Likelihood of Confusion

Similar Marks Can Be Confusingly Similar in the Eyes of the Consumer

Every business owner choosing a brand name or logo should understand the trademark concept of likelihood of confusion. This is the legal standard U.S. courts and the U.S. Patent and Trademark Office (USPTO) use to decide if two trademarks are too similar. If consumers would likely confuse the source of goods or services bearing two similar marks, then a conflict exists under trademark law. The underlying reason that trademark law prevents such confusion is to ensure consumers get accurate information about a product’s source. The law prevents such confusion primarily to protect consumers from being misled, while also safeguarding fair competition and business goodwill.

The principle of blocking confusingly similar marks has roots in 19th-century common law. Early trademark cases grew out of the law of unfair competition, particularly the doctrine of passing off, which essentially forbids one trader from misrepresenting their goods as someone else’s. As an English court famously stated in 1842, “A man is not to sell his own goods under the pretence that they are the goods of another man”. Perry v. Truefitt (1842) 6 Beav. 66, 73.

The fundamental goal is to keep the marketplace honest and efficient for buyers. Trademarks (brand names, logos, etc.) serve as source-identifiers: they tell you who made a product or provides a service. When you see a familiar brand on a package, you assume it comes from the same source as all other products with that brand (think of Nike shoes, Hilton hotels, and Toyota vehicles). This confidence lets consumers make quick, informed choices. In economic terms, a distinctive trademark reduces consumer search costs. Shoppers don’t have to investigate the origin or quality of every product anew; the brand name carries that information and the company’s reputation. Businesses, in turn, are motivated to maintain quality and consistency, since their name is what customers rely on. In short, strong, non-confusing trademarks make shopping easier and reward companies for building goodwill with consumers.

What Is “Likelihood of Confusion”?

Under U.S. trademark law, "likelihood of confusion" refers to the probability that consumers will be misled into believing that two different products or services come from the same source. The core question is whether an ordinary prudent consumer in the marketplace would reasonably expect the two marks (e.g. brand names or logos) to come from one company or affiliated companies. If such consumer confusion is likely, the law deems the marks confusingly similar. The law does not require proof that consumers are actually confused; it only requires showing that confusion is likely to happen.

For example, imagine one coffee shop is named “Bean Bazaar” and another coffee shop opens nearby as “Bean Bizarre”. Even though the second name is spelled differently, they are phonetically similar and offer the same services. Customers could easily assume the two cafes are related. They might think the new cafe is a second location or a spin-off of “Bean Bazaar.” In this scenario, there is a strong possibility that consumer confusion would occur.

Why Likelihood of Confusion Matters

Likelihood of confusion is the linchpin of trademark infringement cases. Under the federal Lanham Act (the U.S. Trademark Act), a trademark owner can stop others from using a mark if that use “is likely to cause confusion or mistake or to deceive” consumers about the source of the goods. In an infringement lawsuit, the plaintiff must prove that the defendant’s allegedly infringing mark is likely to confuse consumers. If the plaintiff succeeds, the court can order the infringer to stop using the mark and potentially pay damages. If the trademark owner can show instances of actual consumer confusion, the law recognizes that damage to the brand may already be done.

Courts commonly articulate the test as whether the buying public would likely believe the two products or services came from the same source. For instance, in Bean Bazaar - Bean Bizarre example, a court would ask whether an average customer exercising ordinary caution think these products come from the same company? If yes, the trademark owner has a strong infringement case. If no, then infringement will not be found.

Trademark Applications and USPTO Confusion Refusals

Likelihood of confusion also matters when you apply to register a trademark. The USPTO examining attorney will perform a trademark search of existing marks. If the examiner finds a previously registered mark (or pending application) that is confusingly similar to your proposed mark, your application will be refused on likelihood of confusion grounds. This is often called a “Section 2(d) refusal,” referring to the section of the Lanham Act that bars registration of a mark that is likely to cause confusion with an existing mark. You’ll receive an office action explaining the conflict and will have to argue why your mark is not confusingly similar or else your registration will not go through.

