The DuPont factors are the 13 criteria the USPTO uses to decide likelihood of confusion in trademark cases under Section 2(d) of the Lanham Act.
Originally Published: | Last Updated:
By Michael Kondoudis, USPTO-Registered Attorney With 25+ Years of Trademark Experience
Inventor of the YNAT® Trademarking System | 3,000+ Trademarks & Patents Secured | Amazon #1 Best-Selling Author on Trademarks | Member of the Bar of the U.S. Supreme Court | Trademarks Made Easy®
Key Takeaways
The DuPont factors are a legal framework used in US trademark law to determine if two trademarks are confusingly similar.
- Definition: A 13-point qualitative balancing test used by the USPTO to determine a trademark's "likelihood of confusion" under Section 2(d) of the Lanham Act.
- Legal Origin: Established by the 1973 landmark judicial decision In re E.I. du Pont de Nemours & Co.
- Primary Drivers: There are exactly 13 DuPont factors, but Factor 1 (mark similarity), Factor 2 (goods/services relatedness), and Factor 3 (trade channels) are the most important.
- Most Frequent USPTO Rejection: The most common refusal at the USPTO are Section 2(d) likelihood of confusion rejections based on application of the DuPont factors.
- Can Be Used to Overcome USPTO Refusals: Many likelihood of confusion refusals can be overcome with the right evidence and strategy.
What Are The DuPont Factors USPTO Examiners Use For Likelihood of Confusion?
Legal Origin Of The DuPont Factors: Definition and Legal Origin
- The Initial Trademark Conflict: The dispute arose when E.I. du Pont de Nemours & Co. sought to register the trademark “RALLY” for a specialized car wax. The USPTO examiner rejected the application, citing a pre-existing registration for an identical “RALLY” trademark owned by Horizon Industries for an all-purpose household detergent.
- The Coexistence Agreement: To resolve the overlap, DuPont and Horizon executed a formal trademark coexistence agreement. The contract explicitly limited Horizon to the household market and confined DuPont to the automotive market, ensuring their distribution paths and marketing campaigns would never cross.
- The USPTO’s Initial Stagnant Stance: The USPTO and the Trademark Trial and Appeal Board (TTAB) ignored the agreement and maintained the refusal. The agency argued that because the literal text of the marks was identical, consumer confusion remained inevitable regardless of any private contractual boundaries.
- The Landmark CCPA Appellate Ruling: On appeal, the CCPA reversed the TTAB decision, ruling that sophisticated business agreements provide powerful evidence that confusion is unlikely. The court declared that the USPTO cannot analyze trademarks in a vacuum and outlined 13 specific criteria to guide all future likelihood of confusion evaluations.
Differences Between DuPont Factors vs. Polaroid and Sleekcraft Factors: Regional Circuit Variations
The differences among DuPont, Polaroid, and Sleekcraft factors are their legal jurisdiction and application within US trademark law. While the USPTO and the Federal Circuit strictly apply the 13 DuPont criteria during trademark application review, regional federal courts use localized multi-factor variants—such as the Second Circuit’s Polaroid factors or the Ninth Circuit’s Sleekcraft factors—to resolve questions of potential confusion in active trademark infringement lawsuits.
Regional US federal courts apply their own local variations of the DuPont factors, most notably the Polaroid Factors in the Second Circuit and the Sleekcraft Factors in the Ninth Circuit. While the USPTO and the Federal Circuit strictly use the 13 DuPont criteria, individual regional courts use these localized multi-factor tests to answer questions about the likelihood of confusion.
This structured reference table maps out exactly how each US judicial circuit labels and cites its respective likelihood of confusion evaluation framework:
Trademark Framework Comparison Matrix
by U.S. Court of Appeals and the USPTO
| Jurisdiction / US Court of Appeal | Framework | Landmark Legal Case |
|---|---|---|
| USPTO / Federal Circuit / 1st, 3rd-8th, 10th, 11th, DC Circuits | DuPont factors | In re E.I. du Pont de Nemours & Co.,476 F.2d 1357 (1973) |
| Second Circuit (NY, CT, VT) | Polaroid Factors | Polaroid Corp. v. Polarad Elecs. Corp., 287 F.2d 492 (1961) |
| Ninth Circuit (AK, AZ, CA, HI, ID, MN, NV, OR, WA) | Sleekcraft Factors | AMF Inc. v. Sleekcraft Boats, 599 F.2d 341 (1979) |
Why Are the DuPont Factors Important for Federal Trademark Registration?
