What is a "likelihood of confusion" refusal?

A likelihood of confusion refusal occurs when the USPTO stops your application because the examiner has identified another trademark already registered by the USPTO that is similar to yours in a way that could potentially cause confusion in the market.

For applicants seeking trademark registration in other jurisdictions, it's worth mentioning that the US practice of refusing registration on behalf of previous trademark owners is particularly rigorous. In most jurisdictions, the burden of challenging a new application falls onto the previous trademark owners, who can do so during the opposition window, not the IP office.

What this means in practice is that while in other jurisdictions, the other owners might not come forward and oppose your application, in the US, a likelihood of confusion refusal cannot be avoided if another similar trademark exists.

However, we have to point out that the likelihood of confusion refusals happens very often and can be successfully overcome. If you've received one, the most suitable strategy will depend on your case - your mark, the other mark, goods and services provided under the two marks, who the other holder is and what presence they have in the market, etc. Therefore, it's highly recommended to consult a trademark attorney who can help you understand your options and choose the best course of action.