For example, if you try to register “Omega Electronics” and there’s an active trademark registration for “Omega Electric” selling related products, the Trademark Office will issue a likelihood of confusion refusal. Under 15 U.S.C. § 1052(d), no new mark can be registered if it “so resembles a mark registered in the Patent and Trademark Office… 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.” In essence, the USPTO is trying to protect consumers and senior trademark owners by preventing look-alike or sound-alike marks from getting on the federal register.

Just like courts, the USPTO uses a multi-factor analysis to assess proposed trademarks. These are known as the DuPont factors, from the case In re E.I. du Pont de Nemours & Co. 476 F.2d 1357 (CCPA 1973). The examining attorney will compare the marks in appearance, sound, meaning, and commercial impression, evaluate the relatedness of the goods or services, and consider other relevant factors that might indicate potential confusion. If, after weighing the factors, the examiner believes confusion is likely, the application is denied. This is why conducting a thorough trademark search before filing an application and before choosing a trademark and brand is so important. Prudence can save you from investing in a name that the USPTO or courts would deem too close to an existing mark.

How Do You Determine Likelihood of Confusion?

To decide whether confusion exists between two marks, courts and the USPTO use a multi-factor test. There is no single bright-line rule. Several important factors relating to trademark confusion are evaluated. A famous example is the Sleekcraft factors, originating from the case AMF, Inc. v. Sleekcraft Boats, 599 F.2d 341 (9th Cir. 1979), which set out a framework that many courts follow. Most U.S. jurisdictions have a similar list (the Polaroid factors in the Second Circuit , the Lapp factors in the Third Circuit, etc.), but all share common considerations. The USPTO’s analysis under the DuPont factors is largely similar to the court tests. It is critical to note that not all factors will be relevant in every case, and no one factor is dispositive. Decision-makers will look at the overall picture of whether the consumer confusion is likely.

Here are the primary factors (the “Sleekcraft” factors) that are typically considered in a confusion analysis:

• Strength of the senior mark – How distinctive or well-known is the older mark? (Stronger marks get broader protection.)
• Similarity of the marks – How similar are the two marks in appearance, sound, meaning, and overall impression?
• Similarity of the goods or services – Are the companies’ products or services related or in competition?
• Overlap in trade or marketing channels – Do the goods travel in the same marketing channels or distribution channels to reach consumers?
• Evidence of actual confusion – Has there been real-world confusion by consumers?
• Defendant’s intent – Did the junior user intentionally copy or seek to benefit from the senior’s reputation?
• Purchaser care and sophistication – How careful or knowledgeable is the typical consumer of these products?
• Likelihood of expansion – Will the senior user likely expand into the junior user’s product line (or vice versa), increasing future conflict?

These factors are a guide rather than a checklist. Next, we’ll explore each of the major factors in turn, along with examples and key cases, to see how they affect the confusion analysis.

Strength of the Mark (Distinctiveness)

Trademarks vary in strength. A unique, distinctive mark has a wider scope of trademark protection, while a common or weak mark gets a narrow scope. The law categorizes marks along a spectrum of distinctiveness:

• Generic – Common names for the product itself (e.g. calling a coffee shop “Coffee Shop”). Generic terms can never function as trademarks and receive no protection.
• Descriptive – Marks that describe a quality or feature of the goods (e.g. “Speedy Car Wash” for a car cleaning service). Descriptive marks are not protectable unless they acquire distinctiveness (secondary meaning); i.e. the public comes to recognize the term as identifying a single source, not just the description. Establishing secondary meaning through extensive use, advertising, etc. can make a descriptive mark protectable.
• Suggestive – Hints at or suggests some attribute of the goods, requiring consumer imagination (e.g. “Netflix” suggesting internet flicks). Suggestive marks are inherently distinctive and protectable because they aren’t directly descriptive.
• Arbitrary – Common words used in an unrelated context: e.g. “Apple", since computers have no logical connection to fruit. Arbitrary marks are distinctive and strong.
• Fanciful – Completely made-up words, such as “Xerox” for copiers. These are highly distinctive and generally the strongest type of mark.

