13 Du Pont Factors: USPTO Trademark Likelihood of Confusion

Entrepreneurs and business owners often approach federal trademark registration with equal parts excitement and anxiety. You’ve chosen a name you like, you’ve started using it, and you’re ready to lock it in with a federal registration—only to receive a trademark refusal from the USPTO citing a “likelihood of confusion” under Section 2(d) of the Lanham Act. In plain terms, the USPTO is saying: “Your mark is too close to someone else’s mark for related goods or services, and consumers might think they come from the same source.”

Likelihood of confusion is the central test in both trademark registration disputes and many trademark infringement disputes. Courts and the USPTO treat it as the key question for protecting consumers from confusion about source, sponsorship, affiliation, or connection—not just identical brand names on identical products.

To analyze that question, the USPTO and the Trademark Trial and Appeal Board (TTAB) typically apply a set of considerations drawn from a landmark 1973 decision: In re E. I. du Pont de Nemours & Co. In that decision, the court emphasized there is no single “litmus test.” Instead, decision-makers weigh a collection of factors—thirteen in all—when they’re relevant to the facts. Importantly, not every factor matters in every case, and sometimes one factor can carry the day.

Below is a practical, business-owner-friendly walkthrough of the Du Pont factors, along with strategy tips that can help reduce risk before responding effectively if you’re facing a Section 2(d) refusal. Note, if you or your business is facing a Section 2(d) likelihood of confusion office action, our trademark attorneys can assist. Please contact our law office to schedule a free consultation.

How the Du Pont Analysis Works

Think of the Du Pont factors as a checklist of “confusion drivers.” Some relate to the trademarks themselves. Others relate to the goods or services, how they’re sold, and what consumers experience in the marketplace. The TTAB has repeatedly observed that, in many cases, the two most important considerations are the similarity of the trademarks and the similarity (or relatedness) of the goods or services.

Also remember the procedural lens matters. In a typical trademark application examination, the USPTO is deciding the “right to register,” not the “right to use.” That means the analysis focuses heavily on the wording in the application and cited registration, and it relies on legal presumptions about trade channels and purchasers when the identifications are broad or unrestricted.

Similarity of the Trademarks in Their Entireties

This factor asks whether the trademarks are similar in appearance, sound, meaning (connotation), and overall commercial impression. You don’t “win” this factor simply by changing a font, adding a design flourish, or tweaking one letter if the overall impression remains close. Decision-makers look at the trademarks as a whole and consider how an ordinary consumer—often with an imperfect or “hazy” memory—would perceive them in the marketplace.

A common entrepreneur mistake is focusing on side-by-side comparisons. Real consumers typically don’t see brands in a courtroom-style lineup. They encounter a trademark in context, remember it imperfectly, and later see another trademark that might trigger the same impression. If the dominant portion of your trademark closely echoes a prior trademark, the USPTO may find this factor favors refusal even if other differences exist.

Similarity and Nature of the Goods or Services as Described

Here, the USPTO compares the goods/services as written in the trademark application and the cited trademark registration—not how you personally plan to sell them. If your identification is broad, the USPTO must assume it includes all items within that broad wording. For example, “furniture” can legally encompass narrower furniture categories. And goods in different USPTO classes can still be considered related; trademark classification does not control the likelihood-of-confusion analysis.

Practical tip: overbroad identifications can create avoidable problems. Narrow, accurate descriptions can sometimes reduce the overlap the USPTO must presume, and in some cases, carefully drafted limitations can move this factor in your favor.

Similarity of Established, Likely-To-Continue Trade Channels

This factor asks where the goods/services travel and how consumers encounter them. In ex parte examination, if both the application and registration are unrestricted, the USPTO generally presumes the goods/services move through the same channels of trade to the same classes of purchasers.

That presumption is why “We only sell online” or “We only sell in boutiques” often fails unless the limitation actually appears in the identification (and even then, the limitation must be meaningful and acceptable under USPTO rules). Thoughtful channel limitations can matter, but they must be real, supportable, and drafted correctly.

Conditions of Sale and Buyer Sophistication

This factor looks at whether purchases are impulsive or careful and whether purchasers are sophisticated. A buyer choosing a low-cost snack at a checkout line behaves differently than a purchasing manager selecting expensive industrial equipment after weeks of comparison. When purchases are expensive, specialized, or made by trained professionals, confusion can be less likely.

That said, sophistication is not a magic shield. Even sophisticated buyers can be confused by similar trademarks in adjacent categories, especially when brand extensions are common. The question is always: under these buying conditions, would confusion be likely?

Fame of the Prior Trademark

A famous mark often gets a broader scope of protection. The logic is intuitive: if consumers strongly associate a trademark with a single source, they may assume the brand is expanding into related areas. In routine USPTO examination, however, examining attorneys typically are not expected to prove fame; when there is no fame evidence, the “fame” factor is often treated as neutral in ex parte proceedings.

For entrepreneurs, the business takeaway is simple: if the cited trademark is widely recognized (even if the record doesn’t formally prove it), you should assume the risk profile is higher and plan your branding strategy accordingly.

Number and Nature of Similar Trademarks in Use on Similar Goods

This is where “crowded field” or “weak trademark” arguments come into play. If many third parties use similar wording for similar goods/services, consumers may learn to distinguish those trademarks based on small differences, and any one owner’s scope of protection may be narrower. But the persuasive version of this argument usually depends on marketplace evidence—proof that consumers actually encounter those third-party marks—not just a stack of registrations.