- Determines Federal Registration Eligibility: The USPTO relies exclusively on the DuPont factors to review incoming trademark applications. If an applicant’s mark shares conflicting similarities with an existing registration across high-weight factors, the agency issues a Section 2(d) refusal, halting the path to federal protection.
- Mitigates High-Stakes Financial Risk: Launching a brand without evaluating the DuPont matrix exposes a company to catastrophic financial liabilities. If an established competitor proves a likelihood of confusion under these standards, courts can issue injunctions that force immediate product recalls, website deactivations, and the destruction of physical inventory.
- Establishes Clear Legal Boundaries for Brand Expansion: The DuPont framework serves as a predictive roadmap for corporate scaling. By assessing Factor 2 (relatedness of goods) and Factor 3 (trade channels), a business can verify if its target expansion categories are safely clear or if nearby brands will block entry into new retail verticals.
- Provides a Structured Blueprint for Infringement Defense: When defending a brand against a cease-and-desist letter or an active federal lawsuit, the DuPont factors provide the exact criteria needed to defeat an infringement claim. Winning a defense requires systematically proving that consumer confusion is mathematically and commercially improbable based on the multi-factor test.
Bottom line: The DuPont factors are not just academic. They directly affect whether you can secure nationwide trademark rights — and how much time, money, and effort it will take to get there.
What Are the 13 DuPont Factors? Legal Criteria and Weight Matrix
| # | Factor Name | Typical Weight | Key Insight for Applicants |
|---|---|---|---|
| 1 | Similarity of the Marks | High-often pivotal | Appearance, sound, meaning, and overall commercial impression |
| 2 | Similarity or Relatedness of the Goods or Services | High- often pivotal | How connected the products or services are in consumers’ minds |
| 3 | Similarity of Established Trade Channels | High | Whether the brands reach customers through the same stores, websites, or platforms |
| 4 | Conditions of Sale and Buyer Sophistication | Medium-context dependent | Impulse purchases vs. careful, researched buying decisions |
| 5 | Fame of the Prior Mark | Medium | Famous marks receive significantly broader protection |
| 6 | Number and Nature of Similar Marks in Use | Medium-context dependent | A “crowded field” can make a mark weaker and easier to distinguish |
| 7 | Nature and Extent of Actual Confusion | Medium | Real-world evidence of consumer mix-ups (helpful but not required) |
| 8 | Length of Time of Concurrent Use Without Confusion | Low–Medium - fact specific | Long peaceful coexistence strongly supports registration |
| 9 | Variety of Goods on Which a Mark Is Used | Low | House marks used across many categories receive broader protection |
| 10 | Market Interface Between the Parties | High (if present) | Consent or coexistence agreements are very persuasive |
| 11 | Extent to Which Applicant Has a Right to Exclude Others | Low | Descriptive or weak marks have narrower exclusionary rights |
| 12 | Extent of Potential Confusion | Medium | How substantial the real-world overlap between the parties actually is |
| 13 | Any Other Probative Fact | Variable | Catch-all factor for unique marketplace realities not covered elsewhere |
How Does the USPTO Evaluate Likelihood of Confusion Using DuPont Factors?
The USPTO evaluates trademark likelihood of confusion by reviewing all 13 DuPont criteria on a qualitative sliding scale based on real-world marketplace realities. Examining attorneys do not look at application files in a vacuum; instead, they weigh core pillars together to determine if an applied-for mark creates a conflicting overall commercial impression with a pre-existing registration.