A strong mark (arbitrary, fanciful, or well-known with secondary meaning) will typically enjoy greater protection, meaning it can stop others from using even somewhat similar marks on related goods. A weak mark (e.g., descriptive without secondary meaning, or a mark used by many others in the field) will have a harder time claiming exclusivity. For example, a hypothetical brand “National Electronics” would be considered weak if many companies use “National” in their names. By contrast, a unique brand like “Xybernaut” for electronics is inherently strong. In one case, a cleaning service branded “Maid in America” (a descriptive wordplay) was deemed too descriptive and lacking secondary meaning, and the owner failed to prove infringement on that basis. The bottom line: the more distinctive your mark, the easier it is to prevent confusingly similar imitations.

Similarity of the Marks (Sight, Sound, Meaning)

One of the most important factors in any likelihood of confusion case is how similar the two marks are. To determine this, the marks are compared in their entirety, focusing on their appearance, sound, connotation (meaning), and overall commercial impression. Minor differences often do not suffice to avoid confusion if the overall impression is similar.

When evaluating similarity, courts and the USPTO consider the marks as consumers would encounter them in the marketplace. This means even if two marks have slight spelling differences or additional words, they could still be deemed essentially the same mark in the minds of consumers. Pronunciation is especially influential: marks that sound alike can confuse listeners even if spelled differently. For instance, “SUN Bank” and “Son Bank” would be nearly indistinguishable when spoken aloud. The same goes for marks with similar meanings or images (connotation). If one brand is called “Valiantheart Beer” and another is “Braveheart Ale”, the shared concept of courage could create a similar mental image or impression for consumers.

Courts will typically compare the marks side by side on these aspects:

• Visual similarity – e.g. the lettering, logo design, or length of the words.
• Aural similarity – how the names sound when spoken (rhythm, syllables, pronunciation).
• Meaning – whether the marks share a similar meaning or concept.
• Overall impression – the general feeling or memory a consumer would take away (even if they don’t recall the exact spelling).

If the dominant portion of the marks is the same, confusion is more likely. For example, adding a common suffix or changing one letter usually won’t avoid confusion: “Magnavox” vs. “Multivox”, “Travel Planner” vs. “The Travel Planner”, or “Maternally Yours” vs. “Your Maternity Shop” were all found to be confusingly similar pairs. In the Maternally Yours case, a maternity clothing retailer named Maternally Yours stopped a competitor from using Your Maternity Shop, even though the phrasing was slightly different, the court noted the same words just rearranged still misled customers. Maternally Yours, Inc., v. Your Maternity Shop, Inc., 234 F.2d 538 (2d Cir. 1956). Likewise, simply adding a small prefix or suffix might not change the mark’s identity in consumers’ minds. If someone tried to sell coffee under the name “Starbucks Café” versus the famous “Starbucks”, the extra word doesn’t prevent consumer perception of a link to the Starbucks brand.

Relatedness of Goods or Services (Proximity of Products and Markets)

Even if two marks are very similar, confusion might not occur if they are used on completely different types of goods or services. This factor looks at how related the goods or services are and whether they occupy the same or overlapping market. The basic idea: the more the products compete or are marketed in similar channels, the more likely consumers will assume a common source.

Consider these scenarios:

• Direct Competitors: If two companies use similar marks on competing products or services in the same industry, confusion is highly likely. A customer seeing two similar snack brands on the same grocery shelf could easily mix them up.
• Related but Not Identical: If the products are different but related goods (say, one is a clothing brand and the other is a footwear brand), confusion can still occur, but other factors will play a larger role. Consumers might think the companies are affiliated or one has expanded its product line.
• Totally Unrelated: If the businesses are in entirely separate realms, confusion is unlikely. For example, using the same name for a coffee shop and a computer software company usually wouldn’t confuse consumers, because people do not expect those very different goods or services to come from the same source.

