Advisory action is issued by USPTO if reply to final office action is within 2 months from mailing date of final office action and also reply time to Final Office Action including Advisory is 3 months from its mailing date. What if advisory action is received after 3 months from mailing date of final office action ?
As indicated in the Advisory Action, the date for reply will be the date of the Advisory Action as it is later than the 3 month date set forth in the final Office Action. As you will respond to the Advisory Action after the date of the Advisory Action, you will need a one-month extension if filed within one month of the Advisory Action. Of course, you will still need to resolve everything within 6 months of the date of the final Office Action, be it by filing an RCE or Notice of Appeal, getting the examiner to allow the case, or letting it go abandoned.