If you applied for a trademark under an “intent-to-use” (also called Section 1(b), you will need to file a Statement of Use to finalize your trademark registration. If you miss the deadline to file a Statement of Use, your trademark application will be abandoned.
The USPTO will issue a Notice of Allowance six months before you need to file either a Statement of Use or a six month extension.
In order to file a Statement of Use, you must be actively selling your branded products or rendering your services in the United States.
Once you file a Statement of Use, you cannot submit proof of use that happened after you filed the original proof of use. If your filing is found to be insufficient then you will need to start the application process anew.
You can file for a six month extension to this requirement up to a total of five times.
If at any time you miss a deadline, you will have six months to revive the application for a fee. After that grace period, the application will be dead and cannot be revived