A classic example: “Delta” is used as a mark by both an airline and a faucet manufacturer, but the goods and services contexts are so different that consumers don’t assume a connection. In contrast, when the fast-food giant McDonald’s objected to a hotel chain’s plan to open budget hotels under the name “McSleep”, a court agreed that consumers might assume McDonald’s (famous for the “Mc-” family of brands like McNuggets, McMuffin, etc.) was expanding into hotel services. Quality Inns International, Inc. v. McDonald's Corp., 695 F. Supp. 198 (D. Md. 1988). The federally registered McDonald’s mark was so well-known and strong that even a different service (motels) could trigger an association. This shows that a very famous mark have more brand reach across goods and services. People could believe McDonald’s had a hand in anything starting with “Mc.” So, the more closely related the product lines or the more expansive the senior brand’s reputation, the more a similar mark will create confusion.

Additionally, this factor examines the overlap in marketing channels and customer base. If both companies advertise in the same magazines, sell in the same department store chains, or target the same demographic, a consumer could encounter both products in the same context and mistakenly think they are connected. On the other hand, if one product is sold only in upscale boutiques and the other in discount stores, or one is B2B sales and the other retail, the separation may reduce confusion.

In sum, the closer the marketplace proximity, the greater the chance that consumers will assume a single source. Businesses should be cautious if they choose a name similar to another company that’s even tangentially related to their line of business, especially if that company might bridge the gap and enter your market.

Evidence of Actual Confusion

While a plaintiff doesn’t need to show any instances of real-world confusion to win an infringement case, any direct evidence of actual confusion can be extremely persuasive. Actual confusion means customers truly have been misled. For example, mistaking one brand for another, misdirected phone calls or emails, or survey results showing a significant number of consumers believed the two companies were connected. If such evidence exists, it strongly supports the argument that the similarity of the marks constitutes likelihood of confusion. As one source explains, proof that the average reasonably prudent consumer is confused is powerful evidence of infringement.

Courts often say actual confusion is the best evidence of likelihood of confusion. However, it’s important to remember that it is not required to prove a case. Many infringement cases are decided without any documented instances of confused consumers. For example, a company might sue shortly after the junior user begins using the mark and there may not have been time for actual confusion to manifest. In such cases, the court will rely on the likelihood factors, expert testimony, and consumer surveys rather than waiting for customers to be misled in the real world.

In practice, companies sometimes commission consumer surveys in litigation to gauge actual confusion. These surveys ask a sample of target customers questions to see if they believe two products come from the same source. While survey evidence can be direct evidence of confusion, its reliability can be contested, and a poor survey can even hurt the plaintiff’s case. Nonetheless, actual confusion remains a crucial factor: if you receive reports that customers are truly mixing up your product with another brand, that’s a red flag that your marks are too close.

If a plaintiff is able to show actual confusion, it can tip the scales. Even a few incidents, such as a shopper returning a product to the wrong company, or consumers commenting “Oh, I thought your brands were the same”, can carry considerable weight. Large-scale evidence like survey results or a pattern of mix-ups is even more compelling. Conversely, the absence of any known confusion after a long time of coexistence might suggest that confusion is less likely. The concept of long-term co-existence without any consumer confusion is also a factor considered under the likelihood of confusion analysis.

The Defendant’s Intent in Adopting the Mark

Trademark law also looks at the intent of the junior user (the alleged infringer). If the defendant intentionally copied or chose a mark to create confusion with the senior user’s mark, courts view that as evidence that confusion is likely. After all, if someone tries to ride on the coattails of an established brand, it implies they believe consumers will mistake the two and that they will benefit from that misassociation. Deliberate adoption of a similar name, especially with evidence like internal emails or mimicry of logos/packaging, can strongly favor the trademark owner’s case.

