What factors would the USPTO consider when refusing to register a trademark?

Each trademark application is assigned to a Trademark Examiner who examines the application for compliance with federal law. Likelihood of confusion between the mark of the applicant and a mark already registered or in a prior-filed pending application is the common reason for rejection.

In the ex parte examination of a trademark application, a refusal under §2(d) is normally based on the examining attorney’s conclusion that the applicant’s mark, as used on or in connection with the specified goods or services, so resembles a registered mark as to be likely to cause confusion.

The issue is not whether the respective marks themselves, or the goods or services offered under the marks, are likely to be confused but, rather, whether there is a likelihood of confusion as to the source or sponsorship of the goods or services because of the marks used thereon.

The examining attorney must conduct a search of USPTO records to determine whether the applicant’s mark so resembles any registered mark(s) as to be likely to cause confusion or mistake, when used on or in connection with the goods or services identified in the application. The examining attorney also searches pending applications for conflicting marks with earlier effective filing dates. The examining attorney must place a copy of the search strategy in the record.

If the examining attorney determines that there is a likelihood of confusion between applicant’s mark and a previously registered mark or marks, the examining attorney refuses registration of the applicant’s mark under §2(d). Before citing a registration, the examining attorney must check the automated records of the USPTO to confirm that any registration that is the basis for a §2(d) refusal is an active registration.

Also, if USPTO records indicate that an assignment of the conflicting registration has been recorded, the examining attorney must check the automated records of the Assignment Recordation Branch of the USPTO to determine whether the conflicting mark has been assigned to applicant. Source: USPTO