A Statement of Use is a declaration that is filed by a trademark applicant stating that the applicant is using their trademark on goods and/or services that are available for sale in interstate commerce.
If trademark applicants aren’t using their mark in commerce, the applicant can file an Intent to Use Application and generally, if all goes well, receive a Notice of Allowance. Within six months of being granted the Notice of Allowance, the applicant generally has to prove that it is now using the mark or request up to five six-month extensions. The USPTO requires a specimen to prove use in commerce when a Statement of Use is filed.