For example, in the earlier Maternally Yours case, the defendant opened a store called “Your Maternity Shop” just blocks away from the plaintiff’s Maternity Shop, with knowledge of the plaintiff’s business. The defendant even imitated the plaintiff’s signage style, packaging, and advertising format: “all with the obvious intention of misleading the public and diverting trade from the plaintiff.” The court noted this bad faith and found it indicative that confusion was intended and likely. Evidence of defendant’s intent to cause customers to associate the two companies strongly weighs toward finding likelihood of confusion.

It’s worth noting that intent is not a required element for infringement. A well-meaning business can inadvertently infringe if their mark is confusingly similar, even if they had no knowledge of the other mark. However, when defendant’s mark choice is made in bad faith (e.g., a former employee of Company A starts Company B with a nearly identical name to siphon customers), courts will not hesitate to infer that confusion was not only likely but the very goal. On the flip side, if a defendant can show they acted in good faith, had no knowledge of the plaintiff’s mark, and picked their mark independently, that won’t necessarily avoid liability, but it will weigh against a finding of likelihood of confusion and may influence remedies. Defendant's intent mainly helps the court gauge how the marks came to be similar; a bad intent usually makes the court more skeptical of the junior user’s arguments.

Consumer Sophistication and Degree of Care

Not all consumers are alike. The law recognizes that the likelihood of confusion can depend on the level of care or attention the typical buyer exercises for a given product. If the relevant consumers are very careful, highly educated, or making expensive, important purchases, they are less likely to be confused by similar marks. Conversely, if the goods are low-cost items bought on impulse by the general public, the risk of confusion goes up because buyers aren’t researching or deliberating over the purchase.

Courts typically apply the standard of a “typical purchaser exercising ordinary caution”. For everyday inexpensive products (like a snack food), an average buyer might not take much time to discern the brand. If two bags of chips have similar branding, a hurried shopper could grab the wrong one. Here, even slight similarities can confuse consumers who aren’t paying close attention.

On the other hand, consider very expensive or specialized goods, like industrial machinery or luxury real estate. Buyers of those tend to research thoroughly, often know the market players, and are more sophisticated. They are less likely to be misled by similar trademarks because they’ll notice subtle differences. For example, a company selling $50,000 laboratory equipment under the name “LabTech Innovations” might not be confused with “LabTech Instruments” if their customers are procurement experts who investigate each vendor. The degree of purchaser care is higher in that market. As one case noted, if the target buyers are careful, sophisticated purchasers, even marks that are somewhat alike may not cause confusion.

In evaluating this factor, courts consider the typical price of the goods, the conditions of purchase, and the buyer’s expertise. The law expects the purchaser of expensive, specialized goods and services to exercise a high degree of care, reducing the likelihood they’d be confused by mere trademark resemblance.

Other Factors and Special Considerations

Beyond the primary factors above, there are other factors and nuances that can influence a likelihood of confusion analysis. Trademark law is flexible, and not all factors carry equal weight in every case. Here are a few additional considerations:

