Actual use of your trademark in commerce is a requirement to receive a federal trademark registration. When you file a section 1(a) use-based application, you must provide a first use in commerce date and a specimen proving your use when the application is filed.
If you file your trademark application as a section 1(b) intent-to-use application, you do not provide the office with a first use date or a specimen because you have not started using your mark in commerce. However, the USPTO will not issue a registration until you provide the office with (1) the date your mark was first used in commerce for the good and/or services specified in the application and (2) a specimen proving your use. TMEP 902. You provide this information in a “Statement of Use.”
A Statement of Use is filed generally after the USPTO issues a notice of allowance indicating that your registration is ready to be granted. A notice of allowance is issued after the application is published for opposition and not successfully opposed. TMEP 1106.1.
A statement of use may be filed within six months of the notice of allowance. A certain number of additional six-month extensions of time can be obtained if additional time is necessary to use the mark for the goods/services and there is an ongoing intent to use the mark for the goods/services claimed in the application.