Interference Proceedings (Trademark) Law and Legal Definition

Interference Proceedings under trademark law is a proceeding before the Trademark Trial and Appeal Board. The proceeding is near-obsolete, and reserved for those cases showing extraordinary circumstances. An interference proceeding is declared by the Commissioner of Patents and Trademarks upon petition. Priority of use is the major issue in these proceedings. Generally, the interference proceeding will not be granted unless the issue of priority could not be addressed most efficiently in an opposition or cancellation proceeding.

Pursuant to 15 USCS § 1066, an interference proceeding determines who was first user and therefore the rightful owner of a trademark. Interference proceedings are available only for Principle Register trademarks. A condition precedent to an interference proceeding is that one of the marks but not both is registrable. The junior party, who is the one with the latest filing date, bears the burden of proof.