What Is Likelihood of Confusion?
The DuPont factors explained: how the USPTO and courts determine whether two marks are too similar to coexist.
The Core Test
Likelihood of confusion is the primary basis for refusing a trademark registration and for finding trademark infringement. The test asks: Is a consumer likely to be confused about the source of goods or services because two marks are too similar? This analysis goes far beyond whether two marks look or sound alike — it considers the full commercial context.
The DuPont Factors
The Trademark Trial and Appeal Board (TTAB) uses a set of 13 factors from the In re E.I. du Pont de Nemours & Co. case. While all 13 may be considered, two factors dominate most analyses: (1) the similarity of the marks in appearance, sound, meaning, and commercial impression; and (2) the relatedness of the goods or services.
Similarity of the Marks
The USPTO compares marks in their entirety — including appearance, sound, meaning, and overall commercial impression. Marks don't need to be identical to be confusingly similar. GOGLE and GOOGLE, or COCA-COLA and KOKA-KOLA, would likely be found confusingly similar despite differences in spelling. Courts also consider whether the marks share a dominant element, even if other elements differ.
Relatedness of Goods and Services
Even identical marks can coexist if the goods or services are unrelated. DELTA for airlines and DELTA for faucets are separate because consumers don't expect a single company to make both. However, the goods don't need to be identical — they just need to be related enough that consumers might assume a common source. Software and computer hardware, for instance, are closely related.
Channels of Trade and Classes of Consumers
Where and how goods are sold matters. If two products are sold through the same retail channels (e.g., both online and in department stores) to the same consumers, confusion is more likely. Conversely, products sold in completely different markets to different customers are less likely to cause confusion.
Fame of the Prior Mark
Famous marks receive broader protection. A mark like NIKE or COCA-COLA is so well-known that even a somewhat different mark in a tangentially related field could cause confusion. The more famous the prior mark, the wider the zone of protection.
How This Affects Your Filing
Before filing a trademark application, it's essential to search for potentially conflicting marks and evaluate the likelihood of confusion. A well-conducted clearance search can identify potential conflicts early, saving you from an expensive refusal or opposition down the road.
Disclaimer: This article provides general information about trademark law and is not legal advice. Every situation is unique, and the information here may not apply to your specific circumstances. Consult a licensed attorney for advice tailored to your situation.
Run a free trademark search to identify potentially conflicting marks before filing your application.
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