For business owners, this factor can be a double-edged sword. A crowded space may make refusal easier to fight, but it can also mean your chosen brand is inherently harder to protect long-term.

Nature and Extent of Any Actual Confusion

Evidence of real-world confusion can be powerful, especially in litigation. In USPTO examination, it’s less common to see robust evidence either way. Still, documented confusion (misdirected emails, customer calls, mistaken online reviews, reseller mix-ups) can strongly support a refusal or an opposition.

If you’re already operating, it’s smart to keep a record of confusion-related incidents—whether they support your position or signal you should pivot. Either way, those facts can matter later.

Length of Time and Conditions of Concurrent Use Without Confusion

Applicants often argue, “We’ve been using this for years and no one has complained.” The USPTO generally gives little weight to unsupported assertions like that, because confusion can go unreported and because the question is likelihood, not proof of past mistakes. Where this factor has traction, it usually involves meaningful, contemporaneous use in overlapping markets under similar conditions—backed by evidence.

In short: “no known confusion” can help, but only when it’s real, documented, and tied to substantial market exposure.

Variety of Goods on Which the Prior Trademark is Used

This factor considers whether a trademark is used as a “house mark” across a wide range of products/services or as a narrower product-specific brand. A broad “family” or house-mark use can increase the chance that consumers would assume the same company is behind a new, related offering—especially when the trademarks are close and brand extensions are common.

For entrepreneurs, this is a reminder to research the real footprint of the cited trademark. If the registrant uses the trademark broadly, your risk increases. If the trademark is used narrowly and in a specialized niche, you may have more room—though the registration wording still matters.

Market Interface Between the Parties (including Consent Agreements)

This factor can be one of the most strategic tools available. It covers how the parties interact in the marketplace, including agreements such as consents to register, coexistence terms designed to avoid confusion, and other practical arrangements.

A properly drafted consent agreement can carry substantial weight. The USPTO is not automatically bound by a consent, but courts have emphasized that the parties closest to the marketplace are often best positioned to assess confusion risk. Consents that include specific measures to prevent confusion—sometimes called “clothed” consents—tend to carry more persuasive weight than bare-bones “naked” consents.

From a business perspective, a consent agreement is not just a signature on a page. The strongest consent agreements explain why confusion is unlikely and outline concrete guardrails (branding presentation rules, channel limitations, cooperation if confusion arises, and similar practical steps).

The Trademark Applicant’s Right to Exclude Others From Use of its Trademark

This factor asks whether the applicant has strong proprietary rights that would support excluding others. In practice, it’s often more relevant in inter partes disputes than in a typical ex parte refusal, but it can matter when an applicant can show significant prior rights, a strong brand position, or other proof of exclusivity.

For entrepreneurs, the larger lesson is to build your brand strength early: consistent use, consistent presentation, and careful policing of copycats can improve your position over time.

Extent of Potential Confusion: De Minimis or Substantial

Not every theoretical confusion risk is treated the same. This factor asks whether confusion would be minor and rare or meaningful and widespread. In some industries—especially fast-moving consumer goods—small amounts of confusion can still be commercially significant. In others, the question becomes whether confusion would meaningfully impact decisions, reputation, or purchasing behavior.

Any Other Established Fact Probative of the Effect of Use

This is the “catch-all” factor, and it matters because trademark disputes are about real consumer perception. The Du Pont framework is intentionally flexible so that decision-makers can account for other credible facts that shed light on whether consumers would be confused.

In practice, this is where modern evidence can play a role: online marketplace conditions, search results that show consumer behavior, the way consumers abbreviate brands, how products are displayed on e-commerce platforms, and other facts that weren’t front-and-center decades ago but are central today.

Two Procedural Rules Entrepreneurs Often Learn the Hard Way

First, if you’re facing a Section 2(d) likelihood of confusion refusal, you generally cannot attack the validity of the cited registration during ex parte prosecution. Arguments like “their trademark is descriptive,” “they’re not using it,” or “they abandoned it” are typically treated as improper collateral attacks and must be raised through other procedures (like a cancellation action), not in the middle of your trademark application response.

Second, when the case is close, the USPTO often resolves doubt in favor of the senior user (the owner of the cited registration). That policy puts a premium on proactive clearance and thoughtful filing strategy before you invest heavily in a name.

A Quick Note on “Fact vs. Law”: Why Results Can Feel Unpredictable

Likelihood of confusion is famously fact-intensive. Most federal circuits generally treat it as a factual determination on appeal, while a minority have treated the ultimate conclusion as more of a legal determination (with factual findings underneath). Either way, the practical takeaway is the same: small record differences can change outcomes, and well-developed evidence matters.

Conclusion: Using Du Pont as a Business Roadmap, Not Just a Legal Test

The Du Pont factors aren’t just a checklist for lawyers—they’re a practical map for building a brand that can clear registration and remain defensible in the real world. If you want to reduce your risk of a Section 2(d) refusal, focus early on the two pressure points that drive most decisions: choose a trademark with a distinct overall commercial impression, and make sure your goods/services (as written in your application) don’t create unnecessary overlap with existing registrations.

When risk appears, don’t default to cosmetic tweaks. Consider smarter moves: refining your identification of goods/services, gathering meaningful marketplace evidence of third-party use in a crowded field, and—when appropriate—exploring a well-crafted consent agreement that includes real-world guardrails.

Most importantly, treat trademark searches and filing strategy as part of your business planning, not an afterthought. A little diligence up front can save months of delay, significant legal fees, and the far more painful cost of a forced rebrand after you’ve built momentum.