• Likelihood of Expansion (“Bridging the Gap”): If the two companies aren’t direct competitors now, will the senior user likely expand into the junior user’s market? If a trademark owner can show it is likely to expand its product lines or services into the area of the junior user, this increases the chance of confusion. For example, if a well-known coffee shop brand hasn’t started selling packaged coffee beans yet, but it’s reasonable consumers would expect them to (given the brand’s growth), a newcomer selling coffee beans under a similar name could cause confusion. Consumers might assume the senior brand bridged the gap and is now offering those goods.
• Fame of the Prior Mark: A famous or strong mark casts a long shadow. As seen with the McSleep example, famous brands are given a wide berth; people might think a famous brand is behind a diverse range of goods. The Dupont factors explicitly include the fame of the prior mark as a consideration. A very famous trademark like Coca-Cola or Nike will be infringed by a similar mark even on unrelated goods, because the public could think of brand extensions or licensing. This factor ties into mark strength but specifically looks at consumer recognition and reach of the senior mark.
• Number of Similar Marks in Use: If the mark is in a "crowded field" with many similar marks, consumers may learn to distinguish slight differences. For instance, if many companies use the term “United” or “Global” for similar services, another entrant with “United XYZ” might not uniquely point to one source in consumers’ minds, potentially lessening confusion, and also weakening each individual mark’s strength. On the other hand, if your mark is unique in your industry, another company’s use of a similar name is more likely to confuse. The USPTO’s DuPont factors include looking at the number and nature of similar marks already in use on similar goods.
• Length of Coexistence Without Confusion: If two marks have coexisted for a long time without evidence of actual confusion, that can indicate that perhaps confusion is not likely. For example, in one trademark appeal, a company sought to register “ANYWEAR” for footwear despite another brand “ANYWEAR by Josie Natori” existing for clothing. The Trademark Trial and Appeal Board noted an “unusual situation”; the two marks had coexisted in the marketplace for five years without any known incidents of confusion. In re Strategic Partners, Inc., 102 USPQ2d 1397 (TTAB 2012). This history helped persuade the Board to reverse a refusal and allow the registration of the ANYWEAR mark. Such cases are rare, but they show that if real-world experience demonstrates consumers aren’t mixing up the marks, a decision-maker might conclude there is no likelihood of confusion despite similarities. Keep in mind, this tends to be fact-specific and usually requires strong evidence of peaceful coexistence.
• Quality of the Junior User’s Goods: Some courts consider whether the junior user’s goods are inferior in quality. The reasoning is that if lower-quality products are sold under a similar mark, they could tarnish the senior user’s reputation, so the law should intervene to prevent confusion. For instance, a famous restaurant finds a local diner using a similar name and serving terrible food – the harm to the famous brand’s goodwill if people confuse them is a concern.
• Consumer Perception and Overall Context: Ultimately, all these factors feed into what is essentially a single question: what is the consumer’s perception in the real world? Everything is determined based on the facts of each case. There is no mechanical test. Courts often emphasize that the multi-factor test is not a scorecard. It’s possible for a court to find no likelihood of confusion even if two marks are somewhat similar and the goods related, if other factors strongly point away from confusion. For example, if two companies use similar marks but do business in completely different regions with completely different consumer bases, and both have distinct branding styles, a court might find that confusion is unlikely in context. Relevant factors can vary: one case might hinge largely on the similarity of marks, while another might be decided mostly on the basis of market separation or the sophistication of buyers.

With all these factors, no single factor is dispositive. A strong showing on a few factors can outweigh others. The analysis is holistic: it looks at the totality of circumstances. This flexible approach is why advice from an intellectual property attorney or trademark attorney can be invaluable. They can assess how the factors stack up in your particular situation and compare it to past cases.

Conclusion

A familiarity with the likelihood of confusion standard is useful in the brand selection process. Business owners with a working knowledge of the standard also have a much better chance of avoiding trademark infringement. The key takeaways are: choose a distinctive mark, do your homework with a thorough trademark search, and be mindful if there are other brands in your industry so that you can anticipate and identify potential consumer confusion issues. The multi-factor analysis may seem complex, but it essentially asks the question "Will consumers likely be confused or think there’s an association between two brands?"

If you’re unsure about a new brand name or you receive a cease-and-desist letter alleging your mark is confusingly similar to another, consider consulting a trademark attorney. An experienced attorney can analyze the alleged infringement and advise you of your best course of action. Contact our office for a free consultation to discuss your trademark matters.

© 2025 Sierra IP Law, PC. The information provided herein does not constitute legal advice, but merely conveys general information that may be beneficial to the public, and should not be viewed as a substitute for legal consultation in a particular case.