registered trademark and any confusingly similar unregistered common law trademarks.
  4. Likelihood of confusion can exist even if the goods or services are not directly competitive, as long as there is a likelihood that consumers will be confused about the source or sponsorship of the products.
  5. The burden of proving likelihood of confusion is on the trademark owner alleging infringement.

Review Questions

  • Explain how the likelihood of confusion test is used to evaluate trademark infringement claims.
    • The likelihood of confusion test is the primary legal standard used to determine whether trademark infringement has occurred. Courts consider a variety of factors, such as the similarity of the marks, the strength of the plaintiff's mark, the proximity of the goods or services, the marketing channels used, the degree of care exercised by consumers, and the intent of the defendant. If the court finds that the defendant's use of a trademark is likely to cause consumer confusion with the plaintiff's trademark, then the defendant's use is considered infringing, even if the goods or services are not directly competitive.
  • Describe how the concept of trademark distinctiveness relates to the likelihood of confusion analysis.
    • The distinctiveness of a trademark is a key factor in the likelihood of confusion analysis. Trademarks that are more distinctive, either inherently or through acquired distinctiveness, are more likely to be protected from confusingly similar uses. Highly distinctive marks, such as arbitrary or fanciful marks, are afforded a broader scope of protection because consumers are more likely to associate them with a single source. In contrast, less distinctive marks, such as descriptive or generic marks, receive narrower protection because consumers may be more accustomed to seeing similar marks used by different parties, reducing the likelihood of confusion.
  • Evaluate how the likelihood of confusion test applies to both registered and unregistered trademarks, and explain the significance of this application.
    • The likelihood of confusion test applies not only to registered trademarks, but also to unregistered common law trademarks. This means that a trademark owner can assert infringement claims against a party using a confusingly similar mark, even if the owner's mark is not federally registered. The application of the likelihood of confusion test to both registered and unregistered trademarks is significant because it provides broader protection for trademark owners and recognizes the common law rights that can be established through use of a mark in commerce. This ensures that consumers are protected from being misled about the source of goods or services, regardless of whether the trademark is registered with the government.