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  • Writer's pictureTamara Pester

13 factors to analyze trademark confusion

Updated: Nov 22, 2023

Why the U.S. Patent and Trademark Office looks for trademark confusion

One of the most common reasons Examining Attorneys at the U.S. Patent and Trademark Office (“PTO”) initially refuse registration of trademarks is “likelihood of confusion.” The PTO checks to make sure that trademark subject of a new application will not be confused with another registration or pending application that already exists in their database. Under Section 2(d) of the Trademark Act, “a mark which so resembles a mark registered in the Patent and Trademark Office, or a mark or trade name previously used in the United States by another and not abandoned, as to be likely, when used on or in connection with the goods of the applicant, to cause confusion, or to cause mistake, or to deceive” may NOT achieve registration with the PTO.


A case known as In re E. I. du Pont de Nemours & Co., 476 F.2d 1357 (C.C.P.A. 1973) famously set out thirteen factors to be considered in a likelihood of confusion analysis. The DuPont case's thirteen factors are essential to determining whether a new trademark can exist alongside an already established one, or if it will be considered "confusingly similar" by the U.S. Patent and Trademark Office (or a prior owner). These factors provide guidelines used by the USPTO and courts to evaluate the likelihood of confusion between two trademarks. In this analysis, we will explore the 13 DuPont factors and emphasize the key factors that carry significant importance in this assessment procedure.


The 13 DuPont Factors used to assess trademark confusion

When analyzing whether two trademarks are too close to each other to allow the newer one to be used and registered, a trademark attorney conducts an analysis of the thirteen DuPont factors:


(1) The similarity or dissimilarity of the marks in their entireties, considering appearance, sound, connotation and commercial impression.


(2) Whether the goods or services described in an application or registration or used in connection with a prior mark are similar or dissimilar.


(3) Whether the trademark owners use similarity or dissimilar established, likely-to-continue trade channels to sell their goods or services.


(4) The conditions under which and buyers to whom sales are made (i. e. “impulse” vs. careful, sophisticated purchasing).


(5) The fame of the prior mark (sales, advertising, length of use).


(6) The number and nature of similar marks in use on similar goods.


(7) The nature and extent of any actual confusion (i.e. - are customers calling one party, thinking it's the other? Are people leaving negative Google reviews for a company who offers goods or services of a lesser quality than the original owner of the trademark?)


(8) The length of time during and conditions under which there has been concurrent use without evidence of actual confusion -- the longer period of coexistence without any issues, the stronger argument the newer user has to be able to continue.


(9) The variety of goods on which a mark is or is not used (house mark, “family” mark, product mark).


(10) The market interface between applicant and the owner of a prior mark:

(a) a mere “consent” to register or use.

(b) agreement provisions designed to preclude confusion, i. e. limitations on continued use of the marks by each party.

(c) assignment of mark, application, registration and good will of the related business.

(d) laches and estoppel attributable to owner of prior mark and indicative of lack of confusion.


(11) The extent to which an applicant has a right to exclude others from use of its mark on its goods.


(12) The extent of potential confusion, i. e., whether de minimis or substantial.


(13) Any other established fact probative of the effect of use.


The most important factors are almost always the similarity or dissimilarity of the marks in their entireties - whether they look and sound alike, and give the same commercial impression, as well as the similarity or dissimilarity and nature of the goods or services offered by each party. The likelihood of confusion is best analyzed on a mark-by-mark basis, and an experienced trademark attorney can craft arguments based on case law and analysis to overcome Examining Attorneys’ initial rejections.

Photo by Emily Morter on Unsplash


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