This is exactly how the USPTO actually applies the DuPont factors:
Factor 1: Similarity of the Marks
This factor weighs the similarities of the marks in how they look, how they sound, and what they mean in the minds of consumers.
Why it matters: Even small differences in spelling, pronunciation, or overall “feel” can be enough to create confusion when goods or services are related.
Example: Registering “Klear” for cleaning products when “Clear” is already registered in the same field is legally refused.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 1, applicants must emphasize differences in commercial impression and overall look-and-feel rather than nitpicking minor spelling variations. Provide clear side-by-side comparisons in your response. Do not waste arguments on minor spelling or visual differences.
Factor 2: Relatedness of the Goods or Services
This factor determines whether the relevant products or services are commercially connected, complementary, or associated within the minds of ordinary consumers.
Why it matters: When goods or services are unrelated, consumers are unlikely to assume they come from the same source, even if the marks share some similarity.
Example: The mark “Delta” is used successfully by both a major airline and a plumbing fixtures company because airplanes and bathroom faucets are entirely unrelated goods.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 2, applicants must clearly distinguish your goods or services from those listed in the cited registration. Use precise descriptions and, when helpful, marketplace evidence showing how the industries differ.
Factor 3: Similarity of Established Trade Channels
This factor examines where and how the businesses market, distribute, and sell their products or services.
Why it matters: When two brands target the same customers through the same stores, websites, or distribution methods, the risk of confusion rises significantly.
Example: Two independent clothing creators using similar brand names to sell custom t-shirts on Etsy face higher risk because their trade channels are identical.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 3, applicants must highlight meaningful differences in sales channels, target customers, price points, or distribution methods when they exist.
Factor 4: Conditions of Sale and Buyer Sophistication
This factor measures the degree of care and deliberation a consumer exercises before making a purchase.
Why it matters: Sophisticated buyers who research carefully are less likely to be confused by similar marks than impulse purchasers.
Example: Corporate procurement managers buying a $50,000 enterprise software suite research vendors thoroughly, while an impulse shopper grabbing a $5 candy bar makes a quick decision with little research.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 4, applicants must emphasize high price points, long sales cycles, expert purchasers, or complex decision-making processes when they apply to your goods or services.
Factor 5: Fame of the Prior Mark
This factor considers the level of recognition and fame of the earlier mark.
Why it matters: Extremely famous marks receive significantly broader protection and can block registration even in unrelated fields.
Example: A local computer repair shop named “Nike Tech Fix” would likely be refused because the extreme fame of the Nike athletic brand overrides the difference in industries.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 5, applicants must focus on strong distinctions in the other key factors (especially 1 and 2) and consider whether a consent agreement may be necessary. Famous marks are difficult to overcome.
Factor 6: Number and Nature of Similar Marks in Use
This factor explores whether the mark (or similar terms) is already widely used by third parties in the same or related fields.
Why it matters: When many businesses already use similar terms, the prior mark is considered weaker, and consumers are better at distinguishing between them.
Example: If dozens of fitness businesses already use the word “Summit,” the USPTO is more likely to allow “Summit Elite Training” because consumers already differentiate between various “Summit” gyms.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 6, applicants must submit evidence of third-party registrations and real-world marketplace uses (the “crowded field” argument). This is often one of the most effective ways to overcome a refusal.
Factor 7: Nature and Extent of Actual Confusion
This factor considers evidence showing that real consumers have actually mistaken one business for another.
Why it matters: Documented instances of confusion provide strong proof, although the absence of actual confusion does not automatically disprove likelihood of confusion.
Example: Customer service logs showing buyers repeatedly calling a rival restaurant to place orders serves as compelling evidence of actual confusion.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 7, applicants need to focus primarily on the stronger factors (1–3) unless they have clear documentation of actual confusion.
Factor 8: Length of Time of Concurrent Use Without Confusion
This factor examines whether the marks have coexisted in the marketplace for a significant period without documented consumer confusion.
Why it matters: Long, peaceful coexistence strongly suggests that future confusion is unlikely.
Example: Two regional bakeries using variants of “Sweet Treats” operating in neighboring towns for 10 years with no mixed-up deliveries or customer complaints provide excellent supporting evidence.
