How does the USPTO act in case of a likelihood of confusion?

If the USPTO examiner identifies an existing registered or pending mark that is similar to the applied-for mark and the goods or services overlap sufficiently to create a likelihood of consumer confusion, the examiner issues an office action citing likelihood of confusion as a ground for refusal.

The examiner doesn’t just compare marks word-for-word or letter-for-letter. They compare multiple factors, such as visual, phonetic, and conceptual similarity; the similarity of the respective goods and services; the channels of trade and classes of consumers; and the strength of the cited mark. The marks do not need to be identical; a finding of likely confusion is sufficient grounds for refusal.

The applicant has a set window (typically three months, extendable to six) to respond to the office action. The response can include legal arguments challenging the examiner's reasoning, evidence that the marks coexist without confusion in practice, a consent agreement from the owner of the cited mark, or a narrowing of the goods and services list to avoid the area of conflict. If the examiner is not persuaded, the refusal is made final, and the applicant can appeal to the Trademark Trial and Appeal Board (TTAB).