When the USPTO examines trademark applications or when courts assess potential trademark infringement, they rely on a multifaceted analysis to determine whether two marks are likely to cause consumer confusion. The framework established in In re E.I. DuPont DeNemours & Co.,1 sets forth thirteen factors to guide this inquiry. Among these, the sixth DuPont factor—examining the number and nature of similar marks in use on similar goods—plays a unique and often decisive role.
Understanding the Sixth DuPont Factor
The sixth DuPont factor asks: “the number and nature of similar marks in use on similar goods.” This factor serves a dual purpose. First, when a particular term, prefix, suffix, or design element is commonly used in a given industry, consumers become accustomed to distinguishing between different marks that share these common elements.
Third-party registrations that cover the goods or services of the applicant and registrant may have some probative value to the extent that they may serve to suggest that goods or services are of a type that may emanate from a single source, if the registrations are based on use in commerce.2
Second, third-party use and registrations serve as evidence that a term or design has become crowded in a particular field. When numerous companies use similar marks for related goods or services, that a mark or a portion of a mark has a normally understood descriptive or suggestive connotation, leading to the conclusion that the term or mark component is relatively weak.3
The logic underlying the sixth DuPont factor is straightforward: if many marks coexist peacefully in the marketplace sharing similar elements, it demonstrates that consumers can distinguish between the similarities. Further, the scope of protection should be narrow because it would be anti-free market to allow a trademark owner to monopolize an element that the entire industry needs to describe or identify their goods or services.
Third-party registrations, even if not evidence of actual marketplace use, remain probative. They demonstrate that the USPTO has repeatedly allowed similar marks to coexist, suggesting the examining attorneys determined that confusion was unlikely. While third-party registrations alone carry less weight than evidence of actual third-party use, they still inform the analysis of commercial strength and the crowded nature of the trademark landscape.
The Trademark Trial and Appeal Board (TTAB) as well as the federal courts consider both the quantity and quality of third-party evidence. A handful of registrations may carry little weight, but dozens of similar marks – particularly when accompanied by evidence of actual marketplace use – can be dispositive.
However, the evidence must be relevant. Third-party marks should be similar in appearance, sound, or meaning to the marks at issue and used in connection with related goods or services. Generic similarities or marks from unrelated fields have low probative value.
The sixth factor was featured in the holding of a recent Federal Circuit decision. In Apex Bank v. CC Serve Corp.,4 the Federal Circuit panel vacated the TTAB’s analysis of third-party registrations and the similarity of the marks (ASPIRE and ASPIRE BANK, both in Class 36, for various financial, banking, and credit card services).
The court identified a critical inconsistency in the TTAB’s approach. Under the second DuPont factor, the TTAB determined that credit card services and banking and financing services were “legally identical, in part” and highly similar. However, in its analysis, the TTAB restricted its consideration to only marks relating to credit card services and excluded marks related to other banking and financing services. In doing so, the TTAB considered only nine third-party registrations to be relevant. The Federal Circuit firmly rejected this divergent approach. The TTAB should have considered the other 42 third-party registrations with ASPIRE or an ASPIRE-formative mark in other banking and financial services.
Takeaways
This decision reinforces several important points for trademark practitioners:
- Consistency is mandatory: decision-makers must apply consistent definitions of “similar” services throughout the DuPont factor analysis. A finding of high similarity in one factor should inform the scope of analysis in other factors.
- Scope matters: third-party evidence is most persuasive when it demonstrates crowding in the relevant marketplace. If goods or services are deemed highly similar for purposes of the second factor, the universe of relevant third-party marks expands accordingly under the sixth factor.
- Interconnected factors: the court also vacated the TTAB’s analysis of the first DuPont factor (similarity of the marks) because reconsideration of the sixth DuPont factor may result in a different determination of the mark’s commercial strength or weakness and affect the overall commercial impression. This demonstrates how the factors interrelate—a finding of weakness under the sixth factor can influence the analysis of similarity under the first factor.
Conclusion
The sixth DuPont factor in a likelihood of confusion analysis means that the scope of relevant third-party use and registrations must align with similarity determinations made elsewhere in the analysis. This decision should encourage more robust third-party evidence submissions and careful attention to how similarity is defined consistently throughout likelihood of confusion proceedings.
This posting is purely informational only and should not be deemed legal advice. For more information on this issue or trademark law, please contact Yonaxis I.P. Law Group.
- 476 F.2d 1357 (CCPA 1973). Note that the DuPont test is the standard used for a likelihood of confusion analysis in the Federal Circuit’s jurisdiction; this is not the same likelihood of confusion test for all circuit courts of appeals. ↩︎
- See TMEP 1207.01(d)(iii); Hewlett-Packard Co. v. Packard Press, Inc., 281 F.3d 1261, 1267, 62 USPQ2d 1001, 1004 (Fed. Cir. 2002). ↩︎
- See TMEP 1207.01(d)(iii); Spireon, Inc. v. Flex Ltd., 71 F.4th 1355, 1363, 2023 USPQ2d 737, at *4-5 (Fed. Cir. 2023); Jack Wolfskin Ausrustung Fur Draussen GmbH & Co. KGAA v. New Millennium Sports, S.L.U., 797 F.3d 1363, 116 USPQ2d 1129 (Fed. Cir. 2015); Juice Generation, Inc. v. GS Enters. LLC, 794 F.3d 1334, 1339, 115 USPQ2d 1671, 1675 (Fed. Cir. 2015). ↩︎
- ___F.4th___, Case No. 2023-2143 (Fed. Cir. September 25, 2025). ↩︎