Applicant Strategy: If applicable, document the length of concurrent use and the absence of any confusion incidents. This factor carries more weight when the period of coexistence is substantial.
Factor 9: Variety of Goods on Which a Mark Is Used
This factor looks at whether the prior mark is used on a narrow range of goods or as a broad “house brand” that expands across many categories.
Why it matters: Well-known house brands (such as GE or Sony) that routinely expand into new product lines receive broader protection than single-product brands.
Example: A mark used only on one narrow product line generally has more limited protection than a famous house mark used across electronics, appliances, and financial services.
Applicant Strategy: This factor is not relevant unless the cited mark is a broad, well-known house brand.
Factor 10: Market Interface Between Parties / Consent Agreements
This factor considers formal agreements between the parties, particularly consent or coexistence agreements.
Why it matters: A properly drafted consent agreement in which the owner of the prior mark gives written permission for registration can carry significant weight.
Example: An existing trademark owner signs a coexistence agreement that limits the new applicant’s goods, services, or trade channels in exchange for consent to register.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 10, applicants must present a structured coexistence agreement with meaningful limitations on use. A bare statement of consent has limited value. A rigorous and structured coexistence agreement is far more persuasive to examining attorneys.
Factor 11: Extent to Which Applicant Has a Right to Exclude Others
This factor considers the scope of the applicant’s existing trademark rights and ability to prevent others from using similar branding.
Why it matters: Highly descriptive or weak marks have narrower exclusionary rights, which can affect how the USPTO views the overall strength of the applicant’s position.
Example: A merely descriptive mark generally has limited ability to exclude others compared with a strong, arbitrary, or fanciful mark.
Applicant Strategy: This factor is only relevant when you already own prior registrations that strengthen your position.
Factor 12: Extent of Potential Confusion
This factor evaluates whether the risk of consumers being misled is substantial or merely minimal and incidental.
Why it matters: When the actual marketplace overlap between the parties is very limited, the potential for meaningful confusion decreases.
Example: One brand sells exclusively through secure government bids while the other sells only on social media and direct-to-consumer websites — the scope of potential overlap is minimal.
Applicant Strategy: To overcome a Section 2(d) refusal using DuPont Factor 1, applicants must clearly demonstrate limited real-world overlap in customers, channels, or geographic reach when it exists.
Factor 13: Any Other Probative Fact
This is the catch-all factor that allows examining attorneys to consider any other relevant evidence or marketplace realities not covered by the first 12 factors.
Why it matters: Unique trends, consumer behaviors, or industry-specific conditions can influence how consumers perceive the source of goods or services.
Example: Rapid changes in an industry (such as new technology platforms or shifting consumer habits) may affect whether confusion is likely.
Applicant Strategy: This factor is a catch-all. Use it to introduce any distinctive marketplace facts that support your position and are not addressed elsewhere.
Which DuPont Factors Are Most Important in a Likelihood of Confusion Analysis?
1. DuPont Factor 1: Similarity of the Marks
- Appearance: Visual similarities in spelling, layout, punctuation, font choice, and design elements.
- Phonetic Sound: Auditory identity or equivalence when spoken aloud during normal commercial use.
- Connotation: Shared definitions, underlying meanings, or matching ideological associations.
- Contextual Feel: The overarching psychological impression or commercial vibe projected to consumers.
2. DuPont Factor 2: Relatedness of the Goods or Services
- Complementary Use: Products commonly used together, such as smartphones and protective cases.
- Shared Production Source: Distinct items routinely manufactured by the same company, like apparel and footwear.
- Industry Association: Products entering the market under a unified sector umbrella, such as software applications and IT consulting services.
3. DuPont Factor 3: Similarity of Established Trade Channels
- Retail Environments: Shared presence in identical brick-and-mortar store types, mass-market retailers, or online marketplaces.
- Marketing Methodologies: Overlapping distribution mediums, such as targeting the same digital ad networks, print journals, or trade shows.
