An opposition proceeding is commenced by filing in the Office a timely notice of opposition with the required fee. The notice must include proof of service on the applicant, or its attorney or domestic representative of record, at the correspondence address of record in the Office, as detailed in §§ 2.101(b) and 2.119.

Any person who believes that he, she or it would be damaged by the registration of a mark on the Principal Register may file an opposition addressed to the Trademark Trial and Appeal Board and must serve a copy of the opposition, including any exhibits, on the attorney of record for the applicant or, if there is no attorney, on the applicant or on the applicant’s domestic representative, if one has been appointed, at the correspondence address of record in the Office. The opposer must include with the opposition proof of service pursuant to § 2.119 at the correspondence address of record in the Office. If any service copy of the opposition is returned to the opposer as undeliverable, the opposer must notify the Board within ten days of receipt of the returned copy. The opposition need not be verified, but must be signed by the opposer or the opposer’s attorney. Electronic signatures are permissible and required for oppositions filed through ESTTA.