If you have received a trademark Office Action citing a likelihood of confusion, you are not alone. It is the single most common reason the USPTO rejects trademark applications, and it catches a lot of people off guard.

The refusal usually comes as a surprise. You picked a name you thought was unique. You maybe even did a quick Google search and did not see anything obvious. Then a few months after filing, you get a letter from the USPTO telling you your mark is too similar to someone else’s.

Here is what you need to know: a likelihood of confusion refusal is not a denial. It is an objection. And objections can be overcome if you understand how the analysis works and where you have room to push back.

This guide breaks down the factors the USPTO uses to evaluate confusion, which ones carry the most weight, and how to think about building a response.

What Does Likelihood of Confusion Actually Mean?

Under Section 2(d) of the Lanham Act, the USPTO cannot register a trademark if it is likely to be confused with an already-registered mark. Notice that the standard is not actual confusion. It does not require proof that someone was actually misled. It only requires that confusion would be likely.

The Examining Attorney assigned to your application searches the USPTO database before approving it. If they find a registered mark that looks, sounds, or feels similar to yours and covers related goods or services, they will issue an Office Action and put your application on hold until you respond.

The legal framework for making that call comes from a 1973 case called In re E.I. DuPont de Nemours & Co. The DuPont factors, as they are known, are the thirteen criteria the USPTO and federal courts use whenever likelihood of confusion is at issue. You do not need to memorize all thirteen. But you do need to understand the ones that matter most.

The Factors That Matter Most

1. How Similar Are the Marks?

This is the most important factor. The Examining Attorney looks at the marks in their entireties and evaluates three things: how they look, how they sound, and what they mean. You do not get credit for arguing that the marks are different in just one of those three areas. All three are considered together.

Two marks can look completely different on paper and still be considered confusingly similar if they create the same overall commercial impression. The question is whether an average consumer, seeing the marks separately over time, would likely be confused about the source of the goods or services.

Where you have room to argue: Be specific. Point out concrete differences in appearance, pronunciation, and meaning. Generic statements like “the marks look different” are not persuasive. Walk through each element and explain precisely why the overall impression is distinct.

2. How Related Are the Goods or Services?

Even if two marks are quite similar, confusion is much less likely if the goods or services have nothing to do with each other. On the flip side, even marks that are somewhat different can be found confusingly similar if they are used on closely related or complementary goods or services.

The USPTO does not need to find that the goods are identical. It just needs to find that consumers might reasonably assume they come from the same source.

Where you have room to argue: If your goods or services genuinely serve different markets or different purposes, make that case clearly. Explain the distinction in plain terms, focusing on why a consumer would understand they are dealing with two different businesses.

3. Where Are the Goods or Services Sold?

If two brands operate in completely different sales channels, the chance that a consumer encounters both and gets confused drops significantly. A product sold exclusively through high-end specialty retailers and a product sold through discount grocery stores are unlikely to cross paths in a way that causes confusion.

Where you have room to argue: This works best when the difference in channels is real and documented. If both marks operate primarily online or through general retail, this argument is harder to sustain.

4. Who Is Buying and How Carefully?

A business purchasing enterprise software after a three-month procurement process is a fundamentally different buyer than a consumer grabbing something off a grocery shelf. The more deliberate and informed the typical purchaser, the less likely they are to be confused by similar marks.

Where you have room to argue: If your goods or services are expensive, specialized, or purchased primarily by professionals or businesses, lean into this. The more care typically involved in the purchase decision, the more this factor cuts in your favor.

5. How Strong Is the Cited Mark?

A famous or highly distinctive mark gets broader protection. A weak or descriptive mark gets a much narrower scope. If the mark the USPTO cited against you is not particularly strong, or if there are a lot of similar marks already registered in your space, that matters.

Where you have room to argue: Search the USPTO database for third-party registrations that use similar terms in the same industry. A crowded field of similar marks is evidence that the term is weak and commonly used, which narrows the cited mark’s reach and strengthens your position.

6. Has There Been Any Actual Confusion?

Evidence that real consumers have actually been confused is compelling. But the absence of actual confusion is not fatal to the USPTO’s position, especially if the marks have not coexisted in the marketplace for long.

Where you have room to argue: If your mark has been in use alongside the cited mark for a meaningful period of time without any reported confusion, document it. A declaration from you explaining the coexistence, combined with evidence of marketplace use, can support this argument.

Before You File: How to Avoid This Problem Entirely

The best way to deal with a likelihood of confusion refusal is to not get one. That starts with a proper clearance search before you file.

A clearance search is not just a quick check of the USPTO database for exact matches. It means looking for marks that are phonetically similar, visually similar, or create a similar commercial impression in the same or related classes of goods or services. It also means checking common law use, domain names, and social media.

If a conflict is identified before filing, you can make an informed decision about whether to proceed, modify the mark, or choose a different name altogether. That is a much better position than discovering the problem six months after you have already invested in branding, packaging, and marketing.

If You Already Have a Registration: What to Watch For

Likelihood of confusion is not just a filing issue. It comes up on the other side too, when someone else files a mark that conflicts with yours.

Once your trademark is registered, you have a responsibility to monitor for conflicting marks and take action when appropriate. Every registered mark goes through a publication period before registration is finalized. During that window, you have the opportunity to oppose the registration if you believe it conflicts with your mark.

If you are not monitoring new filings, you can miss that window entirely. And the longer a conflicting mark is in use, the harder it becomes to enforce your rights against it.

How to Build a Response That Actually Works

A response to a likelihood of confusion refusal needs to be systematic. Picking one factor and hoping for the best is not a strategy. Here is how to approach it:

• Work through the marks side by side. Address appearance, sound, and meaning separately and specifically.
• Address the goods and services directly. Do not assume the Examiner understands your industry. Explain the distinction clearly.
• Research the cited mark’s strength. Search for third-party uses and registrations. A crowded field weakens the opposition.
• Use evidence where you have it. Declarations, examples of coexistence, and market evidence all carry real weight.
• Respond to every issue the Examiner raised. Leaving anything unaddressed is the fastest way to get a final refusal.

The Bottom Line

Likelihood of confusion is a nuanced analysis and no two cases are exactly alike. The DuPont factors give you a framework, but the outcome depends on how well the specific facts of your situation are developed and presented.

If you have received a Section 2(d) refusal and are not sure where to start, or if you want to get ahead of this before filing, reach out. I am happy to take a look.