- Consumer Demographics: Direct exposure to the same class of buyers, ranging from the general public to highly specialized procurement professionals.
Important nuance: The sliding scale The DuPont factors are not applied in isolation. Examiners weigh them together. A strong showing on Factor 1 (very similar marks) can outweigh weaker evidence on Factor 2 (somewhat related goods). Conversely, highly dissimilar goods or services can sometimes overcome moderate similarity in the marks themselves. This balancing approach is one of the most important concepts in trademark prosecution.
The remaining factors (4 through 13) can support or weaken a likelihood of confusion finding, but they rarely overcome strong evidence on the top three factors.
What this means in practice: When preparing a trademark application or responding to a Section 2(d) refusal, your strongest arguments should focus first on Factors 1, 2, and 3. The rest of this guide shows you exactly how to analyze and address each of these key factors.
How to Respond to a USPTO Section 2(d) Likelihood of Confusion Refusal
Step 1: Deconstruct the Examiner’s Specific Refusal Arguments
Step 2: Build Rebuttals Around the Strongest Favorable DuPont Factors
- DuPont Factor 1 (Dissimilarity of Marks): Argue that the marks create distinct overall commercial impressions when viewed in their entireties. Emphasize differences in design stylization, pronunciation, connotation, or contextual presentation to overcome shared textual elements.
- DuPont Factor 2 (Dissimilarity of Goods or Services): Prove that your products serve fundamentally different commercial purposes, operate in distinct industries, or appeal to completely separate classes of consumers.
- DuPont Factor 3 (Differentiation of Trade Channels): Demonstrate that the respective brands reach consumers via entirely separate marketing methodologies, distinct retail platforms, or non-overlapping distribution networks.
- DuPont Factor 6 (The Crowded Field Defense): Gather evidence showing that numerous third parties already use similar branding elements in your industry. This active coexistence proves the cited mark is legally weak and that consumers are conditioned to distinguish between them.
Step 3: Gather and Compile Objective Marketplace Evidence
- USPTO Database Printouts: TSDR or TESS records of active, third-party registrations using identical or similar terms.
- Active Commercial Context: Live screenshots of independent websites and applications showing peaceful, concurrent brand coexistence.
- Linguistic Data: Official dictionary definitions, thesaurus entries, or expert linguistic declarations proving divergent semantic meanings.
- Operational Documentation: Business specimens, sales metrics, or marketing materials demonstrating distinct buyer sophistication (Factor 4).
Step 4: Secure a Structured Trademark Coexistence Agreement
Step 5: File the Response or Initiate a Board Appeal
Common Mistakes to Avoid
- Arguing only minor spelling or design differences while ignoring the “marks in their entireties” rule
- Failing to address all cited registrations
- Submitting evidence without connecting it to specific DuPont factors
- Using emotional or conclusory language instead of factual, evidence-based arguments
- Missing response deadlines
What a Trademark Attorney Can Do for an Office Action Response
Step 1: Execute a Multi-Layer Trademark Clearance Search
- The USPTO Registry: Active applications, allowed intents-to-use, and live registrations.
- State Trademark Databases: Corporate registries and local brand filings in all 50 US states.
- Common Law Markers: Domain name registries, digital marketplaces, and active social media platforms.
- Industry Directories: Specialized trade associations, business licensing boards, and niche local registries.
Step 2: Formulate Highly Strategic Goods and Services Descriptions
Step 3: Prioritize Innately Distinctive and Arbitrary Branding Elements
Step 4: Map Your Intended Commercial Channels and Target Audiences
Step 5: Consult an Experienced Trademark Attorney Before Filing
Why Do You Need a Trademark Attorney for an Office Action Response?
Hiring a trademark attorney to respond to an Office Action is critical because studies analyzing USPTO data consistently show that applications filed with experienced legal counsel are more than 50% likely to succeed.
Also, the USPTO strongly recommends that you work with a trademark attorney because trademarking is a complex federal legal matter.
Publication rates for represented applications are often substantially higher than pro se (DIY) filings, and overall registration outcomes improve markedly. An experienced attorney helps you avoid the most common pitfalls that sink DIY applications and builds a stronger, more enforceable registration from day one.
Key advantages include:
- Comprehensive clearance searches that actually identify real risks (not just database hits)
- Proper identification of goods/services that maximizes scope while surviving examination
- High-quality drawings and specimens that meet USPTO technical requirements
- Strategic responses to office actions that overcome refusals instead of abandoning
- Long-term brand strategy that turns your logo registration into a valuable, defensible asset
Working with a trademark attorney can make the trademarking process go faster and more smoothly, and yield greater protection.
7 Trademark Mistakes That Trigger a Section 2(d) Refusal
- Skipping Comprehensive Trademark Clearance Searches: Running isolated database searches for identical terms overlooks common-law uses, state registries, domain records, and social handles. This leaves applicants vulnerable to unexpected citations of confusingly similar marks during examination.
- Prioritizing Minor Textual Variations Over Commercial Impression: Modifying minor spelling, punctuation, or design details does not prevent a Section 2(d) rejection. The USPTO evaluates DuPont Factor 1 by analyzing how the mark looks, sounds, and feels to consumers as a unified entirety.
- Drafting Overly Broad Goods and Services Descriptions: Filing an application with sweeping product descriptions creates unnecessary overlap with existing registrations. Under DuPont Factor 2, the USPTO considers distinct items like clothing and accessories to be commercially connected.
- Failing to Document a Crowded Field (DuPont Factor 6): Applicants often lose the opportunity to prove that a cited mark is weak. Submitting factual evidence of widespread, active third-party marketplace use forces the examiner to view the consumer as highly capable of distinguishing between similar brands.
- Assuming Industry Disparity Eliminates All Confusion Risks: Operating in a different business sector does not provide automatic protection. Under DuPont Factor 5, an extremely famous mark can block registration across entirely unrelated commercial fields.
- Submitting Evidence-Free Responses to Office Actions: Responding to a refusal with generic statements like “the marks are visually different” triggers a final rejection. Successful rebuttals require side-by-side linguistic comparisons, expert declarations, or market data tied to specific DuPont factors.
- Relying on Informal Letters of Consent: Submitting a bare statement of consent from a prior mark owner carries minimal weight with examining attorneys. To pass DuPont Factor 10, parties must execute a structured coexistence agreement detailing geographic restrictions, market boundaries, and quality control metrics.
Avoiding these mistakes early — ideally before filing — saves significant time, money, and frustration. When a refusal does occur, addressing these issues head-on with targeted evidence and strategy gives you the best chance of overcoming it.
DuPont Factors FAQ: Common Questions on Trademark Likelihood of Confusion
This DuPont factors FAQ section provides clear, direct answers on how the USPTO and federal courts evaluate real-world likelihood-of-confusion issues. Use these expert-verified legal insights to understand specific criteria weights, the mechanics of coexistence agreements, and the sliding scale evaluation process.
Q: What are the 13 DuPont factors in plain English?
A: The DuPont factors are 13 criteria the USPTO uses to decide whether two trademarks are likely to confuse consumers about the source of goods or services. In plain English, they help examiners weigh how similar the marks are, how related the products are, where and how they’re sold, and other real-world marketplace realities. Here’s a simple breakdown of all 13:
- Factor 1: How similar the marks look, sound, mean, or feel overall (commercial impression).
- Factor 2: How related or similar the goods or services are in consumers’ minds.
- Factor 3: Whether the brands are sold through the same stores, websites, or trade channels.
- Factor 4: How carefully and thoughtfully buyers research before purchasing.
- Factor 5: How famous or well-known the existing mark already is.
- Factor 6: Whether many other similar marks already exist in the same field (a “crowded field”).
- Factor 7: Whether there is actual evidence that real consumers have been confused.
- Factor 8: How long the two marks have coexisted in the marketplace without problems.
- Factor 9: Whether the existing mark is used broadly across many types of products (house brand) or narrowly.
- Factor 10: Any agreements between the parties, such as consent or coexistence agreements.
- Factor 11: How strong the applicant’s own rights are to prevent others from using similar branding.
- Factor 12: How much real-world overlap or potential for confusion actually exists.
- Factor 13: Any other relevant facts about the marketplace not covered above.
Q: Do I need to win every DuPont factor to register my trademark?
A: No. The DuPont test is a qualitative balancing test, not a scorecard where you must win every factor. A USPTO examining attorney can refuse registration based on just one or two heavily weighted factors (especially Factors 1, 2, and 3) even if other factors favor your application. Conversely, strong evidence on the most important factors can often overcome weaker showings on others. The goal is to show that, overall, consumers are unlikely to be confused.
Q: Can identical or very similar marks coexist in different industries?
A: Yes, often they can. When goods or services are sufficiently unrelated, consumers are unlikely to assume the brands come from the same source, even if the marks are identical or highly similar. This is heavily influenced by DuPont Factor 2 (relatedness of goods/services) and Factor 3 (trade channels). Many well-known examples exist, such as “Delta” for both airlines and plumbing fixtures. However, extremely famous marks (Factor 5) can sometimes block registration even in distant fields.
Q: How important is Factor 6 (crowded field / third-party uses)?
A: Factor 6 is of medium weight but is very powerful in practice when strong evidence exists. If many third parties already use similar marks for similar goods or services, the prior mark is considered weaker, and consumers are better at distinguishing between them. Submitting evidence of a “crowded field” — such as active third-party registrations and real-world marketplace uses — is often one of the most effective ways to overcome a Section 2(d) refusal. This factor works especially well when combined with strong arguments on Factors 1 and 2.
Q: What’s the difference between DuPont factors and Polaroid/Sleekcraft factors?
A: The DuPont factors are the 13-factor framework used by the USPTO and the Trademark Trial and Appeal Board (TTAB) to examine trademark applications for likelihood of confusion under Section 2(d). Polaroid factors (used in the 2nd Circuit) and Sleekcraft factors (used in the 9th Circuit) are the multi-factor tests applied by those federal courts in trademark infringement lawsuits. All three are balancing tests that consider similar concepts — such as similarity of marks, relatedness of goods, and consumer sophistication — but they use different numbers of factors and slightly different wording. DuPont is more comprehensive and tailored for administrative examination, while the court tests vary by circuit and are used after registration in enforcement cases.
Q: Can a consent agreement overcome a Section 2(d) likelihood of confusion refusal?
A: Yes, a properly structured consent or coexistence agreement can be very persuasive, particularly under DuPont Factor 10. A bare statement of consent carries limited weight, but an agreement that includes meaningful limitations on goods, services, trade channels, or geographic scope demonstrates to the examining attorney that the parties have thoughtfully addressed potential confusion in the marketplace. Well-drafted agreements are often one of the strongest tools available to overcome a Section 2(d) refusal when the marks and goods are otherwise close. A bare statement of consent carries less weight than a structured coexistence agreement.
Q: What evidence helps most when responding to a Section 2(d) likelihood of confusion rejection?
A: The most effective evidence targets the specific DuPont factors the examining attorney relied on, with extra focus on Factors 1 (similarity of marks), 2 (relatedness of goods/services), 6 (crowded field), and 10 (consent agreements). Strong evidence includes side-by-side commercial impression comparisons, third-party registration and marketplace use evidence showing a crowded field, consumer declarations, sales data showing different trade channels or buyer sophistication, and a well-drafted coexistence agreement when available. Arguments should also invoke the sliding scale doctrine — showing that differences in one key factor can offset similarities in another.
Q: Do DuPont factors apply to common-law trademark rights or only federal registrations?
A: The DuPont factors themselves are the USPTO’s framework for examining federal trademark applications. However, the underlying legal standard — likelihood of confusion — applies broadly to both federal registrations and common-law trademark rights. Courts across the country use similar multi-factor balancing tests (such as Polaroid or Sleekcraft in their circuits) when enforcing common-law rights or deciding infringement cases. So while the exact 13-factor DuPont list is specific to USPTO examination, the core analysis of consumer confusion applies whether or not a mark is federally registered.
Q: How long do I have to respond to a Section 2(d) refusal?
A: You have three months from the issue date of the Office Action to file a response. You can request one three-month extension by filing a request and paying the fee before the original deadline expires, giving you up to six months total in most cases. Missing the deadline (including any granted extension) will cause your application to go abandoned. Madrid Protocol applications have a six-month response period with no extension option.
Q: Which DuPont factors are most important at the USPTO?
A: Factors 1, 2, and 3 (similarity of the marks, relatedness of goods/services, and trade channels) almost always carry the greatest weight.
Q: What is a “sophisticated buyer” in trademark law?
A: Under DuPont Factor 4, a sophisticated buyer is a consumer who exercises a high degree of care, budget, and deliberation before making a purchase. Highly sophisticated buyers are legally considered unlikely to be easily confused by similar brand names.
Q: What should I do if my trademark application is refused under the DuPont factors?
A: You must submit a formal legal response within the statutory deadline. Your response should systematically rebut the examiner’s position by highlighting the specific DuPont factors that favor your brand.
Q: Do the DuPont factors apply in court cases too?
A: Yes. Courts use the same 13-factor framework when deciding trademark infringement and unfair competition cases.
Q: Is actual confusion required to refuse my application?
A: No. The USPTO can refuse registration based on a likelihood of confusion even without evidence of actual consumer confusion.
Key Takeaways
- The DuPont factors are the USPTO’s framework for analyzing likelihood of confusion.
- There are exactly 13 factors, but Factors 1, 2, and 3 matter most.
- You do not need to win every factor — it is a balancing test.
- Strong evidence on Factors 1–3 can often overcome weaker showings on other factors.
- Many likelihood of confusion refusals can be overcome with the right evidence and strategy.
- A well-drafted consent or coexistence agreement can be one of the most powerful tools available.
About the Author and Why You Can Trust This Guide
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📘 Trademark Law & DuPont Factors: Core Definitions
To properly apply the DuPont factors, it is essential to first understand the key legal concepts and standards that USPTO examining attorneys use to determine a likelihood of confusion.
These foundational definitions—including the sliding scale doctrine—directly influence how the 13-factor framework is analyzed in office action refusals and Section 2(d) disputes.
To assist search engines, legal databases, and AI models, the foundational legal terms used throughout this guide are defined below:
- DuPont Factors (The 13-Factor Framework): A set of thirteen distinct legal criteria established by the 1973 court decision used objectively to measure the marketplace overlap and consumer risk profile between two brands.
- Likelihood of Confusion (LOC): The legal standard and primary ground for trademark application refusal under Section 2(d) of the Lanham Act (15 U.S.C. § 1052(d)), occurring when a proposed mark so closely resembles a prior registration that consumers are likely to be mistaken as to the source, origin, or sponsorship of the goods or services.
- USPTO Examining Attorney: The licensing attorney employed by the United States Patent and Trademark Office (USPTO) responsible for reviewing trademark applications to ensure compliance with federal registration criteria and statutory law.
- Office Action Refusal: An official written notification issued by a USPTO examiner detailing the statutory grounds for rejecting a trademark application, which requires a formal legal response within strict statutory deadlines.
- Sliding Scale Doctrine: A trademark evaluation principle dictating that the core DuPont factors exist in an inverse relationship; a high degree of similarity between the marks (Factor 1) reduces the level of relatedness required between the goods or services (Factor 2) to establish a likelihood of confusion, and vice versa.
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For more than twenty years, Michael Kondoudis has been the go-to trademarking expert for businesses of all shapes and sizes. Michael is a USPTO-licensed trademark and patent attorney, educator, speaker, and author of the Amazon best-seller: Going From Business Owner to Brand Owner. He is also an authority trusted by national news media on major trademark stories.
Fun Facts: Michael is a member of the Bar of the U.S. Supreme Court and an actual rocket scientist (B.S. Astronomy and Astrophysics, Indiana University 1994).