Can I perfect a foreign priority claim after my patent has been issued?

Can I perfect a foreign priority claim after my patent has been issued?

No, you cannot perfect a foreign priority claim after your patent has been issued if the claim was not timely filed during the pendency of the application. As stated in MPEP 216.01:

“A reissue application can be filed to correct the failure to adequately claim priority under 35 U.S.C. 119(a)-(d) or (f) in an issued patent. However, a reissue application cannot be used to perfect a claim for priority benefit under 35 U.S.C. 119(a)-(d) or (f) where the claim for priority benefit was not timely filed during the pendency of the application that issued as the patent for which reissue is sought.”

This means that if you missed the deadline to file the priority claim or the required certified copy of the foreign application during the original patent application process, you cannot use a reissue application to retroactively perfect the claim after the patent has been issued.