1104.03(b) The "Blackout Period" 
Under 37 C.F.R. §2.76(a)(1), the USPTO will not review an amendment to allege use filed after the date that the application is approved for publication by the examining attorney. Under 37 C.F.R. §2.88(a)(1), the USPTO will not review a statement of use filed before the date of issuance of the notice of allowance. These two rules combine to create a time period when neither an amendment to allege use nor a statement of use may be filed. This period is known as the "blackout period." An applicant will not be permitted to electronically file an amendment to allege use or statement of use during the blackout period using TEAS. Any permitted paper-filed amendment to allege use or statement of use (see TMEP §301.02) submitted during this period will be deemed untimely and the fee refunded. In re Sovran Fin. Corp., 25 USPQ2d 1537 (Comm’r Pats. 1991). See TMEP §1104.03(c) regarding processing amendments to allege use filed during the blackout period.
Intent-to-use applicants who filed under 15 U.S.C. §1051(b) are encouraged to check the TSDR database on the USPTO website at https://tsdr.uspto.gov/ to determine the status of the application before filing an amendment to allege use.
If a review of the prosecution history of the application shows that the application has been approved for publication and a notice of allowance has not issued or was cancelled, the blackout period is in effect and an amendment to allege use should not be filed. The applicant should instead wait until the notice of allowance issues and